Journal of Rocket-Space Technology

REGARDING THE NEED TO IMPROVE THE QUALITY OF CERTAIN STANDARDS OF THE REGULATORY LEGAL FRAMEWORK

Mykhailo Khorolskyi, Oleg Bondarenko, (Author) — Tue, 30 Dec 2025 00:00:00 +0200

The objects of machine engineering in sectors such as rocket and space, aviation, and defense are currently the most developed. They can provide a boost for the development of other sectors and accelerate the reconstruction of Ukraine's destroyed infrastructure in the near future at a high scientific and technical level. Highly qualified specialists and high-quality legislative and regulatory acts are needed for this, which should be based on fundamental laws that will ensure that learners acquire the relevant knowledge. According to the authors, such fundamental documents are the Laws of Ukraine 'On Metrology and Metrological Activity', 'On Standardization', 'On Technical Regulations and Conformity Assessment', as well as the normative-technical and normative-legal acts based on them. They should provide educational institutions with the opportunity to prepare future highly qualified specialists for the quality reconstruction of many sectors of the economy in the near future. The proposed systemic model of product quality should serve as the foundation for preparing highly qualified specialists, producing high-quality products, and the fastest reconstruction of Ukraine. However, some regulatory legal acts, including national standards of Ukraine, in the opinion of the authors of this article, do not meet the quality criteria, particularly regarding consistent terminology, which the national standardization body has proposed to change in some basic national standards of Ukraine, contrary to modern dictionaries of the Ukrainian language, for example, DSTU 3321:2003 "System of Design Documentation. Terms and Definitions of Basic Concepts" and DSTU 2391:2003 "System of Technological Documentation. Terms and Definitions of Basic Concepts". At the same time, the principles that were proposed by the national standardization body in another basic National Standard of Ukraine DSTU 1.5:2015 "National Standardization of Ukraine. Rules for the development, presentation, and formatting of national regulatory documents" have been violated, thus initiating contradictions in the field of standardization in general and even within a single standard. The article includes photographs of terminological discrepancies with contemporary dictionaries of the Ukrainian language and provides recommendations for their elimination.

FEATURES OF USING THE ELECTROMAGNETIC ANGULAR STABILIZATION SYSTEM OF SPACE VEHICLES

Aleksandr Polosmak, Olena Hrebenkina, Anatoly Kulabukhov (Author) — Mon, 29 Dec 2025 23:00:34 +0200

Virtually all spacecraft (SCs) use an electromagnetic angular orientation and stabilization system (AOSS) in low orbits. Its widespread use is primarily due to the simplicity of practical implementation (relatively cheap magnetometers are used as sensors, and electromagnets as actuators), and secondly, for unloading flywheel engines. The purpose of the work is to conduct an analytical review of the features of using electromagnetic AOSS. The models and characteristics of the Earth's magnetic field and the nature of the interaction of the Earth's magnetic field with the magnetic field of the spacecraft are considered. In a first approximation, near the Earth's surface (up to three of its radii), the Earth's magnetic field is represented as a magnetic dipole, the axis of which is inclined to the Earth's axis of rotation. This tilt gradually changes, requiring the model to be corrected every 5 years. In reality, the Earth's magnetic field differs from the theoretical model due to the appearance of so-called magnetic anomalies. The characteristics of these anomalies and their impact on the spacecraft are considered. The characteristics of these anomalies and their impact on the spacecraft are considered. An analysis of the errors of the electromagnetic AOSS is carried out, including: the model of the Earth's magnetic field, relative to which the angular position of the spacecraft is determined according to magnetometer measurements, has deviations from the real magnetic field; when the axis of the spacecraft coincides with the magnetic field line, the rotation of the spacecraft around this axis becomes impossible; the determination of magnetometer measurements of the Earth's magnetic field vector projections is significantly affected by magnetic fields created by electromagnets (EMs) and spacecraft instruments; as the spacecraft moves in orbit, the Earth's magnetic field changes its position in space; the steering torque created by the EMs is small, which leads to a significant stabilization time. The main factors that affect the accuracy of angular stabilization of the spacecraft and methods that allow reducing their impact on both the accuracy of orientation (determination of the angular position of the spacecraft in space) and the accuracy of stabilization (maintaining the angular position of the spacecraft) are determined. Creating more effective electromagnetic algorithms AOSS can be achieved through the use of artificial intelligence (AI).

NUMERICAL VALIDATION AND PARAMETER ANALYSIS OF A FIVE-PHASE PITCH PROGRAM FOR LAUNCHING SPACECRAFT INTO CIRCULAR ORBITS

Ruslan Keba, Anatoly Kulabukhov (Author) — Mon, 29 Dec 2025 20:49:11 +0200

The aim of this study is the systematic numerical validation of a semi-analytical five-phase pitch program model (FPPM), which is critically important for optimizing the trajectory of the active flight phase of launch vehicles (LV) performing orbital insertion into circular orbits. The validation is carried out by applying the model to numerical configurations of launch vehicles from two fundamentally different classes: Falcon 9 (characterized by high thrust-to-weight ratio and using LOX/RP-1) and JAXA H3 (distinguished by high specific impulse and using LOX/LH2). The ultimate goal is to establish and quantitatively analyze the dependence of optimal pitch control parameters on the altitude of the target circular orbit. The proposed FPPM parameterizes the angular profile of LV motion on the active segment, ensuring continuity of angular velocity and angular acceleration. The model is governed by a set of five key variables (t1, k2, k3, t4, t5), where the dimensionless coefficient defines the relative duration of the phase with constant angular velocity. Optimization was conducted via numerical integration of the full system of equations of motion of the LV center of mass using a grid search method in a multidimensional parameter space. The objective function minimized a composite error metric representing deviations from the final orbital constraints (prescribed orbital altitude and circular velocity ). The numerical simulations yielded sets of quasi-optimal FPPM parameters for orbital altitudes of 400–700 km for Falcon 9 and 1000–1200 km for H3. A stable and universal trend was identified: an increase in target orbital altitude correlates with an increase in the total insertion time and a significant growth of the parameter . Increasing directly leads to a reduction of the peak angular velocity , indicating the necessity of generating a flatter (more shallow) trajectory profile to effectively minimize gravity losses. The resulting quantitative dependencies demonstrate strong universality, as identical tendencies were observed for launch vehicles with fundamentally different dynamics. The obtained results may serve as reliable heuristic guidelines for rapid preliminary synthesis of ascent trajectories for a wide class of launch vehicles.

COMPARATIVE ANALYSIS OF THE NORMALITY OF STATISTICAL CRITERIA FOR SAMPLES OF CONTAMINATED DATA

Oleksii Klymenko, Serhii Vovk (Author) — Mon, 29 Dec 2025 14:24:33 +0200

The paper considers the influence of contaminated samples with anomalous observations on the reliability of statistical analysis results and hypothesis testing for sample homogeneity. The main focus is on visual data analysis as an effective means of preliminary research. The use of histograms, scatter plots, and density estimates allows for the visual identification of outliers, the assessment of the distribution shape, and the detection of differences between samples. The purpose of the study is to evaluate the robustness of popular statistical criteria for testing the normality of distribution in the presence of contamination in small samples. The scientific novelty lies in the quantitative study of the impact of different types of contamination on the results of popular criteria, as well as in the practical assessment of their behavior under conditions of violation of assumptions about data homogeneity. The practical novelty lies in the development of recommendations for practitioners on the selection of the optimal criterion when analyzing samples with possible anomalous observations, taking into account the stability of statistical methods. Research methods include numerical modeling of samples with controlled introduction of structural contaminants, assessment of the frequency of false rejections/acceptance of the null hypothesis, as well as comparative analysis of the results obtained using the following statistical criteria: Student's t-test for comparing the mean values of two samples; the Kolmogorov-Smirnov one-sample test to verify the conformity of the empirical distribution with the theoretical one; the Anderson-Darling criterion to verify the normality assessment; the Kolmogorov-Smirnov two-sample test to verify the homogeneity of two distributions. The results of the study showed the importance of choosing the appropriate criterion depending on the sample size and the expected level of contamination. Presenting the average values and ranges for N repetitions of the experiment allows for a visual assessment of the stability and reliability of each test in the presence of contaminated data. Based on the experiments conducted, practical recommendations are proposed for the preliminary diagnosis of samples and the selection of the optimal approach to testing hypotheses in the presence of contaminated data.

APPLICATION OF CORRECTION COEFFICIENTS TO THE SIGNAL AMPLITUDES FROM REFLECTORS IN ULTRASONIC NON-DESTRUCTIVE TESTING REFERENCE BLOCKS

Pavlo Sazonov, Svitlana Klymenko (Author) — Mon, 29 Dec 2025 09:52:13 +0200

Ultrasonic non-destructive testing (NDT) is one of the most widely used methods for the technical diagnostics of complex engineering structures. A critically important aspect of this method is not only the ability to detect the presence of a defect, but also to quantitatively determine its size, which directly influences the assessment of an object’s technical condition and the decisions regarding its further operation. In traditional ultrasonic NDT systems, the most common approach to estimating defect size is the amplitude method, which is based on comparing the amplitude of the signal reflected from a defect with the amplitude of a reference reflector in a test block. Despite its popularity and apparent simplicity, the amplitude method has significant metrological limitations, primarily associated with the poor reproducibility of amplitudes obtained from nominally identical defect simulators in calibration or reference blocks. Long-term experience in verification, calibration, and production of such blocks shows that signal amplitudes may differ by 4–10 dB even when geometric and technological requirements are met with high precision. Such a deviation is critically important, as it changes the estimated reflecting area by several times, leading to incorrect evaluations of defect size. The main causes of this phenomenon include acoustic inhomogeneity of materials, variations in the actual geometry and surface roughness of the defects, wave and diffraction effects, differences in the formation of the acoustic beam by the transducer, and the influence of ultrasonic attenuation in real materials. Collectively, these factors give rise to the problem of low reproducibility of amplitude parameters, which is one of the key obstacles to improving the accuracy and stability of ultrasonic NDT results. This article proposes a new approach to compensating for such discrepancies, based on comparing the amplitude of the signal reflected from a real flat-bottom hole with that of a signal reflected from a quasi-infinite surface, whose amplitude is stable and reproducible in similar materials. Based on an analysis of acoustic-path equations for the far field, a mathematical model of an amplitude correction factor is formulated. The developed model makes it possible to determine the difference between the theoretical and actual amplitude ratios and to compensate for uncontrolled factors that arise during real measurements. In addition, the study includes an analysis of the sources of uncertainty associated with the proposed correction.

EQUIPMENT AND MATERIALS FOR HALL-EFFECT THRUSTER RESEARCH: GLOBAL PRACTICES AND UKRAINE’S PATH FORWARD

Viktoriia Chorna, Olena Karpovych (Author) — Mon, 29 Dec 2025 09:27:45 +0200

The Hall-effect thrusters (HET) operate within the 100–1000 W power range to function as primary propulsion systems for small satellite constellations and all-electric GEO station-keeping operations and future deep-space exploration missions. The paper conducts an in-depth 2025 assessment of worldwide facilities and diagnostic tools and construction materials which enable HET development and qualification testing. The review examines Ukrainian HET development activities through Space Electric Thruster Systems (SETS) as a private company and academic research institutions. The research demonstrates Ukraine operates a modern vacuum-diagnostic facility (SETS facility with 2–3 m³ volume and cryogenic panels and thrust-stand precision of 0.005 mN) which confirmed the ST-25 flight model and ST-40 near-flight version [4]. The research shows that Hall thruster testing requires vacuum chambers exceeding 10 m³ to support 1–5 kW thruster and cluster configurations and extended open experiments beyond 15,000 hours. The review combines data from Goebel & Katz (2008/2024) monographs with technical reports and scientific articles published between 2015 and 2025 to determine the fundamental innovation areas which consist of additive manufacturing for ceramic components and multi-layer dielectric coating development and optical diagnostic systems and artificial intelligence for operational performance enhancement. The research data enables the choice of equipment and materials needed to construct a modern Ukrainian HET research facility which focuses on small-spacecraft propulsion and deep-space exploration.

ALUMINUM SHAVINGS USING THE TECHNOLOGY OF PRODUCING MODIFIERS FOR PROCESSING ALLOYS

Serhii Polishko (Author) — Mon, 29 Dec 2025 09:13:54 +0200

Modern metallurgy requires efficient and cost-effective methods to improve the properties of metal alloys. One promising approach is the development and implementation of new modifiers that not only enhance the mechanical characteristics of materials but also reduce their gas saturation and the number of non-metallic inclusions. This study explores the possibility of using aluminum chips as raw material for producing multicomponent modifiers, which helps to reduce production costs and improve the quality of cast aluminum alloys. The relevance of this research is driven by the need to optimize metallurgical processes in the context of limited energy resources. In traditional technologies, the deoxidation and modification of aluminum alloys are carried out using ingot aluminum, leading to significant energy consumption. The proposed method of recycling aluminum chips involves pressing them into briquettes, which provide a complex effect: deoxidizing, micro-alloying, and modifying the structure of the alloy. Experimental melts were conducted at PJSC "Dnipro Metallurgical Plant." During the tests, the influence of briquetted aluminum chips on the chemical composition, microstructure, and mechanical properties of the AL2 alloy was evaluated. Analysis results showed that the use of such modifiers ensures the uniform distribution of alloying elements and improves the performance characteristics of the final product. The scientific novelty of this study lies in proving the possibility of obtaining cast aluminum alloy AL2 from raw material consisting of crushed chips of the same metal. A detailed analysis of the technological process, chemical composition, and mechanical characteristics of the modified alloy was conducted for the first time, confirming the compliance of the obtained products with regulatory requirements. The study’s conclusions confirm the feasibility of implementing the developed technology in industrial production. The use of pressed briquettes made from aluminum chips significantly reduces energy costs, improves the quality of metal products, and increases production profitability, making the proposed method a promising solution for modern metallurgy.

FUNCTIONAL DATA PROCESSING MODEL IN OBSERVATION OF TECHNICAL AND NATURAL OBJECTS

Viktoriia Klym, Oleksii Fedorenko (Author) — Mon, 29 Dec 2025 07:49:37 +0200

Development of science and technology is characterized by a rapid increase in the complexity of objects of knowledge, among which both natural phenomena and high-tech complexes, particularly those of rocket and space purpose, occupy a central place. The growing volume of information and the complexity of its processing sharply intensify the need for new information and computer technologies capable of providing reliable support for the management, monitoring, assessment, and analysis of complex systems. An important conceptual stage in the construction of any such technology is the development of its functional model. In this context, a systems approach, which allows considering complex objects as integral entities with networks of internal and external connections, is gaining increasing importance. For the rocket and space industry, where objects are dynamic, open, and stochastic systems, this approach is particularly relevant, as they demonstrate all the features of complex systems: a significant number of interconnected elements, hierarchy, the presence of feedback loops, adaptability, and the fact that the properties of the whole are not reducible to the sum of the properties of its parts. Effective monitoring of multidimensional time series requires specialized processing methods. The article substantiates the feasibility of classifying complex systems, which include rocket complexes, based on a set of key features: nature, dynamics, determinism, interaction with the environment, etc. Particular attention is paid to the analysis of the specifics of working with autocorrelated data, characteristics of rocket and space systems. The process of their processing is considered, which includes data collection, preliminary processing, autocorrelation analysis, and the application of statistical or machine methods for forecasting and assessing the object's state. This creates a scientific basis for the further improvement of measurement processing methods aimed at increasing the accuracy and efficiency of monitoring complex technical systems in real-time, which is especially important for the rocket and space industry.

INFORMATIVENESS OF THE CRITERIA OF STATISTICAL HOMOGENEITY OF SAMPLES OF EXPONENTIAL MEASUREMENTS

Nadiia Fedoriatska, Dmytro Astakhov (Author) — Mon, 29 Dec 2025 06:42:17 +0200

In the paper, examines the statistical homogeneity of samples of independent random variables with an exponential distribution. It is known that one of the main characteristics of the reliability of rocket and space systems is the law of distribution of its resource. However, an exponential distribution is used to determine unexpected failures. This paper aimed to conduct computational experiments to verify the requirement that the measured parameters be statistically homogeneous. In practice, probability theory most often uses parametric verification criteria based on the assumption that statistical data obey a normal distribution. However, in some cases, such assumptions lead to erroneous conclusions. In this paper, nonparametric criteria, such as the Spearman rank test and the Shirahate test, which incorporate information about the state of technical objects, were used to verify homogeneity. A distinctive feature of these criteria is their flexibility, which allows their use in problems where the conditions for applying parametric methods are not met. The theory suggests that the Shirahate test, which is characterized by the formation of complex ranks, is more informative. This article explored the informative value of statistical homogeneity in random variable samples for three types of probability distribution functions with small sample sizes. After constructing experimental measurement sample models, computational experiments and a visual and graphical analysis of the histograms of the Spearman and Shirahate tests were conducted. In accordance with the problem conditions, an analogue of the Shirahate test was tested for a sample length of n = 10, yielding an empirical probability of P*(n) = 0,9504, confirming the hypothesis of statistical homogeneity for random variable samples with an exponential distribution.

THERMOMECHANICAL BEHAVIOR AND MICROSTRUCTURE OF LASER-HYBRID AND ELECTRON-BEAM WELDED JOINTS OF TITANIUM ALLOYS

Svitlana Kyrylakha (Author) — Mon, 29 Dec 2025 00:00:00 +0200

This study presents a comprehensive thermomechanical analysis of residual stress formation and structural evolution during laser-hybrid welding of Ti-6Al-4V titanium alloy. The main objective is to evaluate the influence of process parameters on temperature distribution, weld morphology, and residual stress development. Finite element modeling (FEM) was employed to simulate heat transfer, thermal gradients, and plastic deformation, and the results were validated using experimental data from laser-GTA and electron beam welding studies. Microstructural analysis of the weld metal (WM), heat-affected zone (HAZ), and base metal (BM) revealed a gradient of α and β phases, influenced by local thermal cycles. Results demonstrate that laser-hybrid welding produces a narrower fusion zone and a reduced HAZ compared to conventional TIG and EBW methods, enhancing structural uniformity. Longitudinal residual stresses were highest along the weld centerline but were significantly reduced after ultrasonic impact treatment (UIT), confirming its effectiveness in stress relaxation. Comparative analysis indicates that LHW provides superior control over thermal gradients and microstructure, ensuring improved mechanical performance and dimensional stability of welded components. The study establishes correlations between energy input, weld geometry, microstructural features, and residual stress distribution, which are critical for optimizing welding parameters. The findings contribute to designing advanced titanium structures with enhanced reliability for aerospace and transport engineering applications. Overall, the results highlight that the combination of laser-hybrid welding and UIT represents a promising approach for manufacturing high-performance titanium alloy components.

AUTOMATED CONTROL OF FIBER TENSION IN THE IMPREGNATION PATH DURING FILAMENT WINDING OF COMPOSITE SHELLS

Yukhym Myhovych (Author) — Mon, 29 Dec 2025 00:00:00 +0200

This paper presents the results of theoretical and experimental research on the process of forming composite shells by filament winding, focusing on the problem of stabilizing fiber tension during passage through the resin impregnation path. Maintaining constant fiber tension is a key factor in composite manufacturing since its fluctuation leads to irregular layer placement, internal stresses, delaminations, and deterioration of the final product’s mechanical properties. Particular attention is paid to the impregnation stage, where fiber tension varies due to changes in the viscosity of a hot-curing epoxy resin during continuous operation. A mathematical model of the roller system in the impregnation path was developed based on the Euler–Eytelwein equation, which describes the dependence of fiber tension on the wrap angle and friction coefficient of each roller. The concept of an effective friction coefficient was introduced to account for the influence of temperature, partial polymerization over time, and the degree of fiber wetting. The proposed model allows for quantitative evaluation of tension variation in real time and enables optimization of process parameters for stable operation. To ensure constant fiber tension, a hardware–software automatic control system was developed using an Arduino Uno microcontroller. The system includes an HX711 load cell amplifier for real-time tension measurement, an MG996R servo motor for adjusting the movable roller’s angle, and a PID controller that compensates for disturbances caused by resin viscosity fluctuations and winding speed changes. The developed control algorithm maintains the fiber tension within ±5% of the target value, even when resin viscosity increases by 30–40% during operation. Experimental validation confirmed the accuracy of the mathematical model and the efficiency of the automated control strategy. The proposed system can be applied both in laboratory studies of filament winding and in industrial installations to ensure stable manufacturing of composite shells, including casings of solid-propellant rocket motors and other high-performance composite structures.

PROSPECTS FOR USING AI METHODS TO PREDICT THE GLACIATION OF UAV BEARING SURFACES

Volodymyr Strembovskyi, Artur Kruhlyi (Author) — Mon, 29 Dec 2025 00:00:00 +0200

Icing of aircraft lifting surfaces is a safety risk factor in both civil and military aviation. Ice accretion on lifting surfaces leads to degradation of the aerodynamic characteristics of the aircraft, reducing the maximum lift coefficient by 20–80% and increasing the drag coefficient by 50–100%. The problem is particularly acute for small unmanned aerial vehicles (UAV), which operate at low Reynolds numbers and cannot utilize traditional anti-icing systems due to weight, size, and power constraints. This study aims to comprehensively analyze current research on aircraft component icing processes and evaluate prospects for applying machine learning methods to predict ice accretion. The research presents a systematic review of physical mechanisms governing rime, glaze, and mixed ice formation, experimental testing methods in icing wind tunnels, and contemporary CFD tools (LEWICE, FENSAP-ICE, GlennICE). The study substantiates the feasibility of hybrid CFD–ML approaches where traditional numerical simulations generate training datasets for constructing fast surrogate models. Using 3,200 icing simulations on the symmetric NACA0012 airfoil across wide ranges of six governing parameters (velocity, angle of attack, temperature, LWC, MVD, exposure time), a multilayer perceptron was developed to predict iced profile contour coordinates. The model demonstrates mean absolute error of 0.741 cm (1.5% chord) on the test set, with highest accuracy for rime ice (0.11 cm) and acceptable results for more complex glaze and mixed ice morphologies. Results confirm the neural network approach effectiveness as a rapid engineering analysis tool and establish foundations for integrating such models into automated design systems and adaptive ice protection systems for UAV. The developed methodology enables real-time ice shape prediction without computational overhead of full CFD simulations, facilitating development of intelligent anti-icing systems.

MANAGING THE CONNECTION OF ALTERNATIVE POWER SOURCES TO EXISTING GRID

Marko Nalbandian, Valeriy Mazurenko (Author) — Sat, 27 Dec 2025 23:50:14 +0200

The present study posits that one of the most efficacious strategies for enhancing the reliability of energy supply systems is the decentralization of electric energy production. In the contemporary era, the predominant energy model involves the end user integrating consumption and production of energy through the utilization of alternative sources. This prompts the consideration of several technical issues, including automatic generation control, the assessment of energy quality from diverse sources, and the reliable switching of these sources. Existing switching methods are designed for a "switching center", defined as a single point of connection of all sources to the switching system. This design significantly complicates the connection of new sources and, consequently, the creation of a distributed power generation system. Firstly, it is important to note that such switching centers constitute a single point of failure. In the event of damage to such a center due to natural or technogenic factors, there will be an interruption to the supply and distribution of electric energy. Furthermore, the consumer's electricity supply connection scheme is typically designed during the construction stage of the facility, which complicates or renders impossible the subsequent connection of alternative sources (e.g. solar generation systems or other renewable energy sources). These alternative sources can occupy substantial areas and be located at considerable distances from the switching center. In addition, the methods of source switching and load balancing that have been considered in the literature do not implement electrical energy quality monitoring. Nor do they take into account the compliance of its parameters (e.g. voltage, frequency, deviation of the AC voltage form from sinusoidal, stability over time, etc.) with the requirements of the standards. In order to enhance the existing schemes, a model is proposed that facilitates the distribution of power sources to the grid at numerous switching points, ensuring their synchronization and the monitoring of the energy quality from each source. The continuous monitoring and accumulation of statistical information, as well as the physical switching of each source to the grid, can be carried out using automated systems based on microprocessor controllers. These controllers constantly exchange information with each other regarding the parameters of the relevant sources. In accordance with the data presented, each controller generates an instance of a single distributed database for the purpose of making switching decisions.

IMPROVING THE ACCURACY OF THE INERTIAL MEASUREMENT MODULE USING REDUNDANT MEASUREMENTS

Pavlo Pashchela, Roman Turenko (Author) — Sat, 27 Dec 2025 22:50:14 +0200

The work is devoted to the study of inertial measurement modules with a redundant structure. Various layouts of inertial meters in their composition are studied and the possibility of increasing accuracy through the use of redundant measurements is investigated. Block layouts with four, five, and six accelerometers, the measurement axes of which are directed along a cone, are considered. Also, a layout of six inertial meters, located with their measurement axes opposite each other, is considered. All the considered layouts are simulated and the output signal of the inertial measurement module is visualized. For the opposite layout, a semi-real-life experiment was conducted, with digital data recording and subsequent processing of the recorded output signal. It is shown that the oppsite layout has significant advantages, reducing both the systematic and random components of the measurement error.

METHODOLOGY FOR REFINEMENT OF HYDRAULIC LOSSES IN THE DESIGN OF ADDITIVELY MANUFACTURED LIQUID ROCKET ENGINES

Volodymyr Sukachevskyi, Volodymyr Lipovkyi (Author) — Sat, 27 Dec 2025 00:00:00 +0200

The paper addresses the issue of accounting for hydraulic losses in the cooling channel of a liquid rocket engine (LRE) manufactured using the additive technology Laser Powder Bed Fusion (L-PBF). The purpose of the study is to develop a methodology that allows, at the preliminary design stage, to determine the influence of additive manufacturing features on coolant flow parameters and to ensure optimal thermal conditions for the combustion chamber operation. To achieve this goal, numerical simulation, analytical calculations, and comparative analysis of data obtained using «Астра», SolidWorks, and Wolfram Mathematica software were carried out. The proposed calculation algorithm is based on determining the roughness of the internal channel surfaces formed during the layer-by-layer metal powder printing process, which results in the so-called “staircase effect”. It is proposed to consider the influence of channel geometry variations and their inclination relative to the build axis on the surface roughness and the equivalent hydraulic diameter. The obtained results show that the use of additive technologies increases the roughness of cooling channels on average up to 10–130 μm, which leads to higher hydraulic losses and requires an increase in coolant inlet pressure to the chamber. For verification, a comparison between the developed model and the hydraulic calculation methodology was performed using numerical simulation in SolidWorks. The calculation error of 0.16 bar (up to 11%) confirms the correctness of the proposed approach. The theoretical significance of the work lies in the development of an approach for accounting the influence of surface roughness caused by additive manufacturing in the hydrodynamic design of LREs. The practical significance lies in the possibility of using the results to improve the accuracy of design calculations and to reduce the risk of combustion chamber overheating. The originality of the study consists in combining the analysis of additive manufacturing technological characteristics with the calculation of hydraulic losses, which has not previously been considered in engineering methodologies. Further experimental validation of the proposed methodology and its extension to various propellant combinations and cooling schemes are required.

CALCULATION OF THE COMBUSTION CHAMBER FOR A DUAL-FUEL HEATING BOILER OF MOBILE ROCKET COMPLEXES

Іhor Tokarskyi, Volodymyr Habrinets (Author) — Sat, 27 Dec 2025 00:00:00 +0200

Mobile missile systems require specialized heating systems that create stable conditions for calculations, launch preparations, and technical maintenance. The heating boilers used in these systems provide the necessary temperature conditions for computing equipment and personnel. To ensure the uninterrupted operation of such a heating system, it is advisable to make it multi-fuel. The paper proposes a method for calculating the combustion chamber and burners of a dual-fuel boiler intended for use as part of the auxiliary equipment of mobile missile systems. The choice of a combination of natural gas and diesel fuel is due to their availability and the absence of solid combustion products, which reduces the need for equipment maintenance. An algorithm for determining the amount of air required for complete combustion of fuel mixtures is presented, and the basic conditions for their ignition and stable combustion are considered. The design features of the most common gas and liquid fuel burners used in low-power water boilers are described, and formulas are given for calculating their geometric characteristics depending on pressure, fuel consumption per second, and the amount of air for combustion. A method for determining the volume of the furnace through heat release during combustion is presented, which allows establishing input data for further system design. For example, a calculation was performed for a 29 kW boiler, determining its volume, natural gas and diesel fuel consumption, as well as the relative oxygen consumption for complete combustion. The dimensions of the burner outlet channels, which ensure effective mixing of fuel with air, were analyzed separately. The results obtained demonstrate the possibility of creating a compact heat supply system that can be integrated into mobile missile complexes at the initial stages of their development and ensure the reliability of the calculation and launch subsystems in difficult operating conditions.

INFORMATION TECHNOLOGY FOR DECISION SUPPORT IN VIDEO SURVEILLANCE OF SPACE OBJECTS

Kostyantyn Sukovenko (Author) — Tue, 25 Nov 2025 19:23:58 +0200

The article considers the development and implementation of information technology for decision support in the field of video surveillance of space objects. Modern challenges associated with the identification, tracking and prediction of the trajectories of objects in low-Earth orbit are analyzed. The architecture of a system that combines video analytics, artificial intelligence methods and real-time decision-making algorithms is proposed. The key stages of video information processing are indicated, including object detection, classification and assessment of potential collision risks. The effectiveness of the developed technology is shown based on testing using simulation data and real video surveillance. The work is a contribution to improving space monitoring and ensuring the safety of space infrastructure.

THE CONCEPT OF THE UNIVERSAL (HABITAT AND AIRLOCK) MODULE OF MOON BASE

Yaroslav Lysenko, Andrii Pustovharov, Hennadii Osinovyj (Author) — Tue, 25 Nov 2025 19:12:03 +0200

The 21st century is characterized by fundamental changes in humanity's attitude towards outer space. Plans to move from research and exploration to colonization are being openly proclaimed. Space colonization primarily involves the colonization of celestial bodies, such as asteroids. But the main object to which attention is focused is the Moon, the Earth's natural satellite. Gradually, it is planned to ensure the permanent presence of people on the Moon, for which purpose lunar bases will be created. The peculiarity of the base creation process will be the step-by-step delivery of the base components (manned and unmanned modules, power plants, scientific and technological equipment, and vehicles) to the Moon. After some initial minimum of these components is concentrated on the Moon's surface, it will be necessary to combine them into one whole and put them into operation. Therefore, the task arises to ensure a sufficiently long presence of people on the Moon's surface, who will carry it out. At the same time it is necessary to provide people with conditions for living and working on the Moon. Numerous developments of manned space technology for the Moon have shown that conventional spacecraft are of little use for extended stays there and for preparing and conducting the aforementioned trips to the surface. Consequently, it is necessary to create a special object of technology that can perform several tasks. The universal module (habitat and airlock) will be the first outpost of the Earthlings during the creation of the lunar base. The purpose of the work was to create a conceptual design of the universal module. During the design, many factors were taken into account, in particular the capabilities of the launch vehicle – energy (which limits the mass of the module), as well as layout (which limits the size of the module). Functional metrics, such as the number of surface trips and total duration on the Moon, became important. The design of the module is developed, its equipment is described. The most rational arrangement of equipment and systems inside the module is determined. Some characteristics are obtained and its appearance is formed. The means of module delivery to the Moon, including a super-heavy space rocket, are described. The application of the latest design and calculation methods, including 3D modeling and finite element analysis, allowed the work to be carried out at a high level. The work performed allows us to conclude that the universal lunar base module is an important and promising means of lunar exploration.

REVIEW OF MATHEMATICAL MODELS FOR CALCULATING THE DEPTH OF PENETRATION OF A CUMULATIVE JET

Yevhen Boliubash (Author) — Tue, 25 Nov 2025 18:52:07 +0200

The development of effective and reliable separation systems and flight termination systems in rocket and space technology is a relevant task. Linear shaped charges are promising executive elements in these systems. One of the main design parameters determining their effectiveness is the penetration depth of the shaped charge jet into a barrier. However, the process of formation and penetration of the shaped charge jet of a linear shaped charge, especially with a semi-cylindrical cumulative liner, is complex, differs from axisymmetric charges, and is insufficiently studied, including in terms of accurate computational prediction of penetration depth. This creates a relevant scientific and technical problem related to the necessity of refining mathematical models for calculating the penetration depth of shaped charge jets of linear shaped charges. The aim of the work is a theoretical analysis of existing methods for calculating shaped charge jet penetration depth and the refinement of the mathematical model for determining the penetration depth of shaped charge jets of linear shaped charges with a semi-cylindrical cumulative liner. Theoretical research methods were used, including the analysis of literature sources and a comparative analysis of existing mathematical models of shaped charge jet penetration. The analysis showed that existing mathematical models have the following limitations: they are based on simplified concepts of the shaped charge jet formation process and do not accurately account for the complex formation process of shaped charge jets of linear shaped charges; they are semi-empirical and based on specific coefficients whose values are absent for the studied linear shaped charge configuration and barrier made of aluminum alloy grade 2219; most of them do not take into account the influence of stand-off distance and technological factors of linear shaped charge manufacturing. Based on the analysis of promising existing approaches (in particular, Orlenko's and Yefanov's models), mathematical models have been refined for determining the penetration depth of shaped charge jets into a semi-infinite barrier and the through-penetration thickness for a finite thickness barrier. The values of semi-empirical coefficients for the refined formulas obtained for a linear shaped charge with a diameter of 5 mm and a barrier made of aluminum alloy grade 2219 are provided. The systematized data and analysis results can be used in the educational process and during the development of pyrotechnic separation systems in rocket and space technology.

INTELLIGENT UAV AUTONOMOUS NAVIGATION SYSTEM BASED ON SEMANTIC IMAGE ANALYSIS

Illia Savchuk, Tatyana Kadilnikova (Author) — Tue, 25 Nov 2025 12:22:05 +0200

This paper addresses the critical scientific and technical problem of ensuring reliable autonomous navigation for unmanned aerial vehicles (UAVs) in challenging GNSS-denied environments. A comprehensive analysis of existing navigation methods reveals the limitations of classical approaches: inertial systems suffer from unbounded error accumulation, while traditional visual methods based on template or feature matching are highly sensitive to variations in illumination, weather conditions, and seasonal landscape changes. To overcome these drawbacks, a novel integrated intellectual system is proposed. The core of this approach is a paradigm shift from matching low-level visual features to analyzing the high-level semantic content of the observed scene. A robust semantic segmentation module was developed, utilizing a U-Net convolutional neural network with a lightweight MobileNetV2 encoder. This module processes images from the onboard camera in real-time, converting them into local semantic maps by classifying each pixel into stable categories such as buildings, roads, forests, and water. The absolute global position of the UAV is then determined by robustly matching this local semantic map with a pre-loaded global reference map using an efficient coarse-to-fine hierarchical search algorithm. To provide a smooth, continuous, and drift-free trajectory, a mathematical model for sensor fusion is implemented. It integrates the low-frequency, globally accurate semantic localization updates with high-frequency relative motion estimates from a visual-inertial odometry (VIO) system. This integration is performed optimally using an Extended Kalman Filter (EKF). Computer simulation results confirm the effectiveness of the proposed system, demonstrating its ability to successfully compensate for VIO drift and maintain a globally correct trajectory estimate. This approach paves the way for creating highly robust and truly autonomous navigation systems, significantly expanding the operational capabilities of UAVs in complex and contested environments.

US PATENTS ON ADPCM SYSTEM AND ITS APPLICATIONS

Muhanned Al-Rawi (Author) — Tue, 25 Nov 2025 07:20:42 +0200

The Adaptive Differential Pulse Code Modulation (ADPCM) has been standardized by the International Telecommunication Union (ITU) due to its significance and extensive applications within telecommunication networks. This paper provides a concise overview of the recent US patents related to ADPCM and its applications, covering the years 2017 to 2025. Additionally, the general architecture of ADPCM is discussed. The findings presented herein aim to inspire researchers and motivate further explorations in this domain.

ON THE DESIGN OF FREQUENCY DOWN-CONVERTER FOR SATELLITE COMMUNICATIONS SYSTEM

Mohanad Abdulhamid (Author) — Tue, 25 Nov 2025 06:39:05 +0200

Satellite communication has served as the foundation for television, radio, and telephone transmission for more than a century. These communications function at extremely high frequencies, primarily 6 GHz for uplink and 4 GHz for downlink. A satellite dish installed on a residence down-converts these high-frequency signals for more efficient utilization. Frequency down-converters are commercially known as Low-Noise Blocks (LNBs). LNBs are responsible for receiving, amplifying, and then down-converting these microwave signals to a lower range of intermediate frequencies. This down-conversion is essential as it enables the signal to be transmitted through relatively inexpensive coaxial cables, in contrast to the costly and impractical waveguides that would be necessary for transmitting the original microwave signals. This paper addresses the design of the three primary components that constitute a frequency down-converter: the Low Noise Amplifier (LNA), the Local Oscillator (LO), and the Frequency Mixer. The intermediate frequencies required for satellite applications typically range from 75 MHz to 900 MHz. This study designs a frequency down-converter that generates an intermediate frequency of 100 MHz. For an input radio frequency of 1 GHz, the oscillator will be designed to operate at a center frequency of 0.9 GHz.

NANOMATERIALS FOR THE DEVELOPMENT OF FLEXIBLE SOLAR PANELS

Hanna Rysenko, Tetyana Nosova, Stella Mamchur (Author) — Tue, 25 Nov 2025 06:23:18 +0200

The article explores the potential of employing nanomaterials to develop flexible solar panels suitable for application on space stations and satellites. It examines the properties and benefits of materials such as perovskites, organic polymers, and carbon nanostructures. Current technological challenges, especially those related to stability under prolonged radiation exposure, are analyzed, along with possible solutions to address these issues. The findings demonstrate that integrating nanomaterials enables the production of lightweight, highly efficient photovoltaic systems that are well-adapted to extreme conditions, marking a new generation of solar technology.

Keywords: nanomaterials, flexible solar panels, space stations, satellites, organic solar cells, radiation resistance.

NANO-ALLOYING OF ALUMINUM ALLOY

Stella Mamchur, Tetiana Nosova, Serhii Lazarets, Daria Kuts (Author) — Tue, 25 Nov 2025 05:48:19 +0200

This study investigates the technology of modifying the high-strength aluminum alloy V95 through the use of Al-Sc ligature, aimed at enhancing its mechanical properties, a key focus in the advancement of modern materials. The analysis centers on justifying the selection of scandium as a microalloying element, leveraging its ability to form stable strengthening phases and influence the alloy’s microstructure, alongside the development of heat treatment regimes based on an in-depth analysis of the Al-Sc phase diagram. The outcomes of experimental melts with the addition of 0.2–0.3 wt.% scandium were carefully evaluated, followed by an extensive examination of mechanical properties using the precision TIRAtest300 equipment, which ensured the accuracy of the collected data. The results indicate that scandium modification enhances the homogeneity and fine-grained structure of the alloy, significantly reduces anisotropy in mechanical performance, and markedly improves strength: tensile strength increased by 21.6%, and yield strength by 42.5% compared to the unmodified state. Proposed heat treatment regimes, including homogenization at 470°C for 8 hours to eliminate structural inhomogeneities and aging at 300°C to stimulate the formation of Al₃Sc phases, were identified as critical for maximizing the strengthening effect. Microstructural analysis, conducted with advanced techniques, confirmed a substantial improvement in structural uniformity and a reduction in anisotropy within the modified alloy, a vital factor for its practical implementation. The study offers practical recommendations for adopting scandium modification in aluminum alloys, highlighting the necessity of precise control over heat treatment parameters to achieve desired mechanical characteristics. The findings hold significant potential for application in industries requiring high-strength and lightweight aluminum alloys with enhanced structural properties, particularly in aviation and automotive sectors where material reliability is paramount.

ADDITIVE MANUFACTURING OF TITANIUM ALLOYS USING THE XBEAM METHOD WITH ANALYSIS OF MICROSTRUCTURE AND MECHANICAL PROPERTIES

Svitlana Kyrylakha (Author) — Tue, 25 Nov 2025 00:00:00 +0200

Additive manufacturing (AM) of titanium alloys has become one of the most promising approaches in aerospace engineering due to its potential to reduce production time and cost while maintaining high mechanical performance. This study provides a comprehensive review of the microstructural and mechanical characteristics of Ti-6Al-4V alloys produced by wire-based electron beam additive manufacturing (xBeam technology). The primary objective is to evaluate the influence of technological parameters on the formation of α+β-phase structures, mechanical properties, and defect control in large-scale components relevant to aerospace applications. The review focuses on the effects of current, voltage, and wire feeding rates during the xBeam process and their role in achieving defect-free, homogenous structures. Microstructural analysis based on SEM data indicates the formation of columnar β-grains and fine lamellar α-phase colonies oriented along the build direction. Mechanical properties reported for xBeam-fabricated Ti-6Al-4V include a yield strength of ~920 MPa, tensile strength of ~995 MPa, elongation of ~14%, and hardness near 340 HV. These values are comparable or superior to those obtained by traditional rolling and other AM methods such as WAAM and LPBF. Furthermore, the integration of TiC-reinforced composites is highlighted as a promising route to enhance wear resistance and structural stability. The advantages of xBeam for fabricating large-sized parts (up to 1 meter in length) are discussed, with examples of real aerospace components such as flanges and pipelines. Comparison with national research results underscores the technological maturity and practical feasibility of xBeam. The study concludes that this method offers a viable path for manufacturing high-performance titanium structures with controlled properties for aerospace and defense industries.

INFLUENCE OF MODIFICATION ON THE STRUCTURE AND PROPERTIES OF NICKEL HEAT-RESISTANT ALLOYS FOR SPACE SPACE TECHNOLOGY PARTS

Tue, 25 Nov 2025 00:00:00 +0200

Nickel-based heat-resistant alloys occupy a special place in modern rocket and space technology due to their exceptional heat resistance, high mechanical properties and structural stability at high temperatures and loads. These materials form the basis of critical components of aircraft and gas turbine engines, as well as structural elements operating in aggressive environments and at extreme temperatures. The reliability, durability and efficiency of these systems largely depend on the properties of the heat-resistant alloys used and, accordingly, on the methods of alloying, modification and heat treatment. One of the main methods of improving the properties of heat-resistant nickel alloys is modification, i.e. the targeted introduction of microimpurities or ultrafine components that can change the crystallisation process, microstructure formation, phase composition and morphology of the strengthening phase. In particular, the use of modification opens up huge opportunities for improving the properties of alloys in order to adapt them to specific conditions of use. This is especially important in the context of miniaturization of components and rising operating temperatures, when even a slight improvement in structural properties can lead to a significant increase in the service life of the component. Despite a significant amount of fundamental and applied research, many aspects of the influence of modifying elements on the microstructure and physical and mechanical properties of nickel alloys remain insufficiently studied. Further analysis is required by the mechanisms of action of individual modifiers, their interaction with key alloying elements and the effect on the kinetics of phase transformations during heat treatment. Thus, the relevance of such studies is due to the need for an in-depth study of the effect of modifiers on the structure and properties of heat-treated nickel alloys in order to develop more efficient new generation materials that meet the growing requirements for machine reliability and durability.

INCREASING THE EFFICIENCY OF A MONOFUEL RAMJET AIR-DETONATION ENGINE

Vitalii Stoliarchuk (Author) — Mon, 24 Nov 2025 23:09:01 +0200

The purpose of the study is to create a holistic system of experimental and numerical analysis of processes in a straight-flow air-detonation engine (SDE) with monofuel supply, as well as verification of analytical models taking into account the features of chemical kinetics. Approach - The paper presents the results of experimental studies of a straight-flow air-detonation engine (SDE) operating on monofuel — Pronit and Enit. The tests were carried out on an impulse wind tunnel (IAT) at Mach numbers from 4 to 8. The conditions for the formation of the detonation front, the influence of pulse frequency, channel geometry and throttling modes on combustion stability were studied. Special attention was paid to adapting the design of the inlet diffuser and the internal geometry of the chamber to high-altitude flight conditions. The efficiency of using different types of monofuels in terms of thrust, stability and temperature load was compared. The subject of study in the article is the processes that occur in the chamber of a straight-flow air-detonation engine installation of a combined acceleration cycle. Task: to consider promising concepts of multi-mode engines and to investigate the nature of the influence of operating parameters and design factors on increasing the efficiency of a compact detonation engine. Methods of solving problems: computational-analytical and computational-experimental. Numerical modeling was carried out in a software package using various turbulence models to evaluate viscous supersonic flows. Results: the results of the experiments made it possible to identify critical conditions for launching a detonation wave, establish the influence of the geometric characteristics of the combustion chamber on the stability of combustion, and also assess the temperature load on the structure. The feasibility of switching from the traditional combustion mode to the detonation mode in the context of increasing thrust efficiency and reducing specific fuel consumption is substantiated. The relevance of developing such power plants for promising aviation and space technology, in particular small aircraft, unmanned aerial vehicles and modular rocket systems, is determined. It was established that the SPDD with Pronit monofuel can provide a stable detonation regime at altitudes up to 20 km. The results obtained can be used in the creation of hypersonic aircraft and new generation power modules. A set of methods was applied: high-speed experimental research using a laboratory stand; diagnostics of pressure, temperature and detonation velocity parameters; numerical modeling based on the Navier–Stokes equations with reaction kinetics; the approaches of Heizer, Wilson and Lu for different levels of complexity of physical and mathematical models were used. The scientific novelty of the work lies in the comprehensive approach to the study of compact SPDD on monofuel, which combines detailed chemical and hydrodynamic models with real laboratory validation. For the first time, the influence of preheating, compression ratio and feed rate on the implementation of stable detonation in a monofuel system was systematically investigated. The practical significance lies in the possibility of using the obtained results in the design of compact energy-efficient detonation engines for autonomous systems, where weight-size, launch speed, and reliability are critical.

ON DRONE TECHNOLOGY

Mhnd Farhan (Author) — Mon, 24 Nov 2025 23:01:02 +0200

Unmanned aerial vehicles (UAVs) or unmanned aircraft systems (UAS) are other names for drones, which are aircraft that do not have a pilot on board. A human operator can control it remotely, or it can fly itself using pre-programmed flight plans that use sensors and computers on board. Applications for drones are many and include everything from photography and recreational flying to military surveillance and package delivery. Numerous industries use drones because they can carry out tasks that are hazardous, challenging, or impossible for people to do directly. In order to detect obstacles, drones frequently use cutting-edge technology such as GPS, sensors, cameras, and occasionally LiDAR. A brief explanation of earlier drone technology works is provided in this paper.

OPTIMIZATION PARAMETERS OF THE PNEUMATIC SYSTEM SEPARATION STAGE LAUNCH VEHICLE SPACE MISSION

Denis Udovichenko (Author) — Mon, 24 Nov 2025 20:51:12 +0200

Examine pneumatic system of separation stage, which ensure relative speed and include exclude pollution surface of space vehicle. Up to this time in this capacity push apart element system of separation widely use motor solid fuel. In connection with requirements raise till clean surface space vehicle ensuring minimum angle speed in modern space vehicle «Falcon» and «Delta» use pneumatic system separation represented system, which consist of tank gas, pushers, pipe-line, which connection tank gas and pushers, valve. Fundamental executive element creation relation speed pneumatic separation system is pushers. Constructively pushers are pneumatic cylinder plunger displays in frame, when closer modulator pressure in govern cavity, create requirement force, executive work for kinematic parameter system separation stage. On example system of separation «Cyclone-4M» launch vehicle formulate setting optimization problem, make up objective function, basic assumption and supposition. In the capacity of main limit use equalization preservation, in which work pushers transform in kinetic energy separation stage. In the capacity added limitation use limited coupled with fastness element constructional pushers and tank gas and material with it manufactory. For decision task use numerical computing method optimization design objectives alternating-variable descent method. Sens of method successive minimization facility along coordinate ruling, on each iteration dupe n step about quantity fact, on every step change one fact other stay fixed. On the basis data design create method determinate parameter pneumatic system, grant guidelines about determinate planning parameter system separation stage, adduce result decision task, determinate optimization correlation volume tank gas and pusher, optimization value pressure, count pushers and them geometric parameter. Give recommendation about design scheme pneumatic system separation. The result research gived valuable data for construction system separation stage and blocks of spacecraft launch vehicle and showed possible apply pneumatic system for separation stages. The material article were helpful scientific and engineers technician worker, which work above create construction of system separation stages and take up optimization system separation stages launch vehicle space setting.

EXPERIMENTAL STUDY OF THE AERODYNAMIC CHARACTERISTICS OF SMALL AIRCRAFT MODELS IN THE “FLYING WING” CONFIGURATION

Serhii Aleksieienko, Zoia Sazanishvili, Valerii Nekrasov (Author) — Mon, 24 Nov 2025 00:00:00 +0200

Significant interest in small unmanned aerial vehicles, which are widely used to solve such tasks as surveillance, communication, reconnaissance and other specialized missions in both civil and military spheres, as well as constantly increasing requirements for the efficiency of such vehicles, determine the relevance of research aimed at improving their aerodynamic characteristics. A feature of such vehicles is their operation in the range of low Reynolds numbers (Re ~10⁵…10⁶), which significantly affects the development of the boundary layer and the mechanism of flow disruption. The article presents an analysis of the results of experimental studies of the aerodynamic characteristics of small aircraft models according to the “flying wing” scheme, built on the basis of Clark and LRN profiles. The experiments were carried out in a subsonic wind tunnel using three-component weight measurements, as well as flow visualization methods. The models were created with the implementation of variable wing profile thickness along the span, the use of swept and V-shape, ridge tips and were manufactured using the 3D printing method. It was established that both models are characterized by the formation of a separation bubble even at small angles of attack, which leads to an increase in drag. A comparative analysis of the dependences of lift, drag and aerodynamic quality on the angle of attack showed that the model with the Clark forming profile demonstrates higher aerodynamic quality, while the model with the LRN profile has better resistance to flow disruption. The results obtained are of practical importance for optimizing the geometry of small UAVs, increasing their energy efficiency, flight duration and reliability also in conditions of turbulence and wind gusts. They can also be used to verify numerical methods for modeling the flow and developing new design solutions in the field of experimental aerodynamics.

THE USE OF COMPOSITE MATERIALS IN MODERN AIRCRAFT CONSTRUCTION

Mon, 24 Nov 2025 00:00:00 +0200

This article describes the specific features of composite material applications in modern aircraft construction. It presents data on the current state of composite material usage in components and structures and discusses the future prospects for the implementation of advanced materials by leading global aerospace manufacturers. The study highlights the impact of this approach on improving operational efficiency, reducing fuel consumption, noise levels, and the frequency and cost of maintenance. The use of novel materials is expected to sustain the trend toward reducing aircraft weight and to enable further increases in flight speed..

INTEGRATION OF SMART TECHNOLOGIES FOR BUSINESS - ANALYSIS OF ACCOUNTING TRANSACTIONS IN ENTERPRISES

Sergiy Tkachov, Olexander Minai (Author) — Wed, 27 Aug 2025 13:43:19 +0300

Digitalization plays a significant role in the success of the initiative to implement accounting operations, and information management within the company contributes to the development of skills in the field of system and technical design. Effective use of information technologies allows companies to improve their processes and remain competitive in the market. The relevance of implementing SMART technologies at enterprises of the rocket and space industry is growing in the conditions of the modern business environment, which is rapidly changing and requires high adaptability and efficiency. The problems of implementing and implementing business processes at enterprises and the criteria for the effectiveness of their implementation are also considered. With the successful implementation and use of SMART processes, a number of positive effects can be obtained: high business productivity, improving the quality of the working environment and internalmanagement environment, optimizing processes, including the possible redesign of the organizational structure. The implementation of these technologies holds significant potential for improving operational activities and achieving sustainable competitive advantage. However, to date, significant issues regarding the implementation of SMART technologies remain unresolved, which makes the study particularly relevant. It was established that these technologies provide speed, accuracy and optimization of accounting processes, in particular the formation of reports. From the conducted research it was concluded that such dynamic digital transformations will require additional professional training of employees, as well as regulatory regulation at the state level, which is currently imperfect in Ukraine. The scientific novelty of the results obtained in the process of performing the work lies in the improvement of corporate software for business management based on a single ERP database, taking into account the requirements of enterprises in the rocket and space industry by developing new programs that allow accounting with the use of modern information technologies.

The practical sign if icance of the results obtained liesin the development of recommendations that canbeused in the activities of the State Enterprise Yuzhnoye Design Bureau and ot here nterprises.

COMBINING PAAS AND SAAS SERVICES ON A CLOUD COMPUTING PLATFORM FOR NEUROSCIENCE APPLICATION

V Pavlenko, A Ilutsa, V Gidulian (Author) — Wed, 27 Aug 2025 13:40:53 +0300

Web-oriented software tools combining PaaS and SaaS cloud computing services have been developed, which expands the diagnostic capabilities of information technology tools for assessing neurophysiological status and increases the productivity and efficiency of scientific research using eye tracking data. Cloud computing technology has been further developed based on the proposed combination of cloud computing services operating simultaneously according to the principles: platform as a service PaaS (Platform as a Service) and software as a service SaaS (Software as a Service). The developed software tools consist of independent modules and nodes that work in interaction, which allows you to quickly and effectively change and scale its functionality. An important feature of the developed software tools is: undemanding to the hardware on the client side due to cloud computing; combination of PaaS and SaaS cloud computing services, which is implemented thanks to a code editor and a developed interface designer with a code translator that provides communication between the interface and the script code; modular structure of interaction of functional nodes, which allows scaling the software complex. Software tools have the following advantages compared to other similar services: the ability to work effectively in research projects and the educational process both with program code in the Python and Java Script programming languages, and with other data processing software tools loaded onto the platform with existing GUI interfaces; social capabilities and a high level of abstraction.

SENSITIVITY ANALYSIS OF STATISTICAL CRITERIA TO PSEUDORANDOM VARIABLES GENERATION PARAMETERS

Оleksii Klymenko (Author) — Wed, 27 Aug 2025 13:39:00 +0300

This paper examines the influence of the random number generator initialization parameter (seed) on the reliability of statistical conclusions derived from the Kolmogorov-Smirnov and Froncini tests. The object of the study is statistical goodness-of-fit tests, while the subject is the influence of the seed parameter on the outcomes of these tests for different sample sizes. The research aims to determine the role of the seed parameter in shaping statistical conclusions and to develop recommendations for ensuring the robustness of statistical testing results. The methodology is based on a series of numerical experiments with samples of various sizes (n = 10, 20, 30, 40, 100, 200), generated using different seed values ranging from 0 to 100. For each sample, the Kolmogorov-Smirnov and Froncini tests were applied, and the probability of correct statistical decisions was evaluated. The results demonstrate that the Kolmogorov-Smirnov test is sensitive to changes in the seed parameter, particularly for small sample sizes: for n = 10, the probability of a correct decision does not exceed 67%, while for n = 200, this probability increases to 94.5%. In contrast, the Froncini test shows complete independence from the seed parameter, regardless of sample size, confirming its robustness and reliability. Therefore, the Froncini test is recommended for scenarios where the stability of statistical testing outcomes is critical. The scientific novelty of the study lies in quantifying the influence of the random number generator's initialization parameter on the results of widely used statistical criteria and in demonstrating the advantages of the Froncini test for ensuring reliable statistical conclusions. The practical significance of the study is the formulation of recommendations for selecting the minimum necessary sample size and appropriate statistical criteria to enhance the stability of results when working with random data.

DEVELOPMENT OF A SMART FINDER FOR A TELESCOPE

Kostyantyn Serdyuk, Svitlana Klymenko, Yulia Lazareva (Author) — Wed, 27 Aug 2025 13:36:08 +0300

This paper presents an intelligent electronic finder for amateur telescopes, designed to enable accurate and convenient alignment with astronomical objects. The developed system integrates with a mobile application on a smartphone, providing users with real-time coordinates of selected celestial bodies and step-by-step guidance for telescope orientation. The relevance of this work is determined by the limitations of traditional optical finders and the high cost of commercial Go-To systems, which restrict access to astronomy for amateur users. The aim of the research is to develop an affordable and efficient device for telescope alignment with celestial objects, improving the accuracy and convenience of astronomical observations within the amateur community. The research methods include the analysis of existing solutions, development of astronomical calculation algorithms, construction of a prototype based on microcontrollers, inertial sensors, and wireless communication modules, as well as experimental verification of the accuracy of results by comparing them with data from the "Stellarium" software.The solution involves the creation of an integrated system that calculates the coordinates of celestial objects in the horizontal coordinate system (azimuth and altitude) based on the observer's location, current time, and device orientation. The main user interface is implemented as a Telegram bot, which allows users to receive coordinates and control the device. The system significantly simplifies telescope alignment for faint or invisible objects, such as dim stars, planets, galaxies, and nebulae. sThe practical value of this work lies in the development of an accessible tool for precise telescope alignment, promoting the growth of astronomical culture among amateurs. The results confirm the high accuracy of astronomical calculations, which closely match data obtained from "Stellarium." Further development of the project envisions the implementation of automated motor control, creation of a custom mobile application, expansion of compatibility with different telescope models, and improvement of the device housing for outdoor use.

COMPOSITE PIPELINES IN MODERN ROCKETRY

Tamara Man’ko, Valentyn Murashko (Author) — Wed, 27 Aug 2025 13:30:22 +0300

The article provides a comprehensive review of current scientific literature and technological developments in the field of composite linerless cryogenic pipelines intended for application in the aerospace industry. It highlights the growing number of research publications focused on the environmental impact of launch vehicles and presents relevant data illustrating the increase in global launch frequency, as well as the diversification of rocket propellants used in recent years. A comparative analysis of the ecological impact of various propellant types employed in modern launch systems is conducted, with special attention given to the promising performance of cryogenic fuel combinations, particularly liquid oxygen and liquid hydrogen (LOx + LH₂). The classification of cryogenic pipeline and tank constructions is examined, considering both their structural characteristics and material compositions. The advantages and disadvantages of different types, including lined and linerless configurations, are discussed. Special focus is placed on the challenges posed by differential thermal expansion in lined structures, which can compromise structural integrity under cryogenic operating conditions. In contrast, the benefits of linerless designs, such as material homogeneity and potential mass reduction, are emphasized. Studies addressing critical failure modes such as delamination, matrix cracking, and fuel permeation through composite walls are analyzed. The article further explores current manufacturing strategies for filament-wound structures, particularly the use of various mandrel types, including disassemblable, segmented, and dissolvable forms. Advanced fiber placement technologies are evaluated, namely continuous winding, Automated Fiber Placement (AFP), and Automated Tape Laying (ATL). ATL offers high-speed deposition capabilities on simple geometries, while AFP allows for non-geodesic fiber placement and selective reinforcement of stress-prone zones, albeit with lower productivity. The limitations and advantages of both techniques are discussed in the context of aerospace requirements. Finally, the article presents examples of successful developments in linerless composite cryogenic systems achieved by private companies, governmental research centers, and intergovernmental programs. Special attention is given to Ukrainian advancements in this field, including solutions developed at KB Pivdenne.

INCREASING THE EFFECTIVENESS OF ULTRASONIC NON-DESTRUCTIVE TESTING OF COMPLEX TECHNICAL OBJECTS

Pavlo Sazonov, Svitlana Klymenko (Author) — Wed, 27 Aug 2025 13:23:51 +0300

Ensuring the safety and quality of high-tech engineering structures is one of the key challenges in modern industry. The presence of internal defects or damage in materials of potentially hazardous structures can lead to severe accidents with significant environmental and social consequences. Similarly, defects in components of complex consumer products—many of which consist of tens of thousands of parts—can result in substantial warranty service costs and damage the manufacturer’s reputation. As a result, despite the high cost, non-destructive testing (NDT) is becoming an increasingly essential tool for ensuring that structures comply with operational requirements. Among the various NDT techniques, ultrasonic testing (UT) is gaining broader recognition and application due to its balance of advantages and limitations. Ultrasonic non-destructive testing is widely used to detect internal defects such as cracks, voids, and delaminations. However, the reliability of UT depends on several factors, including the type of reference reflector used for equipment calibration, its geometrical parameters, and the acoustic properties of the material. This article discusses the advantages and limitations of current ultrasonic testing methods and presents analytical models for different types of reflectors that improve measurement accuracy.Most conventional ultrasonic testing techniques, as well as the majority of ultrasonic inspection equipment, rely—directly or indirectly—on amplitude-based methods for defect sizing in inspected objects. Nevertheless, practical experience in the manufacturing, verification, certification, and testing of ultrasonic calibration and reference specimens shows significant variation in signal amplitudes from identical reflectors within different specimen sets, despite high-precision fabrication.Attempts to compensate for this issue through further increases in manufacturing accuracy of reference samples, stricter requirements for UT results, or similar corrective strategies significantly increase costs, hinder the advancement of NDT technologies, and slow technical progress overall.This paper proposes a foundation for justified methods aimed at reducing signal amplitude discrepancies in ultrasonic calibration and reference blocks, thereby improving the overall reliability and efficiency of ultrasonic non-destructive testing without excessive cost increases.

ELECTROMAGNETIC RADIATION. CLASSIFICATION AND ANALYSIS OF INTERACTION WITH THE ENVIRONMENT

Serhii Bozhko, Valery Leman (Author) — Wed, 27 Aug 2025 13:22:06 +0300

The article discusses issues related to the nature and characteristics of electromagnetic radiation (EMR). The article consists of 3 parts. The first part presents the classification by wavelength and the main key stages in the development of the theory of electromagnetic waves. The main physical characteristics of different types of radiation and their properties are considered. The second part is devoted to the effects that occur when radiation interacts with substances. The indicators and laws according to which radiation changes when passing through a certain layer of material are considered, the areas of practical application of these phenomena are given. The third part considers the anomalous effects of the interaction of radiation with matter, modern discoveries and achievements in this area, technologies for obtaining new functional materials and prospects for the development of research in this direction. The modern environment is saturated with electromagnetic fields and electromagnetic radiation, which are widely used for communication, information transmission and in many other processes that not only benefit humanity, but also have a number of harmful and dangerous factors, which requires the development of certain means of protection of both biological and technical objects from such radiation. Therefore, an attempt is made to analyze and systematize the currently existing information about electromagnetic radiation, its harmful effect on electronic equipment, means of communication, biological objects in order to determine the ways of developing protective materials and technologies for their production.

STUDY OF THE INFLUENCE OF THE STRUCTURE OF PBF-LB/M ADDITIVELY MANUFACTURED 1.4859 ALLOY ON ITS PROPERTIES

Tatyana Myronova, Sergey Bushtruk (Author) — Wed, 27 Aug 2025 13:20:16 +0300

Materials used in aerospace for operation under high-temperature and aggressive environmental conditions must exhibit enhanced corrosion resistance as well as good manufacturability. One significant advantage of the laser powder bed fusion of metals (PBF-LB/M) additive technology is the ability to fabricate enclosed thin-walled structural elements with wall thicknesses as low as 0.3 mm, corresponding to the specifications of highly efficient heat exchangers or capillary tubes produced by conventional methods. The use of heat-resistant, corrosion-resistant alloys with minimally sufficient nickel and chromium content is more appropriate for this type of application. The PBF-LB/M process, characterized by gradual ultrafast melting and crystallization of metal microvolumes, as well as repeated thermal cycling within the sub-solidus temperature range, enables the formation of fine-grained microstructures with unique properties. These properties may exceed those of chemically identical materials produced by traditional manufacturing technologies such as casting or rolling. A considerable body of scientific work has been devoted to studying the properties of components fabricated by PBF-LB/M, taking into account the structural factor. However, the rapid expansion of the range of materials available for the PBF-LB/M process without concurrent qualification and standardization leads to a lack of comprehensive data on material properties, particularly regarding strength and corrosion resistance, as well as their changes during subsequent processing and operation. This study investigates the microstructure, mechanical properties following uniaxial tensile testing, and resistance to intergranular corrosion of components made of alloy 1.4859 (Fe-32Ni-20Cr-1Nb) produced via the PBF-LB/M additive manufacturing technology. It was established that enhanced strength parameters are attributed, firstly, to the structural characteristics of the material, including grain size and orientation, state of grain boundaries, and the presence of precipitates of secondary phases, secondly, to the direction (plane) of mechanical testing, and thirdly, to the presence of internal structural defects. In the as-built condition (after PBF-LB/M fabrication), the strength characteristics exceed the requirements for cast components made from this alloy, as well as those for rolled products from Incoloy 800 and KhN32Т alloys. The study further demonstrated that heat treatment at 1150ºC enhances resistance to intergranular corrosion.

ACTIVE PROTECTION SYSTEMS AGAINST PRECISION WEAPONS AND THEIR PROSPECTS

Mykola Bondarenko, Volodymyr Gabrinets, Mykhailo Vorobei (Author) — Wed, 27 Aug 2025 00:00:00 +0300

The protection of military equipment from precision-guided munitions (PGMs) is one of the key challenges for modern armies. As offensive technologies advance, traditional armor has become insufficient. Consequently, active defense systems, particularly the "hard kill" concept, are gaining increasing importance.This article examines various active protection methods used to neutralize incoming threats before they reach their target. Special attention is given to air defense, a crucial component in countering precision-guided weapons such as missiles and drones. The study provides an in-depth analysis of radar systems like the AN/TPS-43E and AN/TPS-75, which play a vital role in detecting aerial threats. Additionally, the use of fighter aircraft equipped with air-to-air missiles is explored, demonstrating their effectiveness in eliminating airborne targets.A separate section is dedicated to surface-to-air missile systems, particularly the Tor-M1 system, which effectively neutralizes cruise missiles, drones, and aircraft. The effectiveness of close-range gun-based defense systems, such as the Mark 15 Phalanx CIWS, is also analyzed, highlighting their role in protecting naval vessels and ground-based installations.Furthermore, the article discusses the development prospects of active protection systems for armored vehicles, with a focus on the Ukrainian Zaslon APS. The potential application of electromagnetic pulses (EMP) to disable enemy munitions' electronics is examined, along with the viability of laser weapons in neutralizing aerial threats.This study provides an overview of modern active defense technologies and evaluates their effectiveness in military conflicts, emphasizing the necessity for further research and development in this field.Moreover, it considers the future challenges of countering evolving threats and the need for continuous innovation to stay ahead of adversaries in terms of defense capabilities.

PROSPECTS FOR THE USE OF ROCKET FUEL BASED ON KEROSENE-HYDROGEN PEROXIDE PROPELLANT

Yurii Minakov, Andrey Pavlenko, Yurii Mitikov (Author) — Tue, 26 Aug 2025 22:08:27 +0300

Today, the most common oxidizer in the world rocket and space technology is liquid oxygen. Its use dates back to the V-2. Extensive experience has been accumulated with it. It would seem that everything is possible with it. However, this is not entirely true. Currently, quite intensive searches are being conducted for a substitute for oxygen. The reasons for these searches in modern rocket engines are analysed and systematized. The main disadvantages of oxygen, which have long been tried to be eliminated, are listed. They significantly complicate the propulsion system and the launch vehicle as a whole. Among them are the fuel component ignition systems (especially for multiple engine starts), cooling of pumps, refuelling of tanks, combating the geyser effect (for second stages of launch vehicles), thermal insulation of the bottoms, temperature control of compartments, compensation for thermal expansion, etc. In oxygen engines with kerosene fuel, the design of the combustion chamber also becomes more complicated. In this case, there is a need for barrier and curtain cooling of the chamber in a bronze insert in the critical section. The renaissance of such an oxidizer as hydrogen peroxide is shown and analysed. At one time, liquid rocket engines in Great Britain and the Soviet Union were interested in it. Today, it is successfully used in the Scottish company Skyrora, the American Ursa Major. For the first time, the main positive properties of peroxide as a rocket oxidizer in relation to liquid rocket engines and launch vehicles in general are systematized. Its advantages are shown. The state of aggregation of hydrogenperoxideis a non-boiling liquida to perating temperature. There is noneed for cooling the pumpor the make-upmode. There are alsono conditions for water hammer duringre fueling. Onhydrogenperoxide, the gasgenerator, nozzleapparatus and turbine are free of soot. This significantly simplifies the reuse of the PH stage. Onhydrogenperoxide, a recordthrottlingdepthisachieved – upto 20 times.

METHODS FOR QUANTITATIVE ANALYSIS OF THE STRUCTURE OF MATERIALS. OVERVIEW

Vladyslav Tymoshenko, Anatolii Sanin (Author) — Tue, 26 Aug 2025 22:06:15 +0300

Purpose. The purpose of this study is to evaluate and compare quantitative methods for analyzing the structure of materials, with including cases such as non-grain phases. Design / Method / Approach. The work examines six primary approaches for analyzing the structure of materials: equivalent diameter analysis, linear intercept method, random intercept method, fractal analysis, planimetry, and point count techniques. These methods are tested on microstructures with various phases including carbides. Method-specific advantages, implementation difficulties, and statistical robustness are addressed. Findings. Each method provides specific benefits. Equivalent diameter simplifies irregular inclusions, intercept methods ensure statistical validity, and fractal analysis reveals geometric complexity. Planimetry and point count techniques deliver quantitative metrics for grain size and phase composition. Their combined use allows comprehensive evaluation of structural complexity, especially in materials with heterogeneous phase distributions, and is critical for advanced quality control or microstructural design. Theoretical Implications. The study contributes to the understanding of statistical and geometrical techniques applicable to microstructural analysis beyond standard grain characterization. Practical Implications. The results can be used to select a method for analyzing structural materials, in particular those containing carbide inclusions and other uneven phases. Originality / Value. The article offers a structured comparison of practical quantitative methods applicable to advanced material characterization tasks. Research Limitations / Future Research. The analysis was limited to 2D cross-sections. Future work should include 3D reconstruction and investigation into automation instruments for choosing the most optimal analyse method.

TECHNOLOGICAL ASSURANCE OF THE QUALITY OF PRODUCTS BY NON-TRADITIONAL METHODS

Maxym Nakhod, Ivan Karpovych (Author) — Tue, 26 Aug 2025 22:04:25 +0300

An extensive body of literature suggests that the vast majority of the energy used for metal turning is converted into heat. In the case of employment of traditional turning method, up to 98% of energy can be converted to heat and, as such, wasted. It's important to mention that not only does the energy to heat conversion decrease the efficiency of the metal processing but also it reduces the lifespan of the instrument as well as worsens final detail top layer quality. To reduce the amount of heat, several non-traditional processing methods were invented. Some of those are: extremely high-speed cutting, rotational cutting and sliding cutting. On top of lowering heat production, some of those methods may improve top layer quality of the detail. To better understand involved processes, in this article we analyzed different aspects affecting energy intensity of cutting process. Also, an analytical formula to show the relation of conditional cutting stress to the cutting coefficient was provided. Based on this dependency, forementioned non-traditional methods were examined to identify the most promising one to reduce the energy intensity of the cutting process and to improve the top layer quality of the detail without necessity to apply additional operations. For each method, the advantages and limitations were presented. In the final part of this article, the most promising non-traditional method was selected for further investigation and introduction into the manufacturing industry.

DETERMINATION OF DIMENSIONS OF TECHNOLOGICAL EQUIPMENT FOR THE PRODUCTION OF PRESSED BLANKETS OF THE “PLATE” TYPE FROM ALUMINUM ALLOY POWDER

O. Bondarenko, A. Sanin (Author) — Tue, 26 Aug 2025 22:00:22 +0300

Machine parts, including those for aviation and rocket and space technology, made from aluminum alloy powders, have advantages over similar parts made from semi-finished products and blanks obtained by the “casting-pressure treatment” method in terms of strength, heat resistance, and corrosion resistance. This is especially true for parts made from powders obtained by dispersing a jet of melt with a high-pressure water jet.ncreasing the strength, heat resistance and corrosion resistance of aluminum alloy parts contributes to improving the tactical, technical and economic characteristics of rocket, space and aviation equipment. For the manufacture of rocket, space and aviation equipment parts, large-sized semi-finished products and blanks are required, such as sheets, plates, pressed profiles with various cross-sectional shapes. It is noted that for the manufacture of such semi-finished products, large-sized blanks and, accordingly, methods of their production are required. The article analyzes known methods of producing billets from aluminum alloy powders obtained by dispersing melts with water. It is determined that the method of pressing powder and porous billets in one direction has significant limitations on the cross-sectional dimensions. It is established that for the known method of pressing powders and porous billets in mutually perpendicular directions there is no dependence between the dimensions of the billet and the height of the working space of the press. The article establishes the dependence between the height of the working space of the presses in the manufacture of prismatic blanks from aluminum alloy powders by pressing the powder and the porous blank in mutually perpendicular directions and the dimensions of the blanks. It is established that the limiting factor that limits the dimensions of the blanks is the height of the working space of the press intended for pressing the porous blank to the theoretical density of the alloy.t hasbeen established that at comparable values of the pressure of pressing a porousworkpiece, the methods of pressing powder and porous work piecein perpendicular directions and in one direction provide comparable dimensions of prismatic workpieces. It hasbeen established that when pressing

RETROSPECTIVE ANALYSIS OF EXISTING TRACTION VECTOR CONTROL SCHEMES

Georgy Nazarenko, Oleksandr Ponomaryov, Stanislav Bilogurov (Author) — Tue, 26 Aug 2025 21:57:51 +0300

When choosing an engine with control elements for the upper stages, in some cases, it is optimal to use a liquid rocket engine without afterburning with steering nozzles that use high-temperature gas from a turbopump unit. Therefore, when choosing the optimals cheme of a liquid rocket engine, it is necessary to analyze a setof a number of factors, suchas: the magnitude of the required controlef forts, and the dimensions of the product. All these factors significantly affect the energy characteristics of a liquid rocket engine. After conducting a retrospective analysis of existing thrust vector controls chemes for liquid rocket engines and obtaining moments that control the thrust vector, it was found that the use of gas-dynamic methods of thrust vector control leads to lossesin specific impulse, a significantin crease in the dimensions and massof the liquid rocket engineor the propulsion systemas a whole. Currently, various schemes for obtaining moments that control the oscillation of a liquid rocket engine are widelyused. Each of the three oscillations chemes described abovehasits advantage sanddis advantages, and sowesee that the maindis advantage of the scheme for swinging a liquid rocket engine by the nozzle head of the chamberis the complexity of manufacturing the chamber elements, the high temperatures of which will be exposed to the elements of the swingas sembly. Thea dvantage of the second sevenis that a relatively small massis oscillating, but the disadvantageis the complexity of manufacturing the bellowsassembly, which is installed on the chamber head. The scheme for swinging a liquid rocket engine by the nozzle head of the chamberin a sense combines the two schemes described above – we swing the entire liquid rocket engine, and the flexible elements are located along the low-pressure line, while the swing axis canbelocated closer to the center of mass, which will reduce theef fort required for the drives.

THE METHOD OF INFLATING THE FUEL TANK OF THE LIQUID PROPULSION SYSTEM OF THE LAUNCH VEHICLE

Oleksandr Ponomarov, Maksym Sedchenko, Heorhii Nazarenko (Author) — Sat, 23 Aug 2025 12:40:39 +0300

Inflating systems (IS) of fuel tanks of rocket launchers (RL) are designed to ensure the necessary pressures of fuel components at the entrances to engines and intake devices (for their continuous operation). They are also needed to create the necessary gas pressure levels in thin-walled fuel tanks for their stability in the active section of the launch vehicle's flight path. The inflation process consists, as a rule, of two stages - pre-launch inflation (PI) and main (flight) inflation (MI). The PI system is intended only to ensure the required pressure of the fuel components at the entrance to the pumps using the pressure in the tanks at the start-up stage of the RC. For the first stages of the RC, and sometimes the second, they work on the ground before the very start of the RC. The MI system is designed to ensure the stability of the thin-walled structure of the tank, the cavitation-free operation of the intake device and the uninterrupted operation of the RC pumps during its operation in flight. The invention presented in the article can significantly improve the process of inflating fuel tanks of liquid propulsion units (RC), its main tasks are to simplify the design and increase reliability, reduce mass and reduce the cost of the system that implements it. This is solved by the fact that, according to the invention, at the stage of pre-launch inflation, thermal energy is injected into the free volume of the fuel tank with the help of electric current from the starting position, the upper bottom of the tank is shielded from the heat flow, after the launch of the launch vehicle, thermal energy is injected into the tank by with the help of an electric current from the side of the launch vehicle, after which hot inflation gas is injected into the tank along its longitudinal axis.

STUDY OF THE INFLUENCE OF THE ENVIRONMENT CHARACTERISTICS OF THE PULSE DETONATION ENGINE

Oleksandr Aksonov, Oleksandr Zolotko, Vitalii Stolyarchuk, Denis Mudrov (Author) — Sat, 23 Aug 2025 00:00:00 +0300

In a pulse detonation engine (PDE), the flow parameters change over a wide range. In this case, the ambient pressure may exceed the fuel mixture supply pressure. The goal of the work is to determine the features of the influence of the environment on the pulse characteristics of the detonation engine. The subject of the study is the influence of environmental factors on the processes occurring in the combustion chamber of the pulse detonation engine. The main research method used in the work is the method of numerical simulation using CFD technologies. The main influencing factors are the pressure and density of the atmosphere with which the detonation products interact during their outflow from the detonation chamber. An analysis of the influence of the determining factors on the value of the specific impulse was carried out. The following results were obtained. In the event that the ambient pressure exceeds the fuel supply pressure in the detonation chamber, the shock wave at the detonation front interacts with the atmospheric flow entering the detonation chamber. The interaction is accompanied by a pressure jump in the flow part of the chamber reaching the thrust wall. The increase in pressure leads to an increase in the specific impulse due to an increase in the time of action of detonation products on the thrust wall of the engine chamber. When the detonation wave front collides with a denser substance, a partial reflection of the shock wave is observed, which causes an additional increase in pressure on the thrust wall. Conclusions. In the pulse detonation engine chamber, in the presence of backpressure from the environment, there is a partial compensation of the loss of the specific impulse associated with the formation of a pressure jump behind the detonation wave front. In the PDE operating mode with partial reflection of the detonation wave from a denser environment, the increase in the specific impulse reaches 30% compared to operating conditions without front reflection.

Peculiarities of creation and use of transformable space boom structures

Vladyslav Shamakhanov, Serhii Khoroshylov (Author) — Tue, 18 Mar 2025 00:00:00 +0200

Transformable space structures (TSS) have found application in space technology. This is due to the fact that they provide the possibility of dense packing of large spatial structures under the fairing of a launch vehicle. Due to the wide variety of tasks performed in space, the variety of spacecraft is also growing, as well as the scope of their application - from space manipulators to large antennas. These structures are a very important element of the respective space systems, as the success of space missions depends on their reliability. The development of such structures requires a thorough analysis of their decomposition dynamics, strength and structural stability, as these issues can be critical for space missions. There are cases of non-degradation of certain space structures, as well as cases of their destruction in space. Due to the complexity of conducting full-scale experiments, special attention is paid to computer modelling of the CSC. Particular attention is also paid to strength calculations and the selection of appropriate materials to preliminarily determine the maximum loads that the structure can withstand. This once again emphasises the relevance of spacecraft research. This article provides an overview of deployable space boom structures, including booms and manipulators. The key differences between different approaches to solving the main tasks of the study of deployable booms are highlighted. Several of the most common types of deployable structures are highlighted, and their differences, advantages and disadvantages are discussed.

Review of polymer fused deposition material additive manufacturing technology for aerospace application

Vladyslav Danylenko, Volodymyr Lipovskyi (Author) — Tue, 18 Mar 2025 00:00:00 +0200

This review article explores the polymer-based fused deposition modeling (FDM) role in aerospace additive manufacturing. It focuses on analyzing thermoplastics like ABS, PEEK, and PEI. Composites such as carbon fiber-reinforced PEEK are also examined. The research uses scientific literature and industrial examples. Real cases highlight FDM’s ability to create lightweight, complex designs. The technology also reduces material waste and costs. Semi-crystalline polymers like PEEK show high strength-to-weight ratios. Their oriented molecular chains improve performance. Amorphous polymers, such as ABS, are cheaper but less thermally stable. Composites bridge the gap between polymers and metals. Carbon fiber-reinforced PEEK offers tensile strengths up to 100 MPa and withstands temperatures above 260°C without adding density. The study links polymer microstructure to function. Crystalline regions enhance strength. Amorphous areas limit thermal resistance. Ashby plots compare tensile strength, density, and cost. These charts guide material selection. Practical insights include guidelines for material selection. ABS suits prototypes and non-critical parts like UAV brackets. PEEK and PEI are better for high-stress uses, such as outer panels. Printed parts often have directional weakness (anisotropy). Long-term durability data under extreme conditions is scarce. Examples include UV exposure and cyclic loading. Performance varies across FDM printers. Standardization and certification remain challenges for critical systems. Future work should focus on high-temperature polymers for hypersonic flight. Multi-material printing could create graded parts, like heat-resistant exteriors with flexible interiors. Bio-sourced or recyclable filaments would support sustainability. AI-driven optimization may improve defect detection. Hybrid methods, like combining FDM with CNC machining, could boost precision. The research provides a roadmap to address technical and regulatory barriers. It positions FDM as a sustainable solution for aerospace. Balancing performance, cost, and environmental goals is key.

Experimental study of the strength characteristics of composite fiber reinforced parts

Maksym Sirenko, Olena Karpovych (Author) — Tue, 18 Mar 2025 00:00:00 +0200

Parts and products obtained by additive manufacturing methods are increasingly gaining popularity and use. These are not only household parts and decorative products, but also parts for mechanical engineering, machine tool building, aviation and rocket and space industries. With the increasing spread of such pieces, operational requirements for them are also increasing, which encourages researchers and manufacturers of equipment and materials to improve the capabilities and characteristics of end products. One of the most popular and widespread types of additive manufacturing - FDM 3D printing, also has a need and potential for improving the properties of final products. One of the types of improving properties is the use of reinforcement, filling polymers with composite fibers or granules, powders. The main method of reinforcement is filling the original plastic with composite fibers or adding fiber to the plastic base during printing in various ways. Such reinforcement methods already exist in the market and in industry, but they have drawbacks. One of these shortcomings is the failure to ensure the continuity or uniformity of the reinforcement, which leads to the formation of zones of reduced strength and stress localizers in the finished part. Therefore, the purpose of this study is to present a reinforcement method that preserves the layer-by-layer and interlayer continuity of the reinforcement fiber, does not allow the formation of weakening zones along the reinforcement axis of the part. The reinforcement method was developed, the technological equipment necessary for its implementation was developed and manufactured, specimens for tensile tests were manufactured and tests were conducted. The features and testing methodology were also described, the parameters of the specimens and their manufacturing modes were given. Experimental results were obtained, compared with the results for unreinforced specimens. The developed reinforcement method achieves an almost twofold improvement in the physical and mechanical properties of the part, proving its workability.

Processing of various alloys with multifunctional modifiers based on aluminum chips

Yurii Tkachov (Author) — Tue, 18 Mar 2025 00:00:00 +0200

Improving the mechanical properties of alloys without significantly compromising their ductility is one of the key challenges in modern metallurgy. An important research direction is the enhancement of material strength while maintaining processability and durability. A promising approach to achieving this goal is the use of multifunctional modifiers based on pressed aluminum chips. These modifiers significantly influence the processes of deoxidation, microalloying, and modification of the metal, thereby improving its mechanical properties. This study presents the results of experimental research conducted at the metallurgical enterprise JSC “Dnipro Metallurgical Plant.” The mechanism of action of briquetted aluminum chips in molten metal and their effect on the removal of non-metallic inclusions were investigated. Particular attention was paid to changes in chemical composition, gas environment, mechanical properties, and microstructure of the treated alloys. The obtained results demonstrated that the use of such modifiers reduces the content of oxygen and hydrogen inclusions, thereby improving metal purity. The application of aluminum chips as a modifier not only enhances alloy quality but also reduces the cost of expensive primary alloying materials. This makes the technology both economically viable and environmentally sustainable. The study confirmed that the implementation of this technology increases production efficiency by reducing energy consumption and minimizing waste generation. A comparative analysis of different modification methods confirmed the advantages of using briquetted aluminum chips over traditional alloying and modification techniques. Optimal parameters for the industrial application of such modifiers were identified. In addition to technical aspects, the study also examines the economic feasibility and environmental benefits of utilizing briquetted aluminum waste in metallurgical processes. The use of secondary aluminum raw materials reduces production costs and promotes the efficient use of resources, aligning with modern trends in sustainable industrial development. Thus, the research findings confirm the feasibility of using multifunctional modifiers based on aluminum chips to improve the mechanical properties of alloys. The obtained data can be applied in the development of new technological processes in modern metallurgy, aimed at enhancing the quality and cost-effectiveness of metal production.

Simulation of the movement of small rocket in vertical flight

Roman Harkusha, Anatolii Kulabukhov (Author) — Tue, 18 Mar 2025 00:00:00 +0200

To develop rocket and space technologies, the country must have its own spaceports, which must provide safe launch conditions for launch vehicles. Ukraine developed its rocket and space technologies using the Baikonur and Sea Launch cosmodromes. Currently, there are no such opportunities in Ukraine. In addition, one of the promising directions is the creation of cheap small RNs for launching small spacecraft into low orbits. One of the ways to work out such technologies in the absence of spaceports is to launch created small RNs vertically. The object of research is the process of rocket motion during vertical flight. The subject of research is the influence of the parameters of the Earth's rotation and air speed on the determination of the fall zones of RH with vertical flight. The purpose of the work is the development of a mathematical model and simulation of the movement of small rockets in vertical flight. The solution of the problem is based on the following assumptions: the movement of the RN occurs in the inertial coordinate system using the inertial control system; Earth is a layer with a radius Rz=6370 km and a uniform density; in the zone of vertical flight, the Earth is flat; horizontally, the aerodynamic force at low speed does not affect the movement of the rocket; the Y axis of the selected coordinate system is directed vertically at the starting point; axis X is directed horizontally at the starting point and in the direction of rotation of the Earth; along the X axis, the RN receives an initial speed determined by the rotation of the Earth at the starting latitude. Methodological support has been developed, which allows you to study the process of movement of small rockets during vertical flight with an inertial control system and to determine the influence of air velocity and Earth's rotation speed on the fall zones depending on the characteristics of the rocket.

Segments with functions of observation of orbital objects and communication as part of an integrated satellite system

Tetiana Labutkina, Oleksandr Akinshev (Author) — Tue, 18 Mar 2025 00:00:00 +0200

The topic of the article is at the junction of three scientific and practical areas, which are important components in the development of space activities: maintaining up-to-date information about a set of objects in near-Earth orbits; application of network information technologies in space; creation of satellite systems based on the principle of multifunctionality, implementation of integration of functions within one satellite system, combination of satellite systems for different purposes into a single functionally integrated system. The article proposes an approach to the construction of different-height segments with communication functions and observation of orbital objects that are part of a functionally integrated satellite system on different-height orbital groups. In this case, the communication function is presented as a basic-auxiliary one for the implementation of the target function of observation of orbital objects (as a “platform” function of the system), and as a target function of the system (which is one of the target functions of the system). The article is divided into two parts. In the first part of the article, published in [1], two conceptual solutions are proposed for constructing orbital segments of an integrated satellite system, in which the function of observing orbital objects is implemented. According to the first concept, the observation segment of orbital objects contains only observer spacecraft that implement communication and observation functions. According to the second concept, the observation segment also includes communication spacecraft that relieve observer spacecraft from establishing lateral connections in one segment and from implementing intersegment connections. The second part of the article is devoted to the development of approaches to comparing the characteristics of the system's functioning under different conceptual design solutions. In the system structure, elementary structural units of the same type (communication groups) are distinguished, which ensure the communication of the functional units of the system, represented by observer spacecraft or functional pairs of observer spacecraft. The system's functioning indicators calculated for the communication group are acceptable for the characteristics of all groups of this type in the system and characterize the system as a whole. The results of numerical calculations are obtained, which represent the results of a comparative analysis of the application of the two proposed conceptual solutions. This publication presents the second part of the article.

Algorithms for calculating the angular deviation of an optical data processing system

Artem Dymchenko, Svitlana Klymenko (Author) — Tue, 18 Mar 2025 00:00:00 +0200

The article analyzes the algorithms for processing matrix types of information flows obtained from the developed module of spatial orientation and manipulation for the product of the project "Student Rocket "Rocketry Agency" and identifies the main research prospects for its use and development. The prospects for the development of the research direction of the development of algorithms for calculating matrix-type data are revealed in the use of simple linear-cyclic functions based on a limited number of mathematical operations of the arithmetic-logical core of the microprocessor. The main obstacle to the use of mathematical matrix operations based on 8-bit and 32-bit controllers is the impossibility of organizing a multi-current (parallel) process of processing mathematical data in real time, as well as the inability to provide sufficiently large amounts of dynamic memory for storing calculated and primary data. The main feature of microprocessor devices is linear-cyclic sequential execution of operations in a fixed time clock mode, in which a predetermined number of program cycles is allocated for each operation. Knowing the number of cycles for performing mathematical operations, it is possible to accurately determine the time of operations, which will allow you to optimize the program as much as possible to ensure the maximum possible performance of the system. The following approach is used as the main methods for solving the problem (matrix data processing): search and selection of the minimum possible amount of useful data for the further implementation of linear mathematical equations; conversion and optimization of matrix-type data and their conversion into algebraic equations; the use of linear-cyclic algorithms for data calculation for the further implementation of the selected mathematical model; the use of the minimum possible number of variables to save the results of data processing, or the use of one variable in the form of accumulation of identical values for the further process of arithmetic averaging of the calculation result; the use of a sufficient number of data averaging algorithms to ensure the specified accuracy of calculations. Taking into account the physical features of the flight of the D-150 and D-300 launch vehicles, special attention is paid to the speed of processing mathematical calculations to ensure the maximum possible speed of the mechanical controls of the system and maximize the flight altitude and stabilize the operating trajectory. The main principle in the implementation of the system for calculating the angular deviation of the system was the combination of gradient functions for processing the magnitude of the displacement vector of monochrome images at the level of pixel binary values of an object of a given shape in combination with the functions of spatial geometry of the plane and point with an unambiguously defined value of the vector of distance from the center of rotation, which is controlled by an optical sensor of the appropriate purpose.

Modern classification of rocket engine fuel tanks inflation systems

Yurii Mitikov, Vladyslav Leshchenko (Author) — Mon, 23 Dec 2024 00:00:00 +0200

Fuel tank in flation systems of rocket propulsion systems are the most science-intensive and expensive parts of the RN after liquid rocket engines. For the first time, an attempt was made to create a modern classification of fuel tank inflation systems of rocket propulsion systems. The classification was carried out according to the main characteristics. They were also identified for the first time. Four features were identified. This is the principle of ensuring and maintaining the required gas pressure in the tank. It is shown for the first time that there can be at least two of them. The first way is the introduction of thermal energy into the free volume of the tank (with the help of electrical energy). The second is the traditional one, by introducing the working body of inflation. The second sign is the temperature of the inflation fluid at the entrance to the tank. The entire known range of possible gas temperatures at the entrance to the tanks, from super-cold (realized) to super-hot (theoretically justified), was considered. The third feature is methods of obtaining (storing) the working body of the inflator on board the launch vehicles. It is this feature that primarily characterizes the design features of the systems, their characteristics, limitations on the main parameters, logistics, the architecture of the launch vehicles and the cosmodrome. The fourth sign is the type of inflation gas. These are both pure gases - nitrogen, oxygen, helium, and various mixtures - combustion products of liquid and solid fuel gas generators, compressed air, vapors of nitrous oxide, methane, decomposition products of hydrogen peroxide, unsymmetrical demethyl hydrazine, ammonia. They also significantly affect the weight balance, the design of the inflation systems, the intensity and directionality of intra-tank processes, the architecture and complexity of the RN, cosmodrome and logistics. The systems that work before the start on the ground and in the active part of the flight are considered. Examples of the use of the most used supercharging systems in combination with engine operation schemes are given. The strengths and weaknesses of the considered inflation systems, rational areas of their application are emphasized. Ways of further improvement of inflation systems are planned. This is, first of all, the optimization of these systems for multiple use of the first stages of launch vehicles.

Verification of methodological approaches to evaluating the characteristics of compositesolid rocket propellants

Mon, 23 Dec 2024 00:00:00 +0200

The subject of study in the article are the processes of theoretical evaluation of the main parameters of composite solid rocket propellants. The purpose is to verify the existing methods for estimating the parameters of solid mixed rocket fuels by comparing these results with experimental data obtained during bench fire tests of real rocket engines with a thrust of up to 5000 N.The assignments: to conduct a search and analysis of methodical approaches to the estimation of parameters of solid mixed rocket fuels, including the use of software that helps to perform it; to compare the results of calculations using the selected software and analytical expressions of gas flow dynamics; to explorethe factor influence of condensed phase to main parameters of propellants; to carry out bench testing of a series of solid rocket motors with a thrust of up to 5000 N while fixing its main parameters; to process the data collected during bench tests;to compare the results of bench testing with data taken from other theoretical methods.The obtainedresults. The comparison of the insurance parameters of compositesolidrocketpropellants, obtained with the help of ProPEP 3 software and analytical deposits of gas flow dynamics, shows similar results.There are two variants of propellants for examination at a significant stage of metallization by aluminum powder.Considering this, as well as the small size of solid fuel rocket engines that were tested during fire tests, the influence of the factor of the presence of the condensed phase in the combustion products is largely manifested.The existing method of calculating the parameters of the two-phase gas flow gives results that are largely confirmed by experimental data obtained during bench tests.For the considered solid rocket motors, it is shown that an increase in the degree of metallization, despite the opposite results obtained from the assumption of the behavior of combustion products as an ideal gas, does not lead to a real increase in specific thrust and is accompanied by an increase in the temperature inside the combustion chamber.Conclusions. It was established that the relative percentage deviation of the value of the specific impulse between experimental and calculated data is less than 3%, which allows us to talk about a high rate of coincidence between the considered technique and experimental data for engines of the selected size and thrust value.

Experimental investigation of surface roughness of liquid rocket engines parts manufactured with additive technologies

Mon, 23 Dec 2024 00:00:00 +0200

Modern development of additive manufacturing forms tasks of re-engineering of the existing design solutions and implementation of 3D printing technologies for new parts manufacturing. Nowadays, there is a large number of the process categories of “metal” additive manufacturing every of which is based on different principles and bears individual features. One of the most widely used process is a “single step” Powder Bed Fusion during which building parts are produced for a single operation. A focused laser beam is utilized as a heat source so that words collocation Laser Powder Bed Fusion (L-PBF) is used to address the process. L-PBF process is applied in the most different fields: aviation, space, biotechnical and other industries. One of the most appealing aerospace applications for production of complex parts of the liquid propellant rocket engines. A wide nomenclature of the available powder materials and relatively low requirements for technical level of equipment of the production site may be used for reasoning of the phenomena of growing popularity. One of the features of the L-PBF process is relatively high roughness of the produced surfaces which should be considered while designing of hydraulic tracts. There is a “stair-step effect” which contributes to roughness increase due to layer-based process which depends heavily on surface orientation during the building of the part, its location on the building plate, etc. Surface roughness of the L-PBF-manufactured parts is the subject of the experimental investigation of this work. The effect of the roughness change according to the part orientation and building direction is experimentally investigated on the test plates and inner surfaces of the swirl injectors specimens. All investigated specimens were built from Inconel 718. Four variants of the design types of swirl injectors specimens were investigated. The dependency of the roughness parameters versus inclination angle of the surface was obtained after the carried out analysis of the experimental data. Harmonic trigonometric dependencies are proposed for the roughness prediction. The proposed model accuracy is verified using Fischer criteria with =0.05.

Influence of modification with multifunctional modifiers on the mechanical characteristics of wheel steels

Serhii Polishko (Author) — Mon, 23 Dec 2024 00:00:00 +0200

The article deals withthe complex impact of aluminum and titanium on reducing the content of harmful impurities, such as sulfur and phosphorus, and on improving the mechanical properties of KP-T wheel steel produced at PJSC "INTERPIPE NTZ." It has been proven that under the influence of modification, the concentration of harmful impurities decreases significantly more than in serial metal, which improves the structure and increases the level of mechanical characteristics of the steel. Special attention is given to the complex action of multifunctional modifiers containing elements that help achieve a high uniformity of the chemical composition and improve the operational characteristics of the steel. The effect of modification on the formation of submicroscopic compounds in the liquid melt was studied, improving the stability of the chemical composition. The study results indicate an increase in the strength limit and improved plasticity of the steel after modification, allowing an extended service life of the products. It was found that aluminum and titanium promote volumetric crystallization, ensuring a uniform distribution of non-metallic inclusions in the metal. This results in a significant increase in mechanical properties, such as yield strength and impact toughness. Modified KP-T steel has shown higher wear and corrosion resistance, making it more attractive for industrial use. The study also demonstrates that the use of such modifiers significantly reduces energy costs for metal processing. The obtained results confirm the efficiency of new modification methods for enhancing the quality of wheel steels. Thus, the application of multifunctional modifiers significantly improves the physics-mechanical characteristics of steel, making it more competitive. The scientific novelty of this study lies in proving the advantages of using multicomponent modifiers, which provide a higher degree of steel purification and alloying compared to traditional technologies, enhancing its reliability and productivity.

The usage of additive technologies in fire test stands

Volodymyr Bakun, Oleksandr Marynoshenko (Author) — Mon, 23 Dec 2024 00:00:00 +0200

The article considers the peculiarities of the use of additive technologies in the systems of test stands for liquid rocket engines, in particular, 3D printing of metal parts of assembly units. The impact of these technologies on key aspects of development is highlighted, including increasing efficiency, shortening production times, and reducing costs for the manufacture of complex parts. Due to the possibility of creating complex geometric shapes, additive technologies allow to ensure the flexibility of constructive solutions, which allows you to quickly adapt the components of test stands to changing conditions or changing the direction of research. This is especially true in environments where frequent modifications need to be made in response to test results, requiring rapid production of new or improved components. The article also considers the aspects of increasing the reliability of elements of test stand systems, which are achieved by reducing the risks of defects in the structures of materials manufactured using additive technologies. The importance of minimizing the number of internal cavities and microcracks, which can reduce the strength and tightness of components in liquid rocket engines stands that operate under high pressures and extreme temperatures, is emphasized. Examples of the implementation of elements of test stands systems manufactured using 3D printing are given. A significant reduction in the time for the production of prototypes and an increase in the efficiency of the testing process are demonstrated. Additive manufacturing also minimizes the risks of defects in materials, which increases the overall reliability and efficiency of liquid rocket engine test stands systems. The use of 3D printing allows you to avoid additional costs for the production of complex forms, which traditionally required complex technological processes or high resource costs.

The influence of solid-state welding modes on the structure of the 12Cr18Ni10-Cu system joint

Stella Mamchur, Tetiana Nosova, Serhii Lazarets, Yevhenii Halushka (Author) — Mon, 23 Dec 2024 00:00:00 +0200

This study investigates the friction welding technology for joining the 12Х18Н10Т stainless steel and copper, focusing on optimizing welding parameters and analyzing the mechanical properties of the resulting joints. The research was conducted using experimental methods to determine the optimal parameters of friction welding. Mechanical tests, including tensile strength, hardness, and microstructure analysis, were performed to evaluate the quality of the welds. The results indicate that proper selection of friction welding parameters significantly affects the quality of the joint between the 12Х18Н10Т stainless steel and copper. Optimal welding conditions were identified, leading to strong mechanical properties and reliable joint performance. Microstructural analysis revealed uniform material distribution across the weld zone. This study contributes to the understanding of friction welding processes and the effects of different welding parameters on the microstructure and mechanical properties of dissimilar metal joints. The findings provide practical recommendations for the friction welding of dissimilar materials, emphasizing the importance of parameter control to prevent defect formation and optimize joint strength. This study offers valuable insights into the friction welding process of dissimilar materials, highlighting the role of specific parameters in controlling the formation of defects and improving mechanical properties. The findings are applicable to industries requiring durable joints between stainless steel and copper. The study focused on a limited range of welding speeds and pressures. Future research should explore a broader set of parameters to further refine the welding process and address issues related to internal oxidation and joint durability.

Diagnosis and assessment of technical condition of mechatronic modules

Tetiana Kadylnykova, Sviatoslav Savkyn, Vadym Silin (Author) — Mon, 23 Dec 2024 00:00:00 +0200

An urgent problem of the stable functioning of complex technical objects is the development of a complex system of technical diagnostics and forecasting, which would allow, based on the results of the measured values of the determining parameters, to reveal their current technical state of the object and, based on the results of observations, to predict the time of its possible failure.The technical state of a mechatronic system is determined by the set of deviations from the nominal or limit values of structural parameters, therefore, when determining the technical state, diagnostic parameters should be used - indirect values associated with structural parameters that carry sufficient information about the object of diagnosis.Making a diagnosis when assessing the technical condition of a mechatronic module is carried out taking into account the use of a diagnostic matrix, which is a logical model that describes the relationship between possible malfunctions and diagnostic parameters. It is assumed that all possible states of the object form a finite set of states.In this case, the object is a "black box" not because its internal structure and parameters are completely unknown, but because access to them is prohibited and the state of the object can only be determined by examining its initial parameters.An engineering technique for building checking, localizing and diagnostic sets based on the example of triggers is proposed, on the basis of which functional modules designed for receiving, storing and issuing information, as well as which can perform information conversion operations: shift operations, r-bit operations, conversion from parallel code, are built in series and vice versa.

Identification of heat loads on space objects re-entering thee Earth's atmosphere using machine learning methods

Volodymyr Strembovskyi, Andrii Dreus (Author) — Mon, 23 Dec 2024 00:00:00 +0200

The article is devoted to the problem of predicting thermal loads on space objects during reentry.The intensive development of near-Earth space leads to a steady increase in the number of artificial non-functional space objects in Earth orbit, which requires the search for effective methods of space debris removal.Some active and combined methods of space debris removal provide for the possibility of controlling the parameters of re-entry and the impact on the thermal regime of the object.Predicting the amount of heat is important for determining the effectiveness of thermal destruction of an object.The purpose of this work is to assess the possibility of using modern artificial intelligence methods to determine the amount of heat received by a space object while moving in the atmosphere.To solve this task, three popular machine learning algorithms were applied:Support Vector Regression (SVR), Multilayer Perceptron (MLP) and Decision Tree Regression (DTR).Based on a dataset that includes information on entry time, altitude, speed, and air density, machine learning models were trained and compared.Metrics were used to evaluate the prediction accuracy: , mean absolute percentage error, and root mean square error.The results of the study showed that MLP and DTR algorithms demonstrated high forecasting accuracy.MLP and DTR models can be effectively used to predict thermal loads on space objects.In the future, the results obtained can be the basis for creating an effective tool for predicting head load on a space object.

Methodology for determining the resonant frequencies of astronauts' bodies by electromechanical analogies

Danylo Snobko, Galyna Sokol (Author) — Mon, 23 Dec 2024 00:00:00 +0200

The paper deals with the method of calculating the resonant frequency of the astronaut's body using a model of a multimass system in which the masses of individual body parts are interconnected by elastic links with damping elements. For this purpose, the method of electromechanical analogies is applied, which allows transforming the physical model of the astronaut's body into an equivalent mechanical system consisting of masses connected by elastic elements. This approach makes it possible to more accurately determine the mechanical characteristics of the astronaut's body and take them into account when designing spacecraft structures, in particular for calculating damping systems in the astronaut's seat. For the calculation, data on the mass of each part of the astronaut's body were used, which allows for a more accurate calculation of the system's own masses and stiffnesses. Separately, the study determined the stiffness values for different parts of the body, such as the vertebral joint of the head and torso, articular cartilage of the arm and leg. The mechanical characteristics were calculated using formulas for the series and parallel connection of elastic elements. Thus, to determine the total stiffness of the system, equations for each connection were used, in particular, for the series connection of stiff elements and for the parallel connection. The calculation of the resonant frequency allows us to offer effective recommendations for the development of damping mechanisms in the astronaut's chair. This will prevent the negative impact of low-frequency vibrations on the astronaut's body, in particular on the spine and joints, which is especially important during space flights. In addition, the methodology described in this paper can be used to develop similar models for other living organisms or to improve structures that may be subjected to vibration loads.

Methodological support for determining the pitch angle program of a launch vehicle during the insertion of spacecraft into circular orbits

Ruslan Keba, Anatolii Kulabukhov (Author) — Mon, 23 Dec 2024 00:00:00 +0200

Most modern satellite systems use circular orbits to maintain the stability of constellations in outer space. The insertion of spacecraft into such orbits is carried out using launch vehicles, where the choice of the optimal pitch angle is particularly important. This choice enables either an increase in the payload mass delivered to orbit or access to higher orbits with a given payload. An analysis of telemetry data on the pitch angle variation of the Falcon 9 launch vehicle (LV) revealed patterns in the changes of the horizontal and vertical velocity components of the LV, which were not considered in previous models.The purpose of this study is to develop methodological support for creating an optimal pitch angle program based on the initial data of the LV during the insertion of spacecraft into circular orbits. The study addresses the problem of designing a pitch angle program for a launch vehicle with an inertial guidance system intended for placing a spacecraft into a circular orbit. A relationship between the pitch angles in the inertial and orbital coordinate systems is established. To select a model for the variation of the horizontal and vertical velocity components, the velocity change characteristics of the Falcon 9 launch vehicle were used. These dependencies are proposed to be described by parabolic functions.As a result of the conducted research, methodological support was developed to determine the pitch angle program of the LV through vertical and horizontal velocity components using parabolic functions. An analytical relationship was obtained for determining the parameters of the proposed model based on the final motion data of the LV during spacecraft insertion into a circular orbit. The analytical dependencies of the model parameters are consistent with numerical simulation results, confirming the reliability of the obtained findings. The developed methodological support enables the formation of a pitch angle motion program for the LV that is close to optimal, based on the initial LV characteristics and the final data for spacecraft insertion into circular orbits.

Synthesis of a series compensator for the control system of an autonomous mobile robot

Nataliia Ashhepkova , Mykola Koshovyi (Author) — Mon, 23 Dec 2024 00:00:00 +0200

A method of synthesis of compensators for control systems with forward and reverse cross-connection is proposed. The control object is an autonomous mobile robot of variable configuration. The control system of the considered class of mobile robots is multidimensional and provides, in general, three control buses for the platform, chassis and attachments. On each bus, command influences are transmitted via communication channels to executive devices (wheels, stabilizers, actuators of manipulator kinematic pairs, etc.). The interconnection of control channels arises due to the dynamic features of the object and is determined by the design variant of the mobile robot. To overcome the interaction, a series compensator must be added to each control channel. If the nomenclature of the chassis and attached equipment is known, then at the design stage, the transfer functions of the serial compensators for each channel of the control system can be calculated in advance. For example, an autonomous mobile robot with a manipulator is considered. The design consists of a four-wheeled four-wheel platform and an anthropomorphic manipulator consisting of a ring rotating around a vertical axis and rod links ( an arm) connected by rotary kinematic pairs of the fifth class. A control system for an autonomous mobile robot with a manipulator in each mode of operation contains at least four control channels with cross-connections due to the physical properties of the control object. The method of determining the transfer functions of compensators to ensure the autonomy of control channels is considered. This method can be used to analyze the controllability of the manipulator at the design stage; allows you to determine the influence of structural, kinematic and dynamic parameters on the controllability of the manipulator. Research results can be used in the development of algorithms for group control of mobile robots.

Stability analysis of the control system of an autonomous mobile robot

Nataliia Ashhepkova (Author) — Mon, 23 Dec 2024 00:00:00 +0200

The results of a stability study for control systems with forward and reverse cross-talk are presented. The object of control is an autonomous mobile robot with an aggregate-modular design. The control system of the considered class of mobile robots is multidimensional and provides, in general, three control buses for the platform, chassis and attachments. The interconnection of control channels arises due to the dynamic features of the object and is determined by the design variant of the mobile robot. To overcome the interaction, a series compensator and correction circuit are added to each control channel. If the nomenclature of the chassis and attached equipment is known, then at the design stage, the transfer functions of the corrective circuits for each channel of the control system can be calculated in advance. For example, an autonomous mobile robot with a manipulator is considered. The design consists of a four-wheel drive platform and an anthropomorphic manipulator consisting of a ring rotating around a vertical axis and rod links (arms) connected by fifth-class rotary kinematic pairs. The control system for an autonomous mobile robot with a manipulator in each mode of operation contains at least four control channels with cross-connections due to the physical properties of the control object. With the help of the introduction of the corrective circuit, it was possible to achieve absolute autonomy of the control system. According to the logarithmic frequency characteristics for each of the cross-connections, the stability reserves of the autonomous control channels are determined. The stability of autonomous regulation channels determines the stability of the considered BSAR. The research results can be used in the development of algorithms for group control of AMR.

Segments with functions of observation of orbital objects and communication as part of an integrated satellite system

Tetiana Labutkina, Oleksandr Akinshev (Author) — Mon, 23 Dec 2024 00:00:00 +0200

The topic of the article is at the junction of three scientific and practical areas, which are important components in the development of space activities: maintaining up-to-date information about a set of objects in near-Earth orbits; application of network information technologies in space; creation of satellite systems based on the principle of multifunctionality, implementation of integration of functions within one satellite system, combination of satellite systems for different purposes into a single functionally integrated system. The article proposes an approach to the construction of different-height segments with communication functions and observation of orbital objects that are part of a functionally integrated satellite system on different-height orbital groups. In this case, the communication function is presented as a basic-auxiliary one for the implementation of the target function of observation of orbital objects (as a “platform” function of the system), and as a target function of the system (which is one of the target functions of the system). The article is divided into two parts. The first part of the article proposes two conceptual solutions for constructing orbital segments of an integrated satellite system, in which the function of observing orbital objects is implemented. According to the first concept, the observation segment of orbital objects contains only observer spacecraft that implement communication and observation functions. According to the second concept, the observation segment also includes communication spacecraft that relieve observer spacecraft from establishing lateral connections in one segment and from implementing intersegment connections. The second part of the article is devoted to the development of approaches to comparing the characteristics of the system's functioning under different conceptual design solutions. In the system structure, elementary structural units of the same type (communication groups) are distinguished, which ensure the communication of the functional units of the system, represented by observer spacecraft or functional pairs of observer spacecraft. The system's functioning indicators calculated for the communication group are acceptable for the characteristics of all groups of this type in the system and characterize the system as a whole. The results of numerical calculations are obtained, which represent the results of a comparative analysis of the application of the two proposed conceptual solutions.This publication presents the first part of the article.

Analysis of the development trend of the space industry and the reliability of the provision of launch services

Oleksandr Polosmak, Olena Grebenkina, Anatolii Kulabukhov (Author) — Mon, 23 Dec 2024 00:00:00 +0200

An important task after the creation of a satellite is its launch by means of a launch vehicle (LV). The organization of spacecraft (SC) launch is a very complicated process, which includes solving several important issues such as obtaining a license for frequency bands, selecting a launch service provider, and meeting the requirements for the SC on the LV. Also important are the issues related to the mission of the CS and how this mission coincides with the trends in the space industry. The cost of these services and their reliability are also important. The purpose of this paper is to conduct an analytical review of the trends in the development of the space industry and launch service providers and to assess the reliability of these services. The main tasks of the research: analytical review of the development trend of launch services and directions of development of spacecraft missions; definition of the tasks of the launch organization; assessment of the reliability of launch services.The mission with which the space vehicles are launched is of great importance. It is the mission that determines the choice of orbits, the term of active existence, methods of disposal after the end of the term of active existence. The conducted analysis shows that the most promising and widespread are communication satellites and DZZ, which have a double meaning.Based on statistical data, the reliability of launch services is assessed. It is determined that the launch services provided by the main suppliers have high reliability (about 99%), and among the suppliers at the moment, taking into account the availability (number of launches) and reliability (100% in 2023), is the Falcon 9 LV. The analysis of the cost of launch services made it possible to estimate the preliminary costs of launching a SC depending on its mass and the launch service provider. Recommendations for the creation of new promising SC that can be used at the design stage have been obtained.

DETERMINATION OF THE STRESS-STRAIN STATE OF THE STRUCTURAL ELEMENTS OF THE SPACE HEAD MODULE AND CPMPARISON OF THE CALCULATION RESULTS WITH THE EXPERIMENTAL DATA

D. Akimov, D. Klymenko (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Annotation. Calculations of structural elements of the space head module were carried out taking into account the real deformation diagrams of the material, the stress-strain state was determined and the results of calculations were compared with the obtained experimental data. A comparative analysis of the calculated values of stresses and stresses obtained during test showed that for all considered cases, the calculated stresses exceed the test ones by 12-15%. A comparative analysis of the calculated displacement values obtained during the tests in the upper belt of the space head module slightly exceed those obtained during the calculations. This is explained by the fact that the values of structural clearances are added the amount of displacement during tests. Where there are no structural clearances, in particular in the lowed belts, the calculated displacement values practically coincide with those obtained during testing. The results of the analysis and experiment showed a high correlation, which allows predicting with a high degree of probability the ultimate, from the point of view of strength, load of structural elements of the space head module in conditions close to operational ones. Analysis of the stress-strain state of structures that are being tested allows, after testing and identifying defects in the structure, to draw a reasonable conclusion regarding the possibility of further use of the construction.

DEVELOPMENT OF A PNEUMATIC SYSTEM FOR SEPARATING STAGES OF A SPACE LAUNCH VEHICLE

D.A. Udovichenko (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Annotation. Examine pneumatic system of separation stage, which ensure minimum angle speed and exclude pollution surface of space vehicle. On examplesystem of separation «Cyclone-4» launch vehicleexaminemethod determination kinematic parameters, command timeline, pneumatic system feed of compressed gas from tank to pneumatic pushers, executive body relative speed and them fastening to module. The pneumatic system of separation stage consist of the source gas, the executive body, pipes, which tangent the source gas and the executive bodyand valves for sealing the source gas. Basic the executive body creating relative speed pneumatic system of separation stage is pneumatic pusher. The pneumatic pusher is power pneumatic cylinder, which plunger move out of body, when admission into the body control pressure and create necessary force and do necessary work for create necessarykinematic parameters of system separation stage. The method definition kinematic parameters include differentialequation, which describe motion two rigid bodyin the plane and differentialequation, which describe process flow gas from tank to pneumatic pushers with definitiontermodynamic parameter of conditiongas. Similar method wasapplied for definition kinematic parameter of system separation leaf fairing and got experiment confirmation validity application method of calculating. For solution system non-linear ordinary differential equation was applied special numerical method integration. The result modeling system separation stage and stage block of spacecraft show, that provide need relative speed separation and unstressed process with record maximal possible dispersion pressure in pneumatic pusher, forces strength in connector and the guide studding.The result research givedvaluable data for construction system separation stage and blocks of spacecraftlaunch vehicle and showed possible apply pneumatic system for separation stages. The material article were helpful scientific and engineers technician worker, which work above create construction of system separation stages and keep dynamic transition process system separation stages launch vehicle space setting.

NUMERICAL RESEARCH OF THE INFLUENCE OF CONTROL RUDDERS ON THE AERODYNAMIC CHARACTERISTICS OF THE K110 SU SUBORBITAL ROCKET

I. Lukianenko, S. Alekseyenko, O. Kulyk (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract. Aerodynamic research plays an important role in the development and design of aircraft. In particular, such studies can evaluate the characteristics of suborbital rockets in terms of maximum range, altitude and speed, determine the stability and controllability properties, and assess the mechanical loads acting on structural elements. An important aspect of aerodynamic analysis is the determination of aerodynamic forces and torques. This paper investigates and analyzes the aerodynamic characteristics of the K110 SU ultralight class suborbital rocket, taking into account the effect of control rudder deflection. The study was carried out by means of numerical modeling methods based on the Navier-Stokes equations using the SST k-ω turbulence model. The features of the flow around the surface of the rocket body in subsonic, transonic, and supersonic modes at the deviation of the control surfaces in the range of ±10° are analyzed. The data on the main aerodynamic characteristics of the rocket depending on the flight speed and the angle of deflection of the control surfaces were obtained. The structure of the flow, namely the vortex structures formed behind the control surfaces of the aerodynamic rudders and their interaction with the rocket stabilizers, is investigated. The obtained results allow for a deeper understanding of how rudder deflection affects the behavior of the rocket in the atmosphere at the stages of flight from subsonic to supersonic speeds and will be used to further develop the control system of the K110 SU ultralight rocket and optimize its aerodynamic characteristics. The results will be used in the development and design of the control system of the rocket.

FORMATION OF THE EFFECTIVE FOCUS DISTANCE OF PYROTECHNIC DEVICES OF SEPARATION (SEPARATION) SYSTEMS OF LAUNCH ROCKET. LITERATURE REVIEW

Y. Boliubash (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract. In rocket and space technology (RST), reducing the mass of the launch vehicle (LV) design is considered a key factor for ensuring competitiveness. One of the promising directions in achieving this goal is the use of separation systems (SS) using pyrotechnic devices (PD) based on linear shaped charges (LSC). They are light, cheap and effective. LSC are installed at a certain distance from the dividing structural element. The distance that provides the greatest efficiency of PD is called the focal distance. The article examines the influence of the focal length of setting the cumulative PD on the process of separation of the element of the LV design. It was established that the focal length is an important design parameter that affects: the efficiency and reliability of the separation system of the LV; the weight of the structure of SS and LV, etc. The factors affecting the focal length were analyzed, such as: the shape of the cumulative part (CP) of the LSC; cumulative jet length (JL); cumulation mode; the level of technology for the production of LSC; type of obstacle material, etc. Axisymmetric cylindrical cumulative charges (CCC) and planar symmetric LSC are considered. The results of research by various researchers are given in the form of dependences of the depth of CP penetration into an obstacle for the CCC and LSC. The complexity of the analysis and generalization of scientific information on this topic is described. Examples of analytical work based on the study of existing information, a table with the main parameters of the LSC, the dependence of the penetration efficiency of the LSC on the size of the focal length are given. The ranges of focal lengths for the installation of LSC in RST are considered. According to the results of the literature review, a set task of determining the actual focal length of the LSC installation in the hull compartment of the LV is proposed, which allows taking into account the influence of a number of factors, including deformations of the LV body compartment and technological tolerances, which will increase the efficiency and reliability of the separation of the elements of the LV structure. The results of the research can be used in the design and development of SS on the LSC for LV, optimization of the parameters of LV separation systems, improvement of efficiency and reliability of separation of LV structural elements, reduction of LV mass and cost. The materials of the article can be useful for scientists and engineers working in the field of RCT; specialists engaged in the design and development of separation systems for liquid waste; teachers and students of higher educational institutions.

OPTIMIZATION OF COOLING CIRCUIT PARAMETERS COMBUSTION CHAMBERS OF LIQUID ROCKET ENGINE

О. Litvinov, H. Koloskova, O. Kondratenko (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract. The standard design of the liquid engine chamber does not take into account the mass characteristics of the chamber, although the mass perfection of the engine installation is one of the main requirements in the design of rocket. The aim of the work was to optimize the parameters of the cooling path of the combustion chamber of a liquid rocket engine under the conditions of the minimum mass of the structure. To solve the optimization problem, an objective function was created that reflects the dependence of the camera mass on its geometric characteristics and consists of three components, namely: the mass of the outer shell, the inner corrugation, and the outer shell. The objective function depends on 6 parameters and is a multi-parameter problem, the solution of which is impossible in such a setting. An analysis was carried out and it was determined that the outer shell has the greatest influence on the mass characteristics of the camera, and not so much its thickness as its diameter. Therefore, the number of variables was reduced to three, and the tract height, corrugation pitch, and corrugation angle were adopted as the variables that most affect the diameter of the outer casing. Technological limitations on geometric characteristics and limitations on gas wall temperature within 5% are taken as limitations. For the calculation, the chamber was divided by length into sections, and the optimization problem was solved by the method of the generalized given gradient within each separate section. Since the problem is solved with respect to 3 parameters, one parameter was fixed during the calculation (the angle of inclination of the corrugations) and the other two were found under the condition of minimum mass. For each site, parameters were invented for which it has a minimum mass. It should be noted that with this approach to design, the weight savings can be up to 15%. It was found that the mentioned approach has certain disadvantages, and according to the length of the chamber in each section we have our own height of the cooling path, which causes certain difficulties and may even make it impossible to assemble the chamber as a whole. Therefore, to solve this problem, it was proposed to fix the height of the corrugations in these sections, and to choose only the angle of inclination and the pitch of the corrugations as variables when solving the optimization problem. With this approach, mass savings can be up to 10%.

RESEARCH OF THE MAGNETIC FIELD OF AN ELECTRIC ARC JET ENGINE ON METAL PLASMA

E.V. Spirin, V.M. Nadtoka (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Annotation. Electric jet engines on metal plasma have significant advantages over gas ion engines. Metal plasma engines do not require gas storage containers, valves, or piping. The technical parameters of vacuum-arc motors on metal plasma are at a high level, which necessitates the development of more powerful motors that use a stationary or quasi-stationary arc discharge. The purpose of the research is to develop a magnetic system for controlling the trajectory of the movement of cathode spots of the arc discharge over a large area of the cathode to ensure the possibility of operation at high power of the arc discharge. The study of the magnetic field of an electric arc jet engine on a metal plasma (ERDMP) with different permanent magnets and with different options for the operation of control solenoids was carried out. By changing the amount of current through the solenoid, you can move the trajectory of the cathode spots along the surface of the cathode, uniformly evaporating its surface. The use of a permanent magnet instead of a central solenoid made it possible to reduce the weight and dimensions of the magnetic system, as well as to reduce the cost of electricity for moving the arc of the magnetic field lines. Different configurations of the shape of the magnetic field arch and their influence on the trajectory of cathode spots of the arc discharge and erosion of the cathode were investigated. The result of the conducted research is the improvement of the design, functioning algorithms, and the optimization of the operation of the ERDMP, which will allow creating an engine with increased technical characteristics.

DEVELOPMENT OF A DIFFERENTIAL MODEL FOR COOLING AN LPRE CHAMBER BY AN INCOMPRESSIBLE FLUID

V. Sliusariev, V. Bucharskyi (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract. The combustion chamber constitutes a crucial component of a liquid rocket engine (LPRE), and approximately 30% of serial engine failures are attributed to issues within it. Primarily, challenges encountered during engine chamber operation stem from the inadequacy of the current cooling systems to manage thermal loads effectively. These loads, unique to liquid-propellant rocket engine chambers, result of high pressures, temperatures, and flow rates of dissociating combustion products. Regenerative cooling stands as the primary method to safe the chamber walls from overheating and subsequent deterioration. Other methods serve as supplementary measures, often utilized in conjunction with regenerative cooling (e.g., internal film cooling), or are tailored to specific applications, such as radiation cooling of upper-stage engine nozzles. However, the advancement of heat transfer theory within liquid-propellant rocket engine chambers has been relatively stagnant, with widely accepted calculation methods established as far back as the 1970s. Consequently, these methods fail to harness the considerable computing power enhancements since their inception, neglect new experimental data, and lack adaptation to modern engine manufacturing technologies like 3D printing. Concurrently, the burgeoning number of startups in the rocket and space sector, constrained by limited budgets, necessitates the swift development of viable designs without extensive and costly testing. Hence, the need for validated calculation methods for regenerative cooling is paramount. This study endeavors to address this need by formulating a system of differential equations, grounded on the mass, momentum, and energy conservation laws, to describe the processes within the cooling circuit of the liquid-propellant rocket engine chamber. Additionally, the model is dimensionally reduced for simplification. Comparative analysis against established engineering methodologies showcases the advantages of the proposed approach, underscoring its potential for enhancing cooling system design efficacy.

GRAPHENE FOR ROCKET ENGINE COOLING, THERMAL PROTECTION OF THE MAIN FAIRING

V.P. Zeleny, T.V. Nosova, S.I. Mamchur (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract.The temperature in the combustion chambers of rocket engines reaches 3000K, so cooling systems play an essential role. The temperature of the main fairing reaches 800К, it is necessary to ensure the protection of the aluminum case with the minimum weight of the protection. In this work it is proposed possible ways of using graphene for cooling rocket engines, thermal protection of the main fairing.The purpose of the work is to substantiate in the first approximation the use of graphene for the production of the nozzle of a liquid rocket engine, the use of graphene plates for the production of combustion chambers of liquid rocket engines, the production of thermal protection of the main fairing of the rocket - the carrier involves the use of graphene. The justifications in the first approximation for the use of graphene in rocket and space technology, in particular for thermal protection of the rocket engine and the main fairing, are given. Such a complex of properties allows the use of graphene in RD cooling systems. Graphene membranes that can withstand a pressure of 50-80 atm can be used for heat removal in the combustion chamber.Graphite is considered promising for thermal protection in rocket and space technology. Graphene can be used to cool the nozzle: the nozzle consists of two walls, between the walls gas circulates at cryogenic temperatures (liquid). The inner wall is usually made of copper, but the density of copper is 4 times greater than the density of graphene, the thermal conductivity of copper is an order of magnitude lower than the thermal conductivity of graphene. It is proposed to make the inner wall from graphene, the melting temperature of which is much higher than the temperature of the gases passing through the nozzle, so there is no need for cooling with fuel components.Such measures will simplify the design of the nozzle, make it more reliable, and reduce weight. Taking into account the high cost of graphene, it is proposed to carry out theoretical studies of calculations regarding the use of graphene in elements of rocket and space technology.

ANALYSIS OF TECHNOLOGIES FOR OBTAINING AND PROCESSING DEEP HOLES IN THICK-WALLED PARTS

I.I. Karpovych, D.V. Savinkin (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract. Improving the quality of the inner surface of deep holes in thick-walled parts in the manufacture of new products such as pneumatic and hydraulic cylinders is a very urgent task. A similar technology is used in the defense industry to produce barrels and launch containers. The purpose of this work is to investigate the technologies for manufacturing and processing deep holes in thick-walled parts to improve their quality and efficiency in production processes. The work is based on a comprehensive approach that includes the analysis of existing methods and technologies for deep drilling, experimental research on factors affecting surface quality, and the development of recommendations for process improvement. The main factors affecting the surface quality of deep holes were identified, and recommendations for improving the processing were developed. It is determined that the most effective methods of control over the processing process are a combination of direct contact method of control of geometry and surface roughness. The study expands scientific knowledge about deep drilling processes and the processing of thick-walled parts, proposing new approaches to improving processing quality. The obtained results can be used in production processes to enhance the quality and efficiency of deep hole processing in thick-walled parts. The research offers a comprehensive approach to solving the problem of deep hole processing, including the creation of a universal device with integrated real-time quality control. The study is limited to the analysis of existing methods and technologies in modern engineering. Future research could focus on further optimization of the developed recommendations and their implementation in production.

METHOD OF ADJUSTING THE SENSITIVITY OF ULTRASONIC CONTROL OF WELDED JOINTS WITHOUT USING STANDARD SAMPLES

P.G. Kyselov, S.V. Klymenko (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract. Recent years have been characterized by intensive development of additive technologies and scientific analysis of physical and chemical phenomena during welding of 3D printed products from various materials. It is necessary to solve the problem of optimizing not only the welding itself, but also the quality control processes that follow it. The performance of welded products and structures largely depends on the quality of connections, and therefore their safety during operation for the surrounding environment and people. Requirements for the quality of connections include the following main indicators: reliability and strength; macro- and micro-geometry of the connection and seam; faulty connection; metal structure and its heat treatment. To control the quality of welding, destructive and non-destructive tests are used, and the latter, as a rule, prevail. Internal defects are mainly detected by ultrasonic and radiation methods. Magnetic methods are used to control subsurface and surface defects in ferromagnetic materials. Surface defects in the form of thin cracks are found using capillary methods - color and fluorescent defectoscopy. Smaller through-hole defects can be detected by vacuum and helium leak detection techniques, hydro and pneumatic tests. The quality of products mainly depends on the level of technology of its production. Therefore, an important factor of modernity is the transition to active management of welding quality through the use of feedback from control to technology. In other words, an urgent task is on the agenda: the development of non-destructive ultrasonic quality control of welded joints of products manufactured by additive technologies with the ability to adjust sensitivity using DGS diagrams, which will provide a standard-free adjustment of the flaw detector.In this way, it is possible to achieve material benefit due to the absence of a certain number of standard samples, since it will be possible to adjust the sensitivity of the defectoscope by the calculation method, knowing the physical properties of the material of the controlled object. Also, to a certain extent, the described method of ultrasonic control with sensitivity adjustment according to AAD-diagrams can act as an alternative to X-ray control of welded joints, due to the simplicity of control implementation, safety and financial component.

MODERN EQUIPMENT AND ELEMENTS OF TECHNOLOGY FOR ELECTRON BEAM WELDING ON THE SURFACE OF THE MOON

S.O. Hlushak, N.V. Piskun, Y.H. ʼTernovyi (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract. The work presents an analysis of the physical conditions of outer space and the surface of the Moon, their influence on the operation of welding equipment and the execution of the technological process of welding. The purpose of this work is defined and research tasks are set. The relevance of the work and the need to use welding in the development of the Moon, where long-term lunar bases will be created, as well as other objects that ensure life and the work of expeditions, have been proven. These can be assembly and assembly operations during the creation of space complexes or repair and preventive works related to ensuring the duration of operation of existing systems An analysis of the existing welding methods was carried out and it was proved that electron beam welding is a suitable technological process for welding in space conditions. It is shown that with this process, the effective efficiency is 85-90%, which is the maximum compared to other welding methods. Electron beam welding in the conditions of earth's gravity allows to ensure the mechanical and chemical properties of welded joints, as well as their density almost at the level of the main metal of the structure, which is impossible with other methods of welding. Thus, the coefficient of strength of the weld metal of welded joints made of aluminum alloys obtained by electron beam welding is 0.85...0.93, and with arc and plasma-arc methods it is 0.7...0.8. At the same time, obtaining such properties of welded joints in space conditions is complicated. Of course, the reduced gravity, low temperatures, and ultrahigh vacuum that are the natural environment on the lunar surface contribute to the formation of internal voids in the form of pores in welds. This, first of all, manifests itself when welding aluminum alloys, which are used as the main material in the constructions of space vehicles. To eliminate these shortcomings, a modern technological process with pre- and post-welding heating is proposed. At the same time, the welding process is performed with mixing of the molten metal by a circular reverse periodic deflection of the electron beam, which allows you to get rid of the formation of pores in the welded joints. To carry out this process, a new modern electron beam gun was developed and a system of apparatus for periodic deflection of an electron beam with a programmable intensity of heating along a given trajectory was manufactured.

EXTREME STUDY OF CONNECTING FLANGE CONNECTIONS OF CARBON PLASTIC ROCKET ROCKET CRYOGENIC PIPELINES

O. Litot, T. Manko (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Annotation. The article is devoted to the issue of manufacturing and experimental research of all-composite linerless cryogenic pipelines of carbon-plastic carrier rockets, the parts of which are made by the winding method. When they are created from composites, the task of designing, forming the material and manufacturing technology is solved at the same time.Taking into account such a feature of composites, the improvement of manufacturing technology is one of the most important aspects that determine the accounting of the entire structure. Of particular interest is the study of the removable flange connection in the structure of the cryogenic pipeline made of carbon fiber. The technological features of their production are presented. Considerable interest in these issues is caused by the study of the connection of cryogenic pipelines and elements that supply fuel components for tanks made of composite materials. For this purpose, a flange is used, the design of which significantly affects the tightness of the structure.This is justified by the high difference in the coefficients of linear temperature expansion of the material of the elements in contact, the sealing material, the quality of the surface and the tightening moments of the fastening elements. The design of flanges and individual elements of the technological mandrel is considered. The main structural and technological solutions for the production of the composite casing of the pipeline are given. Hermeticity was assessed and theoretical studies of the stress-strain state of the flange were confirmed. The study of the detachable flange connection as part of the structure of the cryogenic pipeline made of carbon fiber was carried out.In order to assess the tightness and confirm the theoretical studies of the stress-strain state of the flange, autonomous hydraulic tests were carried out with the internal excess pressure of liquid nitrogen. The obtained experimental structures were subjected to repeated cooling in order to simulate filling/inflating/draining cycles, simulating work as part of a cryogenic pipeline, followed by checking the assembly for tightness with helium.

INFLUENCE OF MODIFICATION OF CAST AND DEFORMED ALLOYS ON MECHANICAL PROPERTIES OF COMPOSITIONS

T. Man’ko (Translator) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract. The work is devoted to the important and urgenttask of creating structures in mechanical engineering from various aluminum-basedalloy sandde for mable alloys with in creased and actively controlling mechanical properties. The regularities of the complex effect of modification with a powder modifier based on boron carbide B₄C on the structure and mechanical properties of the alloy АМг6 of the Al−Mg system and AL2 Al−Si−Mg in the as-cast and heat-treated states have been determined. Complex parameters were improved by modification of aluminum melts and heat treatment of alloys in the solid state. The work uses modern the oretical and experimental methods of materials research, including the study of microstructure, X-ray structural analysis and mechanical tests. The structure and phase composition of alloys of the Al–Mg and Al–Si–Mg systems were in vestigatedat different cooling rates. The structure of unmodified AMg6 and AL2 alloys, which crystallized at different cooling rates, consists of weakly branched α-Al dendrites rounded in cross section of the solid solution and various intermetallic compounds. Determining the regularity of structure formation and properties of АМг6 and АЛ2 alloys in the modified stateis distinguished by the selection of multiphase dispersed intermetallic compounds of the type Al₅SiFe, Al₈SiFe₂, TiС, TiВ₂. An improved mode of heat treatment of alloys was developed, carried out according to the regime: heating temperature is 535 ⁰С, exposure for 3.5 hours, cooling – in water with sequential aging at 175 ⁰С, exposure for 3 hours. The established regularities made it possible to obtain the composition of modifications and thermo-time parameters of heat treatment. Obtained alloys with a significantly increased set of mechanical properties. As a result, a complex processing "modification of 0.05% B₄C + heattreat ment" of the AMg6 alloy is recommended, which provides an increase in the strength limit to anaverage of 10%, and plasticity - 2 times compared to the original un modified state.

OPTICAL DATA PROCESSING SYSTEM

A. Dymchneko, A. Panfilov, S. Klymenko (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract. The article analyzes the technical solution for the implementation of the optical data processing module for the product of the "Rocketry Agency" Student Rocket project and identifies the main research perspectives for its use and development. The prospects for the development of scientific and research development of systems of this type are the creation of new schemes of technical solutions and mathematical and practical methods of processing stream data for finding optimal algorithms for their processing and analysis in real time, as well as reducing the cost of production of guidance systems for small aircraft (SA) of high and average productivity of the linear acceleration system. Taking into account the caliber of the D-150 and D-300 missile launchers and the features of its linear acceleration system, special attention was paid to the processes of minimizing the mechanical dimensions of the system, increasing the failure resistance and simplifying the production processes of the mechanical components of the system, as well as minimizing the time of accumulation and processing of streaming arrays of monochrome binary data for ensuring the necessary speed of operation of the electromechanical bodies of the control system. The main principle of the system implementation was the combination of a controlled electro-mechanical gyroscope based on a brushless high-speed motor and a high-speed optical scanner of the infrared range in combination with a digital sensor for measuring small distances. The system also uses an autonomous calibration module based on a complex of inertial micro-electromechanical systems (MEMS) as sensors of the initial spatial orientation system. The main tools for determining the angular position of the system were the mathematical spatial-geometrical functions of processing the received data. The main mathematical apparatus for data processing will be an 8-bit controller in combination with a high-speed camera-scanner and an external optical sensor for distance measurement. To ensure the necessary positioning accuracy of the system, a suitable optical module is used, which provides a given focal pattern for the electronic optical surface scanner. An important addition to such a spatial orientation system is a mechanical two-stage gyroscope, which is also designed to be placed in the declared calibers of the aircraft for further standardization of the fastening system and the design of the corresponding mass-dimensional layout.

INFORMATION TECHNOLOGY FOR TESTING STATISTICAL REGULARITIES OF COMPUTER SOFTWARE GENERATOR

V.P. Malaichuk, O.D. Klymenko (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract.In the paper, an overview of software generators of pseudorandom variables is carried out, the scope of application of pseudorandom variables is given. The total number of criteria for checking the statistical regularities of computer program generators was determined, and five criteria, which are most often used for checking in computational experiments, were studied. The conducted research confirmed the need to check the statistical regularities of computer generators, because this is especially important when applying them in computational experiments and applying the obtained results in various fields of knowledge (cyber security, simulation modeling, technical information protection systems, modeling of military operations, measuring equipment and computer computer games). Among such criteria are defined in the article: the Sherman, Chang-Spiring, Moran, Fronzini, and Greenwood-Quesenberry-Miller criteria. In the course of the research, it was determined that the following generally accepted requirements must be observed when designing and implementing generators of pseudorandom sequences: simplicity of hardware or software implementation; maximum speed; maximum approximation of the sequence obtained at the output of the generator to the theoretical law of distribution (not necessarily uniform); the ability to control output parameters; the possibility of operation of generators of pseudorandom sequences in a wide range of frequencies; the ability to quickly reconfigure its work depending on the choice of initial parameters. Thus, the development of information technology will allow to automate the process of checking statistical regularities of computer software generators and will provide an opportunity to ensure the adequacy and correctness of the results of statistical analysis.

USAGE OF BI-LEVEL ATTENTION ROUTING MECHANISM TO IMPROVE SMALL YOLO MODELS

R. Syzonenko, S. Klymenko (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract. In recent years, UAVs have been able to cover most of the tasks previously performed by manned aircraft. As UAV technology continues to evolve, the number of drones in countries around the world is growing every year, and according to data showing global commercial drones by year and sales statistics, by 2025 there will be approximately 2679000 UAVs in the world, with a market size of approximately USD 12.6 billion. So, this indicates the rapid development of UAVs and their proliferation. However, the rapid growth in the field of UAVs increases the number of challenges associated with the recognition of moving objects. Factors that may affect the appearance of additional conditions may include changes in angle, variability of lighting, various variations in the size and shape of objects, overlapping objects, noise, etc. According to a study conducted in 2020, more than 70% of errors in object recognition in UAV images are due to insufficient accuracy of the algorithms. Given the above problems and challenges, the development of effective methods for detecting and recognizing objects for UAVs is an urgent and important task that requires further research and development. Therefore, this paper addresses the issue of improving small YOLO models with the help of a Bi-level routing attention mechanism. The study was conducted on the VisDrone2019 dataset. The evaluation results show certain advantages the usage of the Bi-level routing attention mechanism brings to the YOLOv9 algorithm, especially an increase of up to 1.3% in mean detection accuracy, compared to the baseline model. Along with the increase in accuracy, the intervention speed, model size, and number of floating-point operations per second (FLOPs) are considered. Study shows that an increase in accuracy decreases the speed of the model, therefore this tradeoff should be taken into account, to find balance for each separate use case.

COMPARATIVE STUDY OF THE MATHEMATICAL MODEL OF THE PROPELLANT TANK PRESSURIZATION SYSTEM

V. Alieksieienko, V. Bucharskyi (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract. The pressurization system of launch vehicle (LV) fuel tanks serves to maintain a specified excess pressure in the tank's gas cushion, based on calculated requirements for fuel component supply and tank design. This necessitates the coordination of all elements within the pressurization system. This paper examines a pressurization system consisting of single high-pressure cylinder, the fuel tank and the connecting line with the metering element. To maintain the required excess pressure in the gas cushion, pressurization gas is supplied with the mass flow rate dependent on the parameters within the high-pressure cylinder. This excess pressure ensures a consistent flow rate of fuel components to the pumps or combustion chamber. System elements such as the gas reducer and gas pipes are treated as a single line with an equivalent flow rate coefficient. The objective of this work was to develop a mathematical model of the system described above. The suggested model includes a system of ordinary differential equations for both the high-pressure tank and the fuel tank, which is derived from the conservation laws of mass and energy, as well as the equation of state for the pressurization gas. The model takes into account the gas reducer by allowing for changes in the area of the gas outflow section over time. The model's operation was simulated, revealing that with a constant cross-sectional area of the gas line, the deviation in the mass flow rate of the fuel component during tank emptying is up to 4% of the nominal value. Implementing a linear law of area change reduced this deviation to 1%. Overall, the results confirm the accuracy of the proposed method for calculating tank parameters, making it suitable for designing rocket pressurization systems.

ANALYZING THE POSSIBILITY OF USING A CUT SHAFT IN THE CONNECTION OF THE STEERING DRIVE WITH THE ADR

V. Baburov, V. Gusev, D. Klymenko (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Annotation. In the course of product development, tasks arise related to the need to modify the existing standard design in order to solve unplanned design problems that arise during operation. Let’s consider the solution of this problem on the example of design modification to eliminate gaps in the spline connection. In order to ensure the elimination of gaps in the splined connection of the steering drive with the ADR, which arise during manufacturing due to tolerances, it is proposed to perform a longitudinal cut along the entire length of the splines and installation of a spacer bushing with preloading. Calculations and strength tests of the finalized design of the steering drive shaft connection to the aerodynamic rudder were carried out. Comparison of the obtained experimental and calculated data is carried out. The finite element method and the MSC.NASTRAN software package based on it were used in the calculations. Analytical methods were also used for preliminary assessment. The results of the preliminary strength evaluation by analytical method showed that the strength of the split shaft is not ensured. Refining calculations of the stress-strain state of the split shaft with account geometrical and physical nonlinearity (type of analysis Nonlinear Static) have been carried out. The analysis of the results showed: satisfactory convergence of calculation of stress-strain states for the most distant point of section “petal” (high stresses in the zone of “slot” are caused by stress concentration); the strength of the shaft by normal stresses is not provided; the strength of the shaft by the von Mises criterion is provided. A decision was made to conduct static tests of the split shaft and a test program was developed. According to the test results, the strength of the split shaft is sufficient for all loading cases. According to the results of calculations and strength tests, the design of the split shaft with the installed spacer bushing can be accepted for use in the product. Analysis of the results of calculated and experimental data showed satisfactory convergence of the results when the IV theory of strength is used for analyzing the calculations.

MODEL FOR ESTIMATING PRESSURES OF CONTACT INTERACTION OF RAILS WITH THE WHEEL OF RAILWAY TRACKS OF COSMODROMES

O. Yushkevych, D. Berezhnoi (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract. The operation of cosmodromes depends on the smooth functioning of internal railway transport. The reliability, durability and operational stability of rail parts depends on the well-established and systematic operation of the launch complex. At the same time, the maximum values of contact pressures between the rail and the wheel should not exceed the tensile strength or yield strength of the material. Otherwise, the rail collapses or loses its shape due to wear and plastic deformation, which is unacceptable when it works. The study of contact pressures is necessary to solve the problem of the strength of railway rails in the places of their contact with the wheels of rolling stock. The middle part of the tire, with which the wheel is mainly in contact with the rail, is made slightly tapered. The diameter of the wheel is usually understood as the diameter of a circle located at a certain distance from the inner ridge face of the bandage. In the study of contact pressures, it is quite possible to neglect this small taper and consider the contact of the wheel and rail as the contact of two cylinders with mutually perpendicular axes. Prior to deformation, these cylinders touch at a point. After the deformation of the wheel and rail, the point contact passes into touch on the elliptical platform. Physical, mathematical and computer models of contact interaction between a railway wheel and a rail have been developed. The computer code created in the C programming language for modeling the parameters of contact interaction, calculates the values of the highest pressure and the dimensions of the contact area at different loads, taking into account the properties of the materials of rails and wheels and their geometric parameters. The developed computer model solves the problem and the results of its work correspond to the well-known analytical calculation. The constructed models can be used to obtain input data for further calculation of the stress distribution along the axis of the rail head section.

CLOUD COMPUTING ORGANIZATION IN NEUROPHYSIOLOGICAL RESEARCHBASED ON EYETRACKING DATA

A. Ilutsa, V. Gidulian, V. Pavlenko (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract. A working version of the software complex/platform (IONDS - Identification of nonlinear dynamical systems) has been developed in the web environment, which is an interface and functionality for cloud computingin neurophysiological research based on eyetracking data. The complex allows you to carry out automated research on the identification of nonlinear dynamic systems and add new methods using the built-in code editor. Also, it is possible to edit and interpret the script code of any identification method, add a list of experiment parameters to the code, perform calculations using the integrated script code on the server, receive results already in the browser, and save them. The software complex consists of many independent modules and nodes working in interaction. This allows you to quickly and efficiently scale its functions and capabilities. An important feature of this software complex is that it does not require hardware on the client side thanks to cloud computing. Also, the software complex has advantages in relation to known similar platforms, namely: social opportunities and a high level of abstraction when working with the complex. As a result of the work, a software complex based on the method of identification of the eye-motor system was developed and tested, which is advisable to use in scientific activities to simplify work with identification methods, namely: saving the script code of identification methods for further work with them; improvement of identification methods using the built-in code editor; exchange of identification methods; the possibility of working with the platform on any device due to the fact that all calculations will be performed on the server ("cloud computing"). Also, the software complex can be used in the educational process due to the above advantages and the library of software identification tools.

ANALYSIS OF ASSESSMENT ERRORS OF DYNAMIC CHARACTERISTICS OF THE OCULOMOTOR SYSTEM OF HUMANS ACCORDING TO THE EYE-TRACKING DATA

V. Pavlenko, D. Lukashuk (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract. For mathematical modeling of the human oculomotor system (OMS), integral nonlinear models are used, which simultaneously take into account the nonlinear and inertial properties of the research object. Based on the data of experimental studies of the OMS "input-output", transient and diagonal intersections of transient functions of the second and third orders are determined. To obtain experimental data, an innovative eye tracking technology is used, which allows recording eye responses to test visual stimuli. Thus test signals are displayed on the computer monitor at different distances from the starting position in the horizontal direction. The aim of the research is to study the accuracy of OMS identification using eye-tracking data by evaluating the calculation errors of multidimensional transient functions when using methods of nonlinear dynamic identification based on models in the form of Volterra series and polynomials. The object of the study is the process of nonparametric identification of the OMS based on Volterra models in the time domain. The subject of the research is algorithmic and software tools for calculating the dynamic characteristics of OMS based on eye-tracking data, analyzing the accuracy of the obtained models using two identification methods: the approximation method and the least squares method (LSM). The means of nonlinear dynamic identification of the human OMS based on Volterra series and polynomials were developed in the Python programming environment. The accuracy estimates of various OMS (linear, quadratic, and cubic) models were obtained based on data from three responses to test signals of different amplitudes. For the same test signals, the same models in the form of the Volterra series and polynomials were obtained, as these models coincide in the region of convergence of the Volterra series. The analysis of errors in the assessment of the dynamic characteristics of the OMS demonstrated that the model in the form of an integral polynomial of the second degree, which was built using the LSM based on three responses, has an accuracy twice as high as the accuracy of similar models built using the data of two responses. Thus, in further studies of the psychophysiological state of a person based on nonlinear dynamic models of the OMS according to the data of three responses, it is advisable to use a model in the form of a quadratic Volterra polynomial.

DETERMINATION «METHOD OF SIZE» GEOMETRICAL PARAMETERS OF GLASSCERAMIC CONSTRUCTIONS FOR RECEIPT OF THEM MAXIMAL STRENGTH PROPERTIES

V. Satokin (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Annotation. Conducted in SDO Yuzhnoye analysis calculations strength hinged glassceramic plastins brought author to scientific discovery "method of size", which yet on the stage of design in ANSYS, allows to determine the geometrical parameters of glassceramic plastins, which will realize them maximal strength. Calculations of the strength of glass-ceramic plates under the influence of a temperature difference were carried out. Preliminary strength analysis was carried out by engineering methods. The main strength calculation was carried out using the ANSYS complex. Two options for securing the glass-ceramic plates were considered: on the end - pinched fastening, and on the lower perimeter - hinged fastening. A comparative analysis of the safety margin shows that in the case of pinched fastening of glass-ceramic plates, the increase in thickness leads to a decrease in the safety margin both for the reference temperature of 600°С and for the reference temperature of 50°С. This behavior coincides with the results of the engineering calculation. A completely different picture is observed when the plates are hinged. At first, the reserve increases, and then begins to decrease, or vice versa: first decreases, and then increases - depending on the reference temperature. All physical properties for all models of glass-ceramic plates are set the same. The only variable is the "size" of the plates. The analysis of the results of strength calculations for hinged fastening of glass-ceramic plates led the author to a scientific discovery, which was called the "size method" - the study shows that there are optimal geometric parameters of glass-ceramic plates (in this case, thickness and diameter) to realize their maximum strength properties. The application of the "size method" for modeling the stress-strain state of glass-ceramic plates operating under the influence of temperature loads will allow to determine at the modeling stage the values of the geometric dimensions of structures that will ensure their maximum strength and to determine unacceptable plate sizes for specified operating modes.

SPACE TUG WITH A HYDROGEN-OXYGEN POWER PROPULSION PLANT

M. Baranov, S. Gubin (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Annotation. The article considers a spacecraft containing hybrid power and propulsion systems based on a solar battery and an electrochemical battery, a reversible fuel cell with a water tank as a working fluid, which together provide power to all onboard systems and power two types of engines - a gas rocket propulsion system and an electric rocket propulsion system.The solar panel generates energy to power the main systems connected to the central bus. The systems include: electrochemical energy storage, specialized onboard consumers, a reversible fuel generator, gas automation, and an electric rocket engine. The reversible fuel cell operates in two modes: as a water electrolyzer and as an electrochemical generator. In the water electrolyzer mode, water is dissociated into hydrogen and oxygen, which are then accumulated in the corresponding flexible storage tanks. From the tanks, these components will be fed to the gas propellant rocket engine through gas automation. The engine should perform a pulsed Hohmann orbital transfer, creating a high-speed space tug mode. Subsequently, the excess water supply, which is converted into hydrogen and oxygen, is converted into electrical energy in the electrochemical generator mode and performs cogeneration with the solar panel of the necessary energy to power the predominantly electric heating corrector engine, which also uses the produced hydrogen as a working fluid. Thus, the reversible fuel generator is used as an electrolyzer at the stage of extraction of fuel components and as a powerful additional energy source in the electrochemical generator mode. This solution makes it possible to use safe propellant refueling operations at the launch using water as the propellant and to transfer the extraction of explosive hydrogen and oxygen components directly to the mission. Mass characterization calculations also determine a more favorable launch mass of water as a propellant.

RESULTS OF EXPERIMENTAL DATA ON NOISE LEVEL MEASUREMENTS IN THE ACOUSTIC FIELD OF THE QUADROCOPTER

D.V. Mykhaliov, G.I. Sokol (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract. Currently, quadrocopters, which belong to unmanned aerial vehicles (UAVs), are actively used in the civil and military spheres, especially since they are typical emitters of low-frequency sound. Low-frequency sound when propagating has a low attenuation coefficient in air. Also, by registering this sound from the quadrocopter, you can determine its bearing and destroy the device. Therefore, there is a need for experimental research and calculation of the characteristics of the general acoustic field from the 4 propellers of the quadrocopter. A review of works on the noises of quadrocopter propellers and modern quadrocopter-type UAVs and their designs was carried out, which made it possible to choose a quadrocopter for research. They became the Syma X23 quadrocopter, which has a small size (210x210x50) mm and no camera on board. The characteristics of the quadrocopter and its equipment that emits low-frequency sound are considered, the reasons for the appearance of this sound, which are formed during the flight of the quadrocopter, are analyzed. The main sources of UAV noise are engines and propellers. Electric motors installed on quadrocopters are the quietest available for them. Therefore, we believe that the source of the noise is the screws. To calculate the characteristics of the general acoustic field from the 4 propellers of the quadrocopter, we use the theory of L. Ya. Gutin, which describes the sound field of the propeller. The principle of superposition, which is used for small pressure amplitudes, is the basis of sound simulation from 4 screws. The calculations were performed in the MathCad 15 software package. This made it possible to construct a characteristic of the directionality of the acoustic field from one propeller and to calculate the acoustic pressure from 4 propellers at a distance. It was determined how the sound pressure changes with the distance from the quadcopter. Experimental studies and measurements of noise levels of the general acoustic field from 4 propellers of the quadcopter were carried out, which amounted to 89.1 dB.

THE CONCEPT OF THE GREENHOUSE MODULE OF MOON BASE

A. Pustovharov, H. Osinovyj (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Annotation. The world’s leading space powers are paying more and more attention to the exploration of the Moon. In the near future, it is planned to start colonizing the Earth’s natural satellite rather than just exploring it. Short manned expeditions to the Moon are expected in the coming years. Gradually it is expected to move to ensuring the permanent presence of people on the surface to the Moon. Lunar bases will be established for this purpose. To reduce cargo traffic from Earth to the Moon, to increase the safety of lunar bases, to reduce their dependence on supplies from the Earth and to form ecological systems of a closed type (with the circulation of substances), it is advisable to have greenhouses in the structure of lunar bases. The purpose of this work was to develop the concept of a greenhouse module. The initial data and constraints that affect the design and characteristics of the module were taken into account, the concept of its use was formed, in particular — the functions and equipment required for work on the Moon were determined. The use of different plant crops was analyzed, and optimal crops were selected taking into account the needs of lunar bases. First of all, attention is paid to carbon dioxide absorption and oxygen production, for which the use of chlorella algae in special reactors is envisaged. The supply of plant food is provided by means of conveyor greenhouse devices in which higher plants are grown. The design of the module is developed, its systems are described. The energy consumption is roughly calculated. The most rational arrangement of equipment and systems inside the module is chosen. The conceptual design resulted in some characterizations and generated a view of the greenhouse module. The means of delivery of the module to the Moon, including a super-heavy launch vehicle, were described. The application of the latest design methods, including 3D modelling, allowed the conceptual design of the module to be carried out at a high level. The conducted work allows us to conclude that the lunar industrial research base greenhouse module is an important and promising means of studying and development the Moon.

TOPOLOGIES OF THE INTEGRATED SATELLITE COMMUNICATION NETWORKBASED ON GLOBAL SATELLITE SYSTEMS AND SMALL CLUSTERS OF SPACECRAFT

T. Labutkina, M. Perepelytsia (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract. The concept of an integrated satellite system was developed, which combines two components: 1) a global grouping built on the basis of groups (segments) of different heights, for each of which the structure is maintained regularly; 2) a set of clusters of spacecraft is applied on a system basis, each of which is represented by a small orbital grouping and is used to solve the task of orbital service or the task related to the fight against space debris. According to the concept of an integrated satellite system, a set of functions (presented in different compositions in each segment) is integrated based on different height segments of its global grouping. To the set of functions of the global groupings of the system, the functions of organizing the application of the named set of clusters on a system basis are introduced. At the heart of the integrated satellite system is a single integrated communication network that combines the network of the global grouping and the network of clusters. The concept of the space vehicle cluster communication network and the general concept of cluster construction is developed. The groupings of the cluster include operational spacecraft and communication spacecraft, which have a stably supported angular orientation relative to the axes of the barycentric orbital coordinate system and implement communications based on optical communication lines or beams of a phased antenna array. These communication lines are software controlled (or have basic software control). Communication spacecraft provide the cluster's external communications and create the basic structure ("foundations") of the cluster's internal network. In addition, spacecraft-communicators are interconnected centers of "star" topological structures, which are created by the lines of joining operational spacecraft to them. The connection of spacecraft-communicators with operational spacecraft is carried out based on network technologies like those implemented in local networks and networks of megalopolises LoRa or LoRaWAN. In this way, a single cluster network is created. Examples of some specific variants of cluster groups and cluster networks are given. The concept of the topology of the unified global network of the integrated satellite system is presented. The nodes of the basic part of this network (basic network) are the spacecraft of the global grouping in a single design or the root spacecraft of the distributed satellites of this grouping, as well as the spacecraft-communicators of the cluster. The topology of the basic network for each current moment of operation is defined and constantly maintained (in the imaginary situation of no information to be transmitted by the communication line, the communication device still provides software orientation of the line, and service signals are transmitted through the line at specified time intervals). The complete network topology in addition to the basic network topology contains nodes that are represented by operational spacecraft attached to liaison spacecraft, as well as companion spacecraft attached to root spacecraft in distributed spacecraft in the global grouping (attachment technologies are like those applied in LoRa, LoRaWAN networks). The paper proposes a method of presenting information about the topology of an integrated satellite network in the tasks of its simulation modeling, as well as current tasks of its functioning. The method makes it possible to use an information-enhanced connectivity matrix, which contains not only data on the presence of a connection between a pair of network nodes, but also the possibility to "quickly" (with little time) obtain information about a pair of nodes implementing this connection, and about the types of communication devices used by nodes of this pair.

SPACE X MARKETING STRATEGIES TAKING INTO ACCOUNT CURRENT MARKET TRENDS

B. Ocheretyanyi, O. Dzhur (Author) — Thu, 13 Jun 2024 00:00:00 +0300

Abstract. The role of marketing strategy at enterprises was studied, its importance for market orientation was determined, and measures and directions for development were directed. The interrelationship of various strategies of the enterprise through the hierarchy of strategic intentions of the enterprise, which shape its success and efficiency in the long term, is shown.The process of creating a marketing strategy is described, including the analysis of the relationship between the consumer and the product, the general marketing strategies for various market segments are defined, the development of strategies for individual components of the marketing mix is described, as well as the process of ensuring implementation and control. Analyzed trends that involve market focus and product orientation in marketing strategies and that ensure overcoming the strategic gap by using old products in new markets and introducing new products in established markets. On the example of SpaceX, innovative marketing strategies were studied, which are the basis of its success in the competitive aerospace sector. Shown as a hierarchy of strategic intent, SpaceX's mission to revolutionize space exploration and its emphasis on reusable rocket technology in particular is an example of how a sound marketing strategy can drive long-term growth and market penetration. Successful measures of SpaceX's marketing strategy are highlighted, such as social media strategies and traditional marketing methods, which ensure transparency and efficiency of interaction with its audience. The author's definition of marketing strategy is formulated, its main features are highlighted. The successful components of the modern marketing strategy of the aerospace company SpaceX are proven and highlighted, as an example for application in the aerospace services market by other market participants.

PROBLEMS OF CONTROLLING THE COMBUSTION PROCESS IN SFRE BY MEANS OF SOUND VIBRATIONS

V.S. Kozin (Author) — Mon, 10 Jun 2024 00:00:00 +0300

This article relates to rocket and space technology, namely to solid rocket engines. The problem of controlling the operation of a solid rocket engine is still relevant today. The article deals with the issue of controlling the combustion process in the charge channel of a solid rocket engine using ultrasound. The active influence of ultrasound on physical processes, which affects their course, is mainly due to nonlinear effects in the sound field, and transverse waves are used for this purpose. The influence of longitudinal and transverse ultrasonic vibrations in the combustion chamber of a SFRE is considered. Longitudinal compression waves, which increase the pressure and increase the combustion rate, increase the acoustic instability, and transverse waves, which activate the evaporation of ammonium perchlorate from the surface of solid rocket fuel, also increase the combustion rate, but at half the speed of longitudinal waves. A scheme for introducing an ultrasonic waveguide-emitter into the charge channel of a solid propellant is proposed. A numerical assessment of the intensity of ultrasonic wave transmission through the gas medium of combustion products of the SFRE, the wave resistance of this medium through which the sound wave passes, the coefficients of sound pressure transmission and energy transmission was carried out. The obtained numerical values of these quantities are in satisfactory agreement with the results of other literature sources. The results obtained can be used in further studies of the processes of damping pressure fluctuations at high-frequency instability of the SFRE operation and determining the limits of possible application of the combustion law at high frequencies of pressure pulsations in the combustion chamber. The results of the paper can be used in the design of new solid-fuelled rocket propulsion systems.

DEVELOPMENT OF THE DEVICE FOR CONTROLLING AND MEASURING THE SUPPLY OF WORKING GAS FOR LABORATORY TESTING OF THE ELECTRIC PROPULSION THRUSTERS

Viktor Pererva, Olexandr Petrenko, Oleksandr Aleksieienko (Author) — Mon, 10 Jun 2024 00:00:00 +0300

The object of the research is a device for measuring, controlling, and indicating the flow rate of working gas during laboratory testing of electric propulsion systems for space applications. The problem lies in the need to ensure high accuracy in controlling and measuring the flow rates of working gas for such devices. The obtained results include: analysis of existing industrial flow meters that could be used in development; proposed structural and functional diagrams of the device; experimental investigations into the accuracy of the developed device. Based on the analysis of parameters of the most common flow meters for development, the Bronkhorst F-201CV-100-AAD-22-V regulator was selected. Based on the selected regulator, a device was developed with a 32-bit ARM architecture. This architecture provides for the use of floating-point calculations, easy reprogramming of the device, and fast indication of values displayed on the indicator. The device features galvanic isolation between the control bus and the UART port of the microcontroller. The device allows for regulation, measurement, and indication of the flow rate of working gas into the anode block and hollow cathode during testing of Hall thrusters. Using the device allows for recommendations regarding the design of onboard systems for supplying working fluid to electric rocket propulsion systems. Based on the presented development and conducted research, laboratory prototypes of the devices were manufactured. The measurement error throughout the entire range of working gas flow rates does not exceed 0.7%. The overall error of the stand control and measurement system for working gas flow rates is up to 3%. The developed device provides measurement accuracy that satisfies the developers of electric propulsion systems.

HEAT TRANSFER CRISIS DURING EVAPORATION OF LIQUID METAL FROM THE SURFACE OF A CAPILLARY-POROUS STRUCTURE

Stanislav Bilogurov (Author) — Mon, 10 Jun 2024 00:00:00 +0300

The object of study of this research is the thermophysical processes that occur during heat transfer from a cooling surface with a capillary-porous structure (CPS) during phase transitions of the coolant. Increasing the increased thermal stress capabilities of components and assemblies of power plants, both ground- and space-based, requires reliable and safe cooling of these elements. The aim of this work is to determine the main parameters of the coolant system for the application of a more efficient method of cooling the heat-stressed elements of liquid rocket engines.To accomplish this task, it is most appropriate to use substances with high critical parameters, such as liquid and alkaline metals, as heat transfer fluids.The emergence of new materials and technologies for their production requires additional research in the field of heat transfer in capillary structures and on their surfaces, which gives a significant effect compared to flat surfaces. Using the principle of operation of heat pipes with capillary-porous structures to provide reliable cooling of liquid rocket engines of low thrust, for satellite correction and orientation, makes it possible to significantly reduce the mass and size characteristics of the installation compared to traditional cooling methods. In this regard, in this work, the experimental determination of the heat transfer coefficient on capillary-porous surfaces during the evaporation of alkali metals was chosen as a research method to determine the main effective parameters of the CPS. Quantitative dependences of the heat transfer coefficient on the evaporation coefficient were determined. The limit of the influence of capillary pressure on the evaporation coefficient is given and the main causes of the heat transfer crisis during the evaporation of liquid metals from capillary structures are identified.

INFLUENCE OF WELDING PARAMETERS ON THE PERFORMANCE CHARACTERISTICS OF THE THERMOCATODES

A.F. Sanin, I.A. Mamchur , S.I. Mamchur, T.V. Nosova (Author) — Mon, 10 Jun 2024 00:00:00 +0300

Methods of controlling welding parameters, physical and physico-chemical transformations that occur during welding are considered in the work. The physico-chemical mechanism of welding is considered - the deformation of the crystal lattice, the transfer of metal on the contacting surfaces, the mixing of deformation products, diffusion, phase transformations, the appearance of new chemical compounds - intermetallics, oxides, carbides. Studies of the influence of the main parameters of friction welding on the formation of the structure of the welded joints of the investigated alloys have been carried out. The microstructures of welded joints OT4 + VN-2AE and VT6 + VN-2AE are given. The obtained dependence of the relative strength of the OT 4 + VN-2AE connection on the parameters of the welding process. The given microstructures were obtained by SEM from the surface of OT 4 + VN-2AE and VT6 samples, based on which it was determined that the destruction begins with the formation of microcracks in the contact zone on the side of the VN-2AE niobium alloy. It was determined that a layer saturated with oxygen is formed in the diffusion zone due to which the β-modification of Ni2O5 with a significant specific volume is formed, which causes high internal stresses and the formation of microcracks. The reason for the decrease in the mechanical properties of the welded joint OT 4 + ВН-2АЕ was established - the formation of a phase (Ti-Nb) with an orthorhombic lattice, the degree of curvature of which determines the degree of strengthening of the layer and depends on the niobium content. These data are confirmed by X-ray structural analysis. The analysis of the concentration curves of niobium and titanium shows that titanium does not diffuse into the narrow contact zone of the niobium alloy, and niobium forms a wide diffusion zone in the contact zone of the OT 4 alloy. It was established that niobium contributes to the increase in the solubility of aluminum in λ-titanium, which leads to increase in weldability plasticity and corrosion resistance. It was determined that the low mechanical properties of the welded joints of the VN-2AE alloy with the OT-4 and VT-6 titanium alloys are due to the same nature - the oxidation of the niobium alloy at the welding temperature. It was established that the weak link of the welded joint is the surface of the niobium alloy.

ENHANCEMENT OF MECHANICAL PROPERTIES OF STRUCTURAL STEEL 09G2S

T.V. Nosova, S.I. Mamchur, Y.V. Moroz, Y.V. Tkachov (Author) — Mon, 10 Jun 2024 00:00:00 +0300

The influence of modification on the process of crystallization, structure and mechanical strength of structural steels has been established. The subject of the article is relevant and suggests the possibility of moving mechanical authorities beyond the flow of modification into structural development. Structural steels 09G2 and 09G2S are considered, which are used for all types of welded structures, including naphtha and gas pipes [2]. Both offer static and dynamic ideas. Ferite-pearlite steels are not subject to thermal processing. Improvements in the properties of heat-resistant steels can be achieved through a change in grain size, a sharper grain boundary, and the formation of a submicrocrystalline structure through plastic deformation or modification. At the same time, it is possible to remove such structural components, if these officials can make a total contribution to the

transfer of value, for example, in the process of vicarious modification of alloys with dispersed compositions. The

final and modified castings of steels 09G2 and 09G2S promoted intense plastic deformation with subsequent low-temperature melting at a temperature of 350 °C. The output of distillery steels 09G2 and 09G2S has a small ferite-pearlitic structure with an average size of the primary austenite grain of 30 µm, after modification and deformation the grain size of the alloy is 10 µm. After hardening and cooling near water, the structure changed to ferite-troostite, with an average grain size of ~ 8 ... 10 μm. After cooling the cured samples from the mixture (20% NaCl in water), the structure of packet martensite was obtained. The output structural steels have insufficiently high mechanical strength (microhardness and fluidity). During the hour of soaking near water, the hardness increases. The most recent indicators indicate samples of samples from NaCl, for the preparation of detailed martensitic crystals (under an hour of accelerated cooling. A technological process of intense plastic deformation of forks of steels 09G2 and 09G2S. The output structure and strength of the steels after processing have been repaired. The results are to be seen in the manner of the passes. a change in the grain size of steels has been achieved 3 times and the fluidity range has been moved. Priming has been carried out using a selected type and fraction of modifier. Titanium-based powders have been primed, obtained by plasma-chemical synthesis. Titanium carbide powders have been removed. It has a chemical warehouse assigned to it, and the technology for introducing a modifier into a steel melt has been developed. Clearly modified castings with a uniform structure have been removed. Intense plastic deformation and heat treatment of steels have been carried out. Steel with a small grain size has been modified, 3 times finer than the output, and the micro-drill has been advanced. the flow and between the fluidity are equal to the output. Thus, to refine the grain and increase the value of the power of the steels, Available methods: modification, intense plastic deformation combined with thermal processing.

RESEARCH OF HEAT RESISTANCE OF CARBON-CARBON COMPOSITE MATERIALS WITH PROTECTIVE COATINGS OBTAINED USING FUNCTIONALLY ACTIVE CHARGES

Dmytro Sereda (Author) — Mon, 10 Jun 2024 00:00:00 +0300

This study focuses on the development of protective coatings for carbon-carbon composite materials (CCСM) used in high-temperature processes in aerospace engineering. CСCM have limitations due to their susceptibility to oxidation, erosion, and burnout in gas streams. Our research is aimed at creating protective coatings using functionally active charges (FAC) obtained under non-stationary temperature conditions and improving the performance of composites. The aim of our study is to identify the optimal compositions of powders for chromium-alloyed protective coatings using functionally active charges to increase the heat resistance of the working surface. We analyzed various methods of obtaining protective coatings, including chemical-thermal and liquid-phase saturation methods, to find out their peculiarities in interaction with the CCСM matrix and changes in their mechanical properties. In addition to the traditional methods, we have investigated the method of saturating the surface with a solid phase in an active gas environment using FAС, which are obtained under non-stationary temperature conditions. This method provides high quality coatings, reduces processing time and makes it possible to work at high temperatures depending on the composition of the spray coatings. Much attention was paid to the problem associated with chemical interaction and formation of carbide phases, which are important for ensuring the stability of coatings under high temperature conditions. Experimental studies include a factorial experiment to determine the compositions of powder mixtures that provide high heat resistance. Various independent variables, such as the content of chromium, silicon, titanium, and aluminum, were considered, taking into account their influence on the physical and mechanical properties of coatings. Particular attention was paid to the optimization of the parameters of thermal autoinitiation of the functionally active charge under process conditions. Regression equations are presented to evaluate the dependence of the wear resistance of coatings on the autoinitiation parameters and the content of alloying elements. The analysis of the study results includes the construction of three-dimensional graphical dependencies for optimizing the composition of powdered CBA in the Cr-Al-Ti and Cr-Al-Si systems. In practice, chromium-aluminum-siliconized coatings obtained under isothermal conditions, when tested for heat resistance, have a more porous surface through which oxygen penetrates to the surface of the HCCM. Compared to the coatings obtained using FAS, the heat resistance is 1.5-1.7 times higher, which can be explained by the higher concentration of chromium, aluminum, silicon, and titanium, which contribute to the formation of protective oxide membraness. The low-porosity surface of the coatings obtained using functionally active layers prevents oxygen from entering the material, contributing to the formation of oxide protective membranes such as SiO₂, TiO₂, Cr₂O₃, Al₂O₃.

FORMATION OF CHROMATED COATINGS ON A PRESS TOOLING IN THE PRODUCTION OF RUBBER PRODUCTS FOR ROCKET AND SPACE TECHNOLOGY

B. Sereda, A. Udod (Author) — Mon, 10 Jun 2024 00:00:00 +0300

This research analyzes the influence of residual stresses formed as a result of the process of self-propagating high-temperature synthesis on the mechanical properties and durability of structural materials and protective coatings. The main emphasis is placed on the analysis of the relationship between residual stresses and adhesive strength and durability of the obtained coatings. Rubber-based composites may prove to be competitive and eventually replace traditional materials in a number of applications, as there are many advantages to using these materials. For example, rubber-based composites often have a lower density than traditional materials such as metals. This leads to a reduction in the weight of products, which is important in a variety of industries where lightness is a key characteristic. Rubber composites are characterized by cushioning, flexibility, and elasticity, which makes them able to handle dynamic loads and adapt to various forms of deformation without losing structural properties. Research was carried out on parts of press tooling used for manufacturing of rubber-technical products in rocket-space engineering. It was found that residual stresses formed during the SHS process have a significant effect on the adhesion properties of protective coatings. Residual stresses appear after SHS treatment under conditions of thermal self-ignition of SHS charges. At the cooling stage of the SHS process, residual compressive stresses appear as a result of the elastic interaction of the alloyed titanium coating and the structural material, which have different sizes and coefficients of thermal expansion. The maximum values of adhesion strength of titanium coatings on steel 45 were 120-150 MPa when alloyed with aluminum and 180-210 MPa when alloyed with chromium. This research emphasizes the importance of residual stress control for improving the strength and durability of protective coatings obtained under SHS conditions and their possible role in extending the service life of structures and equipment. Additional research in this direction may contribute to process optimization and product quality improvement in the aerospace industry.

METHODS OF QUALITY CONTROL FOR AEROSPACE PARTS, PRODUCED WITH 3D-PRINTING OUT OF COMPOSITE-REINFORCED POLYMERS

M. Sirenko, O. Karpovych (Author) — Mon, 10 Jun 2024 00:00:00 +0300

One of the features of parts, made from polymer composite materials, is that the part and material are both formed at once, when the part is being made. Complexity of interaction processes between matrix and reinforcing fiber makes it difficult to achieve prognosed characteristics of part due to possible imperfections of manufacturing processes and technology. Therefore, an important part of parts life cycle is quality control. Quality control can be destructive or non-destructive, the latter giving more information and insight on defects of the part itself and, possibly, at flaws in manufacturing technology. With the increase in popularity of use of additive manufacturing technologies, especially – FDM 3d-printing, in aerospace industry, there’s a need to improve the performance of parts. Benefits of FDM 3d-printing is the absence of need for specialized forming equipment and tools, especially for forming the parts with complex, topologically-optimized geometry and structure. One of the ways to improve printed parts performance and its physical properties is to use continuous fiber reinforcement. Because of need to control the state and position of the fiber in the part, quality control is also an important part of this type of additive manufacturing. Existing popular methods of quality control, used in polymer composite materials part manufacturing were reviewed. Also, the features and limitations, imposed by structure of printed parts and printing technology were reviewed as well, the differences of them and polymer composite parts made in traditional forming ways, were noted too. The destructive testing methods reviewed are tensile stress testing, bend testing and impact stress testing. The non-destructive quality control methods reviewed are visual, acoustic, radiological and ultrasound. Also, recommendations on their use on FDM 3d-printed parts were formed. As a result, visual and ultrasound methods were accepted as non-destructive methods of quality control, with need to perform destructive tests on sample parts as well. Also, as a promising method, thermography was proposed, yet because of the limitation of using it with high-temperature polymers, its utility is also limited.

VACUUM SYSTEM FOR COATING PARTS OF ROCKET AND SPACE EQUIPMENT

Dmytro Bondar, Volodymyr Nadtoka, Maksym Kraiev (Author) — Mon, 10 Jun 2024 00:00:00 +0300

A vertical type vacuum plant was created for applying coatings using the ion-plasma deposition method to the inner surface of hollow products with a diameter of up to 200 mm and a length of up to 1000 mm. The plant includes: a vacuum chamber with a vacuum system, an evaporator with a magnetic system, a power supply and control system, a cooling system. Radial evaporation cathode of tubular shape with controlled arc is used. Inside the cathode is a magnetic system that controls the movement of cathode spots on its surface. Permanent magnets create arched magnetic fields that hold the position of the discharge track in the tangential direction. The trajectory of the movement of the cathode spots has the form of an ellipse stretched along the cathode. For uniform spraying of the cathode surface, the track moves in two directions: around the circumference of the cathode surface and along its length. A mechanism for moving the magnetic system is mounted on the cover of the vacuum chamber. The product to be coated is mounted inside the vacuum chamber in a vertical position thanks to the removable top cover. The necessary rarefaction of the atmosphere (vacuum) is achieved with the help of two vacuum pumps. Coating materials are traditional Сr and Ni-Cr alloys. A feature of the coating structure is presented: the formation of a combination of solid condensed and soft droplet phases. The droplet phase is a part of the evaporator material with several times lower hardness compared to the nitrided condensed phase. The distribution of the soft phase in a strong coating prevents its brittleness, which is important for thick coatings. The disadvantage of the vacuum-arc deposition process is the heating of the part to a temperature of 380-450 °C. To exclude the softening of the main metal of the combustion chamber and nozzle, it is recommended to use bronze alloys with a recrystallization temperature of at least 500 °C.

A STUDY OF PROPERTIES OF AUSTENITIC STEEL IN THE INITIAL STATE

S.A. Bozhko, A.F. Sanin, V.V. Bielikov, V.V. Khutornyi (Author) — Mon, 10 Jun 2024 00:00:00 +0300

High-manganese steel is used in the rocket, space, and defense industries due to its low specific gravity, stable austenitic structure over a wide temperature range, and ability to strengthen under mechanical deformation. However, the wider application of this steel is hindered by such factors as: instability of mechanical properties in the initial state, tendency to thermal embrittlement and very poor machinability. Therefore, the work is aimed at solving the problems of eliminating the above-mentioned negative factors. Conducted studies of the effect of temperature-time parameters on the structure and properties of steel made it possible to establish the mechanism of thermal embrittlement of 9Г28Ю9МВБ steel. During slow cooling from hot deformation temperatures with speeds of the order of 0.03 º/s in steel, a large number of gray-blue coarse phase particles are released, which are located on the grain boundaries, which causes a sharp decrease in impact viscosity. It was established that in the temperature range of 500-800 ºС, the solid solution disintegrates with the release of particles of the strengthening K-phase - (Fe, Mn)₃AL, C_x. It was determined that the simultaneous decrease in hardness and impact strength in the temperature range of 750-950ºС provides a significant improvement in machinability. The lowest values of mechanical properties are achieved during aging at 700 ºС, the improvement of machinability in this case is maximal compared to exposure to other temperatures. So, for example, with an increase in the temperature of isothermal holding at 650ºС for 35 hours. machinability improves by almost 1.7 times, and for the same time at 700 ºС – by 2.4 times. When the holding temperature is increased to 950ºС for 35 hours. the machinability of steel increases only 1.6 times, which is due to the less intense decomposition of the saturated solid solution. Significant anisotropy of mechanical properties is formed as a result of the development of liquid chemical heterogeneity and its imitation during further thermomechanical processing. The value of the coefficient of anisotropy in sample bars of different grades of initial steel reaches values from 1.5 for a bar with a cross section of 105x105 mm to 3.9 units for a bar with a diameter of 120 mm. The study of the influence of the annealing temperature on the homogeneity of austenitic steel made it possible to develop a mode of heat treatment of austenitic steel 9Г28Ю9МВБ, which consists of heating to 1250°С, holding for 2 hours. at this temperature and subsequent cooling in water, in order to fix a homogeneous supersaturated solid solution. After such heat treatment, the striated microchemical heterogeneity is significantly reduced, the anisotropy coefficient does not exceed 1.1 units for all types of steel assortment.

AUTOMATED CONTROL SYSTEMS FOR THE MANUFACTURE OF AXISYMMETRICAL COMPOSITE MATERIAL PRODUCTS

Y.S. Myhovych, S.V. Klymenko (Author) — Mon, 10 Jun 2024 00:00:00 +0300

The paper examines the peculiarities of manufacturing products from composite materials using the winding method, providing a description of existing winding methods. Two main winding methods are presented: filament winding and spot winding. The characteristics of using winding methods employed in production are outlined. It is determined that filament winding is used to create cylindrical and conical shells from composite materials by winding fibers onto a form using a moving head. The particularities of this method include the ability to wind onto various shapes, adjustable roller speed, and the need for specialized machinery. Spot winding is used to manufacture shells from composite materials using material strips. It allows for creating layers from strips wrapping around the surface of the form, shaping composite products. The main features of this method include the possibility of using double winding to increase strength and process efficiency in manufacturing products from composite materials. Precise fiber and resin delivery play a crucial role in the production of axisymmetric products from composite materials, achieved through automated fiber delivery systems and resin dosing systems. An analysis of modern automated control systems used to optimize the winding process is conducted. It is determined that automated control systems include numerical programming, which enhances process control levels, and high-precision sensor equipment for monitoring and quality control of products, enabling detailed analysis of various product parameters such as size, shape, texture, etc. The main aspects of manufacturing axisymmetric products from composite materials using the winding method are proposed, taking into account temperature balance and pressure. Additionally, the application of automated control systems in the production process of axisymmetric products from composite materials will optimize resin or other binder dosing, thereby improving product quality and durability.

DEVELOPMENT OF A CLASSIFIER FOR SPACE OBJECTDEORBITING SYSTEMS

A. Abaturov (Author) — Mon, 10 Jun 2024 00:00:00 +0300

This paper presents the results of the creation of a faceted classification system and the development of a classifier for space object deorbiting systems from Earth orbits. The main objective of the work was to develop a systematized and standardized classification system for space object deorbitingsystems. In the course of the work, the main classification features of the deorbitingsystems were identified. It was found that different systems can have the same classification features, which greatly complicates the determination of the hierarchical relationship. As a result, the faceted classification method was chosen. The classification features were divided into two groups: the general group covers the main properties of the deorbitingsystem without specifying specific technical implementation options, while the functional group includes technical details of the system implementation. Facets were defined for each classification feature. Based on the faceted classification system, a classifier was developed that uses a parallel coding system, where each facet is coded separately from the others. The decimal system was chosen to encode the features. The coding structure has the format "XXXXX-XXXX", where the first five characters correspond to the general group, and the following four to the functional group. Based on the results of the work, a classification system and a classifier of space object deorbitingsystems were developed. The advantage of the developed classification system is its flexibility and ease of use. Thanks to the use of the facet method, the system can be easily supplemented with the necessary facets and expanded. This faceted classification system makes it possible to standardize the development and modeling of space object deorbiting systems.

COMPUTER SIMULATION OF THERMAL REGIME OF THE PAYLOAD DURING INTERPLANETARY FLIGHT IN THE OUTER COMPARTMENT

Mon, 10 Jun 2024 00:00:00 +0300

One of the emerging trends in space technology development is the increasing focus on interplanetary travel and the exploration of the Moon and Mars. Particularly with in the frame work of the international Artemis program, object ivesareset for Moon exploration, necessitating the delivery of correspondin grese arche quipment to the lunarsur face. Developers of rocket and space technology face the challenge of preserving the functionality of valuablecar goduring interplanetary transportation. Ensuringac ceptable ther malregimes in the extreme conditions of out erspaceiscrucial. This taskis complex, given the limited arsenal of temperature control method savailable. Primarily, the seme tho dsrely on the use of efficient ther malinsulation materials to preven the atlossin the cold vacuum of space oroverheatingduetosolarradiation. In corporating additional active ther malregulation systems requiresextra energy, which is constraineda board space craft. The Artem is project entailsthede velopment of new ther malcontrol technologies to main tainstable ther mal conditions for valuablecargo during missions to the Moon, including the utilization of effective electronic-vacuuminsulation, heatregulati on systems, and otherinnovativesolutions. This paperad dresses the challenge of determining the optimal parameters for the thermal control system in the compartment of the landingmodule transporting the Cube Rover. A simpl if iedma the matical model describing the heatexchange process based on solving ther adiation heatex change problemis presented. Computational model ing of the rmalconditions for valuablecargo, corresponding to the transport ation conditions with in the Peregrinemission of Astrobotic company, is conductedusing the Thermal Desktops of twaresuite. Through computational experiments, optimalins ulationparameters for the rover-compartmentaredetermined with in specified energy and size-mass limitations.

MATHEMATICAL MODELING OF DIRECT ENERGY DEPOSITION PROCESSES

O.V. Karpovich Karpovich, E.O. Karakash, D.S. Zhumar, O.M. Taran (Author) — Mon, 10 Jun 2024 00:00:00 +0300

This work the matically models the processes of direct energy deposition (DED) 3D synthesis. The current level of scientific and technological developmentdem and sthe application of metal sandalloys with high strength, physical, and mechanical properties, operatingin aggressiveen viron ment satvarious temperatures and loadsin rocket and space technology. There fore, obtaining functional products from such materials with minimal time spenton design refine mentand product manu facturing becomesparticularly important. The most promisingmethod for rapid for ming and prototyp in gof product sisvolumetric (3D) syn the siswith coaxiallaserpowder deposition. This technology allow sfor the creation of parts of virtu allyany complexity with highprecision. Additionally, the material of parts manu facture dbycoaxia llaserpow derde position technology exhibits physical and mechanical properties comparable toor exceeding those of traditional technologies. Importantly, 3D syn the siswith laser powderde positionen ablesrapid material composition changesby in troducin gvariou spowdersin to the melt. This facilitates the development of hybrid orgradient metal composites. Considerable attention ispaid to industrial and scientific developments of 3D synthesis technology with laser powder deposition and it simple mentationin industry. However, dueto the complexity of the seprocesses, the physicsinvolved are not sufficiently understood, and the optimization of parameters fore achtype of equipmentis mostly empirical. Developing a ma the matical mode lof the energy balance of the coaxial nozzle laser powder deposition process willallow determining the main parameters of powder delivery systems, inertgas, and laserradiation sources for establishing directmetal powder deposition. The application of this mathematical model will practically help production personnel inselecting the necessary equipment and determining its parameters.

ANALYSISOFTHEPRACTICEOFUSINGMACHINELEARNINGMETHODSTOMODELTHETRAJECTORIESOFSPACEOBJECTS

V.V. Strembovskyi, A.Yu. Dreus (Author) — Mon, 10 Jun 2024 00:00:00 +0300

Earth's orbit, the development of effective methods for motion control and forecasting is an urgent problem.Currently, many industries, including aerospace science, are actively implementing the latest research technologies based on statistical analysis, artificial intelligence, and machine learning.The article discusses modern approaches and achievements in the field of using machine learning methods to analyze and predict the trajectories of space objects, in particular, when entering the atmosphere. Strategies for rapid generation and modification of optimal low-thrust flight trajectories are analyzed. An overview of the use of neural networks, regression methods, deep learning, etc. is given. Their effectiveness in various scenarios, taking into account the environment and potential hazards, is investigated. The components of ensuring space operations for the sustainable use of outer space are considered. Examples of the use of adaptive control methods and trajectory planning strategies to minimize the risk of collision of objects in space and optimize active debris removal missions are also given. Strategies for planning and controlling maneuvers of hypersonic aircraft at the stage of entry into the atmosphere are presented. The experimental results are analyzed, and the effectiveness of the developed models is tested on real data, which makes it possible to draw conclusions about their potential usefulness in practical applications. The results of the analysis provide a scientific basis for the selection and implementation of machine learning technologies in the practice of designing space object control systems and mission planning.

IMPROVING THE MASS EFFICIENCY OF THE HIGH-PRESSURE PUMP POWER VESSEL

O. Bondarenko, Y. Tkachov (Author) — Mon, 10 Jun 2024 00:00:00 +0300

Today, the aerospace industry is on the rise. The continuous development of additive technologies and the use of new, modern materials for 3D printing contribute to this. This development has led to even greater competition between space companies, both public and private. Each of them is trying to present something really new and unique. Our country also has such companies, for example, FlightControl Propulsion. This paper discusses the design of a power case for a turbopump unit of a liquid rocket engine. This unit plays a key role in the operation of the propulsion system, so special attention is paid to the design of such a unit. It is also very important to make such a unit not only durable but also lightweight, since the minimum weight criterion is very important and fundamental in rocketry in general. Such structures must withstand high pressures and remain reliable. Additive manufacturing significantly reduces the time for manufacturing certain parts and assemblies, and also provides almost unlimited possibilities in the geometric shapes of products. In fact, what was difficult or impossible to produce using classical methods is now available. Additive manufacturing already has many manufacturing technologies, and in this paper, we consider a unit manufactured using SLM (Selective Laser Melting) technology. The paper presents a structured algorithm for topological optimization, precisely by steps. The main principle of the topological optimization method SIMP (Solid Isotropic Material with Penalization) is presented. The numerical modeling of the stress-strain state for the variant of the original structure was carried out using the finite element method (FEM) in the CAE (Computer-Aided Engineering) system, a computational finite element mesh was built, and the strength margins of the structure were determined. After the topological optimization, the final design was determined and the stress-strain simulation for the optimized design was again performed. This design of the pump power casing was manufactured and successfully passed all the necessary tests.

HIGH-QUALITY KNOWLEDGE FOR EDUCATORS AS ONE OF THE DIRECTIONS OF ECONOMIC DEVELOPMENT OF UKRAINE

M.S. Khorolskyi (Author) — Mon, 10 Jun 2024 00:00:00 +0300

The future development of Ukraine's economy depends on the rate of growth of the gross product compared to the achieved level and constantly depends on scientific and technical progress, which should ensure the specified growth. For this, our generation should transfer the knowledge, experience and skills that have already been achieved to the youth - those who are getting an education, the future creators of science-intensive objects, and lay the foundation for further development, a creative approach for the emergence and implementation of new ideas, the creation of reliable new promising objects and technologies, development of new structural materials with higher technical properties, which are the source of their creation. Education seekers get knowledge mainly from teachers, from textbooks, scientific articles, from the Internet, etc., because their practical experience is not enough yet. But in some of the sources of information mentioned by me in this article, there is, in my opinion, incorrect and erroneous technical terminology, which education seekers and teachers should pay attention to and ensure the purity of the Ukrainian language. Analyzing different terminology, students will develop their creativity already today and develop and improve their knowledge. documentation. When developing one or another structural material, it is necessary to immediately study the technology of its production, to study what advantages it has over existing ones and what disadvantages it has. This will speed up its introduction into production. The article also lists the most typical widely used technical terms, indicating the correct terminology according to standardized terms or indicating their consistent use, as well as erroneous terms that have no technical justification. The article focuses attention on the fact that the correct terminology is one of the main directions of providing quality knowledge to those seeking education.

INVESTIGATION OF PHASE TRANSFORMATIONS OF AUSTENITIC STEEL BY THE METHOD OF MATHEMATICAL PLANNING OF THE EXPERIMENT IN THE PROCESS OF AGING

S. Bozhko, A. Sanin (Author) — Mon, 05 Feb 2024 00:00:00 +0200

Abstract.Processes of structure formation in austenitic steel were investigated.Using the example of the regularities of phase transformations, the possibility of significantly reducing material costs for obtaining experimental dependences of mechanical properties on heat treatment regimes is substantiated.Adequate mathematical models of physical processes during steel aging have been built.Three different methods were used to build the models: the VDSP3 cubic spline processing method of experimental results;method of processing using the mathematical package of functional programming Wolfram Mathematica;and the simplex method of Scheffé plans.A comparative analysis of the indicated methods of mathematical processing showed the suitability and possibility of their use for visualization of steel aging processes.Calculated coefficients of polynomials of the second, incomplete fourth and fourth degrees and Student's criteria.The confidence intervals of the calculations of the values of the mechanical properties of steel are determined.The stagedness of phase transformations during isothermal exposure was established and analyzed.Aging occurs in three stages: in the first stage, strengthening processes develop due to the formation of segregations of the pre-release of the strengthening phase;in the second stage, maximum strengthening occurs, particles of the strengthening phase are formed, which are coherently connected to the austenite matrix;in the third stage, due to the activation of diffusion processes and the redistribution of alloying elements, aging occurs, which leads to a decrease in the strength of steel and an increase in impact strength.The temperature-time intervals of each stage of aging are determined.Geometrical models are built in the form of contour maps of isolines of hardness and impact toughness, according to which it is quite simple to assign the regimes of thermal wear to achieve the required set of mechanical properties.Practical recommendations for obtaining the required set of mechanical properties of austenitic steel have been developed.

ANALYSIS OF THE INFLUENCE OF THE DESIGN PARAMETERS OF THE UPPER STAGE LIQUID PROPELLANT ROCKET ENGINE PUMP ON ITS CAVITATION CHARACTERISTICS

H. Nazarenko (Author) — Fri, 17 Nov 2023 00:00:00 +0200

Abstract. The phenomenon of cavitation is inherent in all vane machines, the working medium of which is liquid. With a certain combination of input pressure, flow rate, rotor speed, and the gas saturation of the working fluid in the vane machine, cavitation may occur. Cavitation negatively affects the power characteristics of the vane machines. It leads to a drop in the power parameters for the pumps and damage to their flowing parts. And also at times increases the pulsation of pressure at the pump outlet and vibration. This is especially dangerous for LPRE chambers, as the pulsation of pressure leads to the appearance of low-frequency oscillations of the chamber itself. Therefore, it is so important, even at the design stage, to determine the cavitation perfection of the LPRE vane pump and take measures to increase it.When developing the RD861K engine, high demands were placed on the power perfection of the oxidizer pump. The efficiency of the oxidizer pump RD861K should be 5% higher than that of the oxidizer pump RD861 (pump prototype).To increase the efficiency of the oxidizer pump of the RD861K engine, a number of design parameters was changed (compared to the prototype). These works were crowned with success, the required efficiency value was achieved. However, some of the taken measures had a negative impact on the cavitation perfection of the pump.This study is devoted to the analysis of the influence of the design parameters of the RD861K engine pump (which make it possible to increase its efficiency) on its cavitation properties. During the analysis, it was determined how the design parameters affect the nature of the cavitation characteristicof the oxidizer pump RD861K and RD861. It is also established how a concrete design change affects the value of the suction specific speedof the pump. In addition to the above studies, an analysis was made of cavitation characteristics of pumps operating on a gas-containing two-phase liquid. Based on the results of the analysis, the dependence of the decrease in therelativesuction specific speedof the pump on the amount of gas supplied to the inlet to the pump was constructed. The results of this study allow us to estimate the magnitude of cavitation pump failure at the design stage, depending on the design features of its flowing part when working liquid withoutgas and on the gas-liquid two-phase mixture.

POWER PROCESSING AND CONTROL UNIT OF THE EECTRIC PROPULSION SYSTEM

О.М. Petrenko, О. Alekseenko, V. Tolmachov (Author) — Fri, 17 Nov 2023 00:00:00 +0200

Abstract. The report presents the results of the development of the PPU-500, which is part of the SPS-500 electric propulsion system based on the ST-40 Hall thruster. PPU-500 contains all power supplies necessary for the operation of the propulsion system: discharge; electromagnet; cathode heater and keeper; power supplies for valves and heaters of the storage and feeding working substance, as well as a standby power supply that ensures the standby mode of PPU operation.The converter of the discharge power supply is built using a bridge topology with a phase-shifted output power control circuit. The remaining power supplies are built according to the topology of a step-down synchronous converter with current or voltage stabilization. The discharge power supply is a controlled power supply. The power supplies for the cathode heater and electromagnet current sources are. The accuracy of power supplies output parameters in not worse than 1.5%. The valves of the feeding system are controlled in order to stabilize the pressure in the receiver by periodically turning on/turning off the high- and low-pressure valves. For control the valves, signals taken from pressure sensors installed in the receiver are used. The PPU control unit ensures an accuracy of maintaining pressure in the receiver no worse than 2.5%. The control unit of the PPU is built using a microcontroller with an ARM core. It implements the functions of monitoring the condition of the program, restoring the program firmware if an integrity violation is detected, and the ability to remotely flash a new version. To communicate the SPS-500 with the on-board control system, a galvanically isolated CAN interface is used. It can be also the RS485/RS42 interface.During operation of the propulsion system, operating parameters are measured using multi-channel ADCs and DACs. The obtained data, on the one hand, is used to assess the current state of the propulsion system and control Hall thruster operating modes. On the other hand, they are transmitted as telemetry signals reflecting the current state of the SPS-500, operating mode and emerging emergency conditions of the equipment. PPU is possible to alternately control two thrusters. Solid-state switches are used to switch the corresponding power sources.Testing of the PPU-500 as part of the SPS-500 propulsion system with the ST-40 Hall thruster and a flight prototype of the working substance feeding system confirmed the technical solutions adopted. The operating efficiency of PPU-500 for the nominal operating mode of the propulsion system is 94%.

FEATURES OF THE DEVELOPMENT OF ADDITIVE MANUFACTURING METHODS IN APPLICATION TO LIQUID PROPELLANT ROCKET ENGINES

S. Sh. Vekilov, V. I. Lipovsikyi (Author) — Fri, 17 Nov 2023 00:00:00 +0200

Abstract. Modern development of additive manufacturing methods makes it necessary to seriously consider an alternative type of production for the manufacture of liquid rocket engine structures. On the one hand, additive manufacturing has a number of undeniable advantages compared to classical methods traditionally used in the rocket and space industry. On the other hand, products obtained by this method have characteristic features that must be taken into account at the early stages of design: relatively high surface roughness, the need to adapt the geometry of existing technical solutions, material properties, etc. Moreover, a full-fledged quality control system for the resulting products is currently the moment is missing, and the standardization of the production class is just emerging. It is also important to understand the direction of development of additive manufacturing, which in the future can lead to a significant increase in the characteristics of the resulting products. This paper discusses options for classifying additive manufacturing methods, provides definitions and classification of metal 3D printing methods, according to the existing ISO/ASTM 52900 standard, as well as the main features of the technology. The main advantages and disadvantages of additive manufacturing methods are considered, and a structural decomposition of the typical design of a liquid propellant rocket engine chamber is carried out. The work aimed at manufacturing structural elements for further integration into the production cycle of liquid-propellant rocket engines is considered. The work is considered, the results of which were a combination of additive technology methods, which made it possible to apply the concept of bimetallic additive production. Such products were produced without the use of complex technological equipment and belong to the product of “evolving” additive manufacturing. Based on the results of the work, it was concluded that it is possible to use additive technologies to improve the performance of new liquid-propellant rocket engine designs.

FORMATION OF PROTECTIVE COATINGS FOR PARTS OF GROUND LAUNCH COMPLEXES WITH ULTRA-DEEP MODIFICATION WITH MICROPARTICLES

B. Sereda, O. Baskevych, V. Sobolev, A. Udod (Author) — Fri, 17 Nov 2023 00:00:00 +0200

Abstract.The rapid development of the latest technologies necessitates the widespread use of metal materials with unique properties. The main factors that determine the competitiveness of manufacturers of structural materials are a number of indicators, such as the creation of new effective technologies for the production of materials with a new set of physico-chemical and mechanical properties, the reduction of energy costs for the production of new materials and protective coatings for parts of the ground launch complex. The research is aimed at studying the impact of microparticles on metal targets using mass spectrometry and metallography. Experiments revealed the formation of new elements, in particular manganese, in metal structures as a result of bombardment with microparticles. Experimental data confirmed the possibility of reactions occurring in metal targets during bombardment with microparticles. Mass spectrometric analysis revealed the synthesis of new elements that are of interest for obtaining protective coatings on parts of rocket technology for ground-based launch complexes. The study shows deep structural changes in metals under the influence of microparticles, accompanied by the destabilization of atoms and the formation of new compounds. The formation of new elements, in particular manganese, on the surface of metals after exposure to microparticles was revealed. It is shown that the processes of penetration are provided by the formation of plasma in the contact of a microparticle with a target, which occurs due to quantum mechanical effects that cause the breaking of interatomic bonds. These results open prospects for improving the operational properties of ground launch complexes. Potential applications are proposed, including the use of the effect of plasma formation in the processes of obtaining protective coatings on parts of launch complexes and the development of the theory of ultra-deep penetration of microparticles into solid partitions. The obtained results not only supplement experimental data, but also lay the foundation for new research in the field of rocket engineering and materials science. This study makes a significant contribution to science, providing a deep understanding of the physical processes involved in the collision of microparticles with metal structures. The obtained results open new horizons for rocket engineering and stimulate further research in the field of creating materials with unique properties and application in technological processes.

IMPROVING THE THERMAL STABILITY OF CARBON-CARBON COMPOSITE MATERIALS USING SELF-PROPAGATINGHIGH-TEMPERATURE SYNTHESIS

D. Sereda (Author) — Fri, 17 Nov 2023 00:00:00 +0200

Abstract.This research focuses on the development of effective protective coatings for carbon-carbon composite materials (CCСM), which are important components in high-temperature processes in aerospace engineering. The application of CCСM is limited by their sensitivity to oxidation, erosion and burnout in gas streams. In light of these limitations, our work is aimed at creating protective coatings using the method of self-propagating high-temperature synthesis, which provide increased performance and extend the service life of composites. The main task of the research is to identify the optimal compositions of powders for chromium-doped protective coatings through the SHS process. Various methods of obtaining protective coatings were analyzed, including chemical-thermal methods and methods of saturation from the liquid phase, revealing the peculiarities of the interaction of coatings with the CCСM matrix and changes in their mechanical characteristics. In addition to the classical methods of obtaining coatings, the method of surface saturation from the solid phase in an active gas environment as part of the SHS process was investigated. This method provides high-quality coating surfaces, reduction of processing time and the possibility of reaching high temperatures, depending on the composition of the SHS mixture. An important element of the research is the analysis of modern publications and research in the field of protective coatings. Special attention is paid to the problems associated with chemical interaction with the matrix of CCСM and uneven formation of carbide phases along the cross-section of the material. Experimental studies include a factorial experiment to identify the compositions of powder mixtures that provide high wear resistance. Various independent variables, such as chromium, silicon, titanium and aluminum content, are considered for their effect on the physical and mechanical properties of the coatings. The study focuses on the optimization of the parameters of thermal autoinitiation of SHS mixtures under process conditions. The regression equation for evaluating the dependences of the wear resistance of coatings on auto-initiation parameters and the content of alloying elements is given. The analysis of the research results includes the construction of three-dimensional graphic dependencies to optimize the wear resistance of coatings in the Cr-Al-Ti and Cr-Al-Si systems. Chromoalumosilicization of the coating showed better wear resistance, exceeding the wear resistance of untreated samples by 2.6-3.2 times, which allows the use of this technology for parts of aerospace equipment. It is interesting that the porous surface of coatings obtained by the SHS method prevents the penetration of oxygen into the material, contributing to the formation of oxide protective membranes, such as SiO₂, TiO₂, Cr₂O₃, Al₂O₃.

A STUDY OF IMPROVEMENT OF A TECHNOLOGY FOR OBTAINING RADIATION-PROTECTING MATERIALS FOR SPACECRAFT AND ROCKETRY SYSTEMS

S.A. Bozhko, A.F. Sanin, V.V. Bielikov, V.V. Khutornyi (Author) — Fri, 17 Nov 2023 00:00:00 +0200

Abstract. The use of commercial integrated circuits (ICs) in the electronic equipment of the spacecraft entails a certain risk. This is due to the fact that some commercial ICs are not suitable for operating conditions in space, most have a functional failure rate of about 10 krad per total accumulated dose (ie quite low), durability is not controlled from lot to lot, and reliability in extreme operating conditions is not defined. The object of development and research were the processes of interaction of materials with corpuscular radiation in a wide range of energies, and the subject of research was the shielding of electron and proton flows with energies up to 100 MeV by disperse -filled composite materials with a polymer matrix. A promising way to increase the survivability of the spacecraft by reducing the accumulated radiation dose is the use of protective materials that effectively protect the BEA from the radiation flow. The analysis of the current state of protection of radio- electronic equipment of space technology made it possible to establish that the most effective protection can be achieved by optimally combining the content of light and heavy elements in the composite material (CM). Modern research is aimed at obtaining composite materials that have the ability to weaken and disperse both light and heavy elementary particles. In the State University named after O. Honchar developed fundamentally new composite materials, which are superior in protection efficiency to those used today - metal ones, and are not inferior to the best world analogues. Preliminary results of theoretical and experimental research, including the use of computer modeling and simulation experiments on electron and proton accelerators, made it possible to draw conclusions about the possibility of increasing the complex of protective properties and prospects of the materials being created. The flow of high-energy electrons decreases by 1.4 times, and protons by 1.6 times compared to aluminum alloys. Enterprises of the space industry of Ukraine have shown great interest in the use of new protective materials. Analysis of the available information shows that the created materials are superior in operational parameters to those used today in China, Russia, Ukraine and other space countries. According to theoretical calculations, CM samples were developed, which have a higher stopping power of electrons than aluminum or its alloys, which are currently used in space vehicles in almost the entire range of the spectrum characteristic of GSO. Studies using the ELIAS linear electron accelerator showed that the obtained KM samples are more than 1.3 times more effective in terms of protective properties compared to aluminum at electron energies of the order of 2-3 MeV . There are prerequisites for obtaining an even more effective attenuation of the electron flow in comparison with the "reference" aluminum due to the variation of both the qualitative composition of the CM and its structure.

ANALYSIS OF THE METHODS AND MODELS OF MOVEMENT OF ROCKET LAUNCHERS IN THE ACTIVE SECTION OF THE TRAJECTORY

R. Keba, A. Kulabukhov (Author) — Fri, 17 Nov 2023 00:00:00 +0200

Abstract. Launchvehicles (LV) are the mainmeans of launching space craft into orbits and delivering combatunitstoenemyterritory. Eventhough there are many metho dsand models for launching space craft into Earthorbits, the issueso flaunch programe fficiency inter msofsuchcriteriaas maxim izing payloads, minimizing fuel consumption, the possibility of cluster launchin go fsatellites, the a ccuracy of hitting the enemy territory, etc. Rema inrelevant. Practical experience shows that whenlaunching a spacecraftintoorbit, the altitude accuracyis 20-30 km, and the accuracy of the final velocity in the active are areaches 100-200 m/s, which affects the deviation of the space craft'sorbits from the plannedones. Simultaneousimprovementoftheaccuracy of space craft laun chesinterms of coordinates and velo city is stillanim portant task. Mathematical models and methods for launching space craftin to Earthorbits, aswell as criteria and me thods for optimizing the movement of the boosterin the active area, areconsidered. Ananalytical review of the metho dsandmo delsused to study the movement of the LV on the active section of the trajectory, a swell as the criteria use dto optimize the movement, is carriedo ut. A classific at ion of the seme tho dsand model sismade, which canbe used to create more efficient programs for the movement of a LV onthe active part of the flightpath. Thecre ated classification allowsfor a more system atic and balance dapproach to the selection and implementation of the LV motion model, base donwhich the pitching program willbe optimized. Thepa percon sider sanap proach to solving the problem of launching a launchvehicleto a give naltitu dewith a give ndirection and speed. The paper presents the selecte dma the matical model for describing the move ment of the LV atthe active site for research, aswellasthes of tware products thata replanned to be used to solve the problem.

STRUCTURE OF THE GROUPING OF SPACE APPARATUS CONTINUOUSLY COVERING THE AREA OF THE ORBITAL GROUP WITH "HORIZONTAL OBSERVATION" DEVICES

T. Labutkina, R. Ananko (Author) — Fri, 17 Nov 2023 00:00:00 +0200

Abstract. Nowadays, observations of orbital objects with the use of orbital-based devices are increasingly relevant. The satellite system for observing orbital objects should contain two components. "The framework" of the system will be orbital groups of different heights with a supported regular structure ("Walker's constellation"); short-term "close observation" missions (necessary in the implementation of orbital service operations) must be performed by groups of spacecraft that are formed from the "park" of spacecraft that will be created in near-Earth space. A method of initial ballistic design of a group of observing spacecraft is proposed, which provides continuous coverage of the area surrounding the observed group of orbital objects with instantaneous application zones of the observation devices installed on them. Observing space vehicles implement "horizontal" observations (the axis of symmetry of the instantaneous zone of application of the observation device, which is assumed to be cone-shaped, lies in the plane of the instantaneous local horizon of the spacecraft). The initial ballistic design of the orbital grouping (which is part of a more complete task, which includes further refinement of the grouping structure and management of this structure), is carried out on the basis of a modification of the orbital grouping design method of full coverage of the altitude region above the Earth's surface by the application zones of orbital-based surveillance devices. The proposed method is aimed at solving the problem with a strict time limit in the process of mission execution. Calculations for the justification of the introduced simplifications and calculation examples of the application of the proposed method are given.

COMPARISON OF ANALYTICAL AND NUMERICAL CALCULATIONS OF THE STRESS-DEFORMED STATE OF THE NOSE STAND COMPARTMENT OF THE AIRCRAFT LANDING GEAR

I.S. Pozheva, T.I. Levitska, O.D. Manzhos, .V. Mitryashkin (Author) — Fri, 17 Nov 2023 00:00:00 +0200

Abstract. The object of the study is the design of the landing gear compartment of the nose strut of the passenger plane Boeing 737. The purpose of the work is to study the stress-strain state of the local zone of the compartment structure. To describe the stress-deformation state of the wall of the nose landing gear compartment, as well as to verify the local FE model, a Tymoshenko-type plate cylindrical bending model was used. An analytical-mathematical model of this structure was built for the problem of cylindrical bending of a plate on elastic supports and an analytical solution was obtained. The formulas for calculating deflections, angles of rotation of plate sections, curvature of the deflection function, moment distribution across the width of the plate, normal stresses on the upper and lower surfaces of the plate were obtained. At the stage of finding the elongation of the plates, they came to a transcendental equation with algebraic and hyperbolic functions, which cannot be solved analytically. The solution of this equation was presented numerically using the MS Excel software. Further, a comparative analysis of the obtained results of the constructed analytical model with numerical calculations, which used the PATRAN/NASTRAN and Excel software packages, was carried out. By changing the flexibility parameter of supports, not only intermediate boundary conditions can be obtained, but also conditions corresponding to hinged or absolutely rigid supports. The case with hinged supports was considered. For the calculation, a plate made of aluminum alloy 7075-T7351 with parameters E=10.6•106 psi, μ=0.33 was taken. The graphs of the distribution of the bending moment over the width of the plate, the deflection, the angles of rotation of the normal and the curvature of the plate, and the total normal stresses for both cases are plotted. The resulting calculations showed that the numerical and analytical solution with engineering accuracy can be considered identical. The methods and calculations presented in this paper can be used as a basis for the design of new aircraft, and for estimating the fatigue life of parts.

THE CONCEPT OF THE AIRLOCK MODULE OF MOON BASE

A. Pustovharov, H. Osinovyj (Author) — Mon, 11 Sep 2023 00:00:00 +0300

Annotation. The study and exploration of the Moon has recently entered a new stage and is gaining in scale. This process, which is currently being carried out by automatic interplanetary stations, will be further developed by manned expeditions, initially short-term, and later-longer ones. Eventually, a permanent human presence on the moon surface will be ensured. Moon bases will be established for this purpose. It should be noted that the role of humans in astronautics will remain crucial. In particular, this applies to conducting various activities directly on the moon surface. At the same time, the stay of people will be ensured by the sealed interior of the moon bases, and access to the surface and return will require special transitional compartments designed to connect these rooms (without depressurizing them) with the moon surface – airlock modules. The purpose of the work was to develop the concept of one of these modules – the airlock module. An analysis of the state of work on airlock modules in the world was conducted, the initial data and limitations affecting the design and characteristics of the module were taken into account, and the concept of its use was developed, in particular, the functions and equipment necessary for work on the Moon were determined. The module design is developed and its systems are described. The power consumption was estimated. The most rational arrangement of equipment and systems inside the module was selected. The design and appearance of the space suit for work on the moon surface are evaluated. As a result of the conceptual design, some characteristics were obtained and the appearance of the airlock module was formed. The means of delivering the module to the Moon are described, including an super heavy launch vehicle, a moon space tug, and a lander. Conceptual studies of the airlock module using the latest design methods, including 3D modeling, have shown that its characteristics are at the state-of-the-art level. The work carried out allows us to conclude that the airlock module of the moon industrial research base is an important and promising means of studying and exploring the Moon.

THE SECURITY TEMPERATURE CONDITIONS OF THE DESIGN AERODYNAMIC SURFACE OF AIRCRAFT

D. Bondarenko, P. Khorolskiy (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. This article is devoted to high-speed aircraft, specifically to controlling surfaces such as aerodynamic controls, wings and stabilizers, which are used in the high-speed aircraft. When the high-speed aircraft moves in dense layers of the atmosphere, mostly at high Mach numbers, as a rule, the front part of the aerodynamic control is exposed to huge mechanical, thermal and dynamic strains. Heating the front part of the aerodynamic control causes the change in geometrical shape and square as well as its mass center characteristics. As a result, this leads to deterioration control of the missile, especially, it is unacceptable in the final section of the flight when the purpose of the flight has to be reached, which is determined by the final parameters of the movement. The purpose of this article is to analyze existing designs, as well, to search design, which eliminates its described disadvantages. The statement of the problem consists of the design optimization of the aerodynamic controls which are considered to criteria such as reliability, controllability, minimum mass, overall and inertial characteristics. As the reliability, control of the aircraft depends on these criteria, so optimization has to be realized with the help of these criteria. The aerodynamic control design is considered that allows using it in high-speed aircrafts, which move in dense layers of atmosphere at speeds exceeding Mach number, and its design allows improving control reliability of the aircraft and avoiding heating the front part of the aerodynamic control. Design solutions that exist in full measure do not provide the necessary efficiency. The absence of protection from thermal loads lead to decline of mass, dimensional and inertial characteristics of the control surface and actuator because it demands additional heat protection coating. Therefore, it is necessary to search optimal solutions, which eliminates these drawbacks. This article provides the comparative analysis and features of these designs, as well as outlines the main problematic issues which arise during design of aforementioned aerodynamic control design options.

AN OVERVIEW ON THE DESIGN VARIANTS FOR ORGANIZATION OF THE LIQUID FILM COOLING IN LPRE COMBUSTION CHAMBERS

S. Vekilov, V. Lipovskyi (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. New technologies always create a trend to modernize and improve existing designs with new opportunities. At present, additive technologies have one of the most significant development rates among other manufacturing technologies. For modern liquid-propellant rocket engines, there is also a general trend towards increasing the efficiency of engines, finding new technological solutions that make it possible to simplify manufacturing technology, reduce technological costs and increase reliability. In this paper, known design solutions which employ film cooling for thermal protection of the walls of the engine chamber are considered. The main ways of organizing internal cooling are analyzed, the main mechanisms that define the thermal protection of the walls of the LRE chamber are considered. An overview of the existing design variants of devices which organize internal film cooling is given. The design solutions for film cooling of both the list of the real engines RD-105, RD-106, RD-0110, RD-115, RD-119 and known patent solutions are considered. The main features of such devices are shown and the influence of some design differences on the efficiency of the film cooling is analyzed. The main characteristics defining the efficiency of the device for film cooling are given. A review and analysis of the implemented design solutions for film cooling showed that the most efficient designs use the following elements, such as a gas-dynamic redan, a profiled wall of the predetermined space, and various types of inlet and outlet slots. Each design decision is based on the results of experimental testing of the engine. All these elements of film cooling design are very dependent on the accuracy of the manufacturing technology. Capabilities of additive manufacturing allow make it possible to create new designs with stable geometric characteristics in the form of a single part. The paper considers the options for applying the SLM additive manufacturing technology to create the design of the film cooling rings for liquid-propellant rocket engines.

ON THE DETERMINATION OF THE SPECIFIC HEAT FLUX VALUE IN A PULSE DETONATION ENGINE’S CHAMBER

O. Аксьонов, O. Zolotko, O. Marchenko (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. The development of detonation engines (DE) is one of the most promising areas of rocket and space engine manufacturing. They are more efficient as compared to the liquid rocket engines and are structurally simpler. At the same time, the detonation engine chamber’s structure is subjected to much higher thermal loads. Therefore, at the development stage of the DEs, to create an efficient cooling system for the engine’s chamber, it is necessary to be able to determine the value of thermal energy, which is absorbed by the walls of the DE’s chamber. The goal of this research is to determine the specific heat flux from the detonation products towards the walls of the pulse detonation engine’s (PDE) chamber. The task of the work is to establish the methodology for calculating the values of the specific heat flux transmitted to the walls of the PDE’s chamber. The main tools for solving this problem are the method of mathematical simulation using computational fluid dynamics (CFD), and the method of regression analysis. The main results of this study: the possibility to utilize the well-known Ievlev methodology to determine the convective specific heat flux for the PDE’s chamber was analyzed; it was shown that for the conditions of the PDE’s chamber, the Ievlev methodology calculation results differ significantly from the experimental data, which can be explained by the presence of a clearly pronounced non-stationary nature of the detonation process; it was proven the utilization of the Viegas formula to obtain the values of the convective specific heat flux for the PDE’s chamber gives better results as compared to the known experimental data and the results of the mathematical simulations; it was also demonstrated that the average integral value of the specific heat flux, determined by the described methodology, can be used to calculate the thermal state of the PDE's chamber. Conclusion: a methodology for calculation of the specific heat flux value for the pulse detonation engine's chamber was proposed. The obtained calculation results are in good agreement with the results of mathematical simulations and known experimental data. The described methodology can be used in the design of cooling systems for the pulse detonation engine’s chambers.

THRUST VECTOR CONTROL OF SOLID ROCKET MOTORS FOR TACTICAL MISSILES

M. Bondarenko, V. Gabrinets (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. Currently, operations involving various types of missiles have become particularly important in combat actions of different scales. At the same time, the significance of countermeasures against such missiles is increasing. To successfully accomplish combat tasks, it is necessary to anticipate and effectively counter various measures of a probable enemy when using solid-propellant tactical missiles. One of the promising approaches is trajectory manipulation of the missile at different stages of its flight using thrust vector control systems of the solid-propellant engine. This paper examines various methods of thrust vector control for tactical missiles during the initial stage of flight with the aim of countering enemy air defence systems. The described methods include vector control using automatic control means, programmed thrust vector control, internal thrust vector control, and hybrid thrust vector control. Each of these methods has its advantages and disadvantages, opening up wide possibilities for further technical improvement. Different thrust vector control methods can be used depending on the battlefield situation and specific flight segment. The application of these methods allows increasing the manoeuvrability and unpredictability of missile movement, complicating the tasks of enemy air defence systems, and enhancing the probability of successful mission completion. Meeting the stated requirements is a priority in modern conditions, making further work in the mentioned research directions promising. Common recommendations for choosing a thrust vector control method during the initial stage of flight include analysing the characteristics of enemy air defence systems, assessing potential threats, and selecting an optimal control strategy. The conclusions of this study can be utilized for the practical application of relevant thrust vector control methods for solid-propellant tactical missiles in real combat conditions. Enhancing the understanding and effective utilization of these methods will contribute to improving strategies and tactics in combat operations and help gain an advantage in conflicts with probable adversaries/

THE APPLICATION OF THE EXTENDED CELLS METHOD TO SIMULATE THE FLOW OF COMBUSTION GASES IN THE LPRE CHAMBER

I. Dubrovskyi, V. Bucharskyi (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. The numerical modeling of the process of two-dimensional axisymmetric flow of combustion gases in the chamber of a liquid rocket engine is considered in this study. In general, when solving such problems, meshes are used which lines coincide with the boundaries of the computational domain. However, an alternative solution is proposed here, which is to apply the extended cells method. It allows using rectangular Cartesian grids, which lines do not coincide with the boundaries of the computational domain, without reducing the stability of the numerical solution due to the fractional finite volumes. This also simplifies the setting of boundary conditions in such volumes. The advantage of the proposed approach over the generally accepted one is the absence of the global geometric transformations during the entire modelling process, which leads to a reduction in its duration. To perform the numerical modelling, an inviscid ideal compressible gas of constant chemical composition was chosen as a basic model of a continuum. It is described by a system of the unsteady Euler equations in integral form, which was closed by the Mendeleev-Clapeyron equation of state. For the numerical solution of this system, the finite volume method was used with the reconstruction of the flow parameters by the WENO algorithm of the third order of accuracy. The solution of the Riemann problem was carried out using the Lax-Friedrichs relations. Time integration of the system of equations was performed using the explicit Runge-Kutta method of the third order of accuracy. All calculations were carried out on a uniform rectangular Cartesian mesh, which lines did not coincide with the boundaries of the computational domain. The results were compared with the solution of the same problem using the ANSYS Fluent on an unstructured mesh coinciding with the boundaries of the computational domain. The value of the relative error obtained as a result of comparing both solutions did not exceed 0.05.

CHANGE IN THE CAPILLARY HOLDING CAPACITY OF CAPILLARY INTAKE DEVICES THAT ENSURE FUEL CONTINUITY AS A RESULT OF LONG-TERM SERVICE LIFE

O. Minai (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. Progress in space exploration largely follows the path of creating and launching new reusable spacecraft, extending the life of functioning (artificial earth satellites of telecommunications), as well as expanding the existing one (space stations) and creating a new space infrastructure, its maintenance and operation. At the same time, liquid fuel propulsion systems are used and, obviously, will be used on most spacecraft in the coming decades. In this regard, an increase in fuel reserves in orbit, an increase in the service life and repeated use of spacecraft leads to a further increase in the requirements for storage and supply systems for liquid rocket fuel components, including the means of capillary ensuring fuel continuity. At the same time, the capillary means for ensuring the continuity of the fuel and their functional elements must be operable with a large number of “filling – emptying” cycles (100 or more) and with a long active period of operation in weightless conditions (15 or more years). The article presents the results of a long-term study of the influence of a long period of the presence of the main functional elements of capillary means of ensuring fuel continuity - mesh phase separators, in the components of liquid propellant N2O4 and (CH3)2N2H2 and under their vapor, on the change in capillary holding capacity of nets. The value of its decrease during 31 years is determined. The analysis of the main factors that influenced the change in the capillary holding capacity was carried out: uniform corrosion damage to the structural material of the grids, changes in the value of the contact angle of wetting the fuel with the material of the grids. The results obtained make it possible, when designing capillary means to ensure fuel continuity, to accurately predict the maintenance of operability of mesh phase separators after their long stay in chemically aggressive fuel components. which guarantees the possibility of accident-free multiple launch of the propulsion system of the spacecraft in zero gravity during a long period of operation.

PARAMETERS OF THE ST-40M HALL THRUSTER WITH INCREASED POWER DISCHARGE SUPPLY

O. Petrenko, A. Troyan, V. Pererva (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. The article presents the results of experimental investigation of the ST-40M Hall thruster modification developed by the Space Electric Thruster Systems (SETS). The thruster used a new filament hollow cathode with an emitting insert made of lanthanum hexaboride (LaB6). The use of a new hollow cathode made it possible to study the thruster’s parameters in the discharge power range of 300 – 550 W. The investigation was carried out using a stabilized voltage supply as a discharge power supply. As a result of experimental investigation, the current-voltage characteristics of the discharge in the accelerating channel of the thruster were obtained at fixed values of the anode’s mass flow rate of the working gas - xenon. The experimental dependences of thrust on the anode’s mass flow rate of the working substance and the discharge voltage, as well as the dependences of the specific impulse and thruster efficiency on the discharge voltage, are obtained. Experimental studies have shown that with a change in the discharge voltage in the range of 250 – 400 V and a change in the mass flow rate of the working gas in the range of 0.9 – 2.2 mg/s, the thruster provides a thrust value of 12 – 33 mN, a specific impulse value of 1200 – 1800 s, and the maximum value of the anode’s efficiency is 48 – 52%. The article also contains oscillogramsillustratingtherepeatedprocessofthethrusterstarting. Experimentalinvestigationofthemodified thruster ST-40M with the new hexaboride hollow cathode showed a significant improvement in thruster parameters compared to the prototype parameter before modification. In the process of experimental investigation, it was found that in some modes of the thruster operation, significant fluctuations in the discharge current occur, which led to a significant decreasing in the thruster parameters. For a more accurate clarification of the nature and parameters of the discharge current oscillations, it is necessary to conduct additional studies. The obtained experimental parameters of the modified ST-40M thruster made it possible to determine the values of its optimal parameters for various space missions.

МETHODOLOGY FOR DETERMINE OF THE MESH BUBBLE POINT PORE DIAMETER WITH DEFORMED WEAVING STRUCTURE

M. Pozdnyshev (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. Metal woven meshes with square cells are the main working element of capillary liquid-gas phase separators. Capillary phase separators are used in spacecraft tanks to hold fuel in designated tank locations under space microgravity conditions. Separation of liquid and gas on meshes occurs due to the action of surface tension forces on the phase interface inside the mesh cells. It is possible to reduce the size of the cells of industrially produced nets by means of the method of deformation of the structure of weaving their fibers. The purpose of the work is to develop a methodology for calculating the bubble point diameter of meshes with a deformed weaving structure. A methodology for calculating the bubble point diameter of meshes with a deformed weaving structure has been developed. The developed methodology uses mathematical models that take into account the type of mesh weaving (plain, twill), the angle of interweaving of the mesh fibers and the marginal angle of wetting of its surface with liquid. Also, the methodology uses an algorithm for taking into account technological errors when making the mesh. Due to the developed technique, graphical dependences of the bubble point diameter of meshes with square cells of micron sizes, manufactured industrially, on the angle of interlacing of their fibers due to deformation were obtained. The resulting methodology and dependencies can be used in the design of capillary phase separators in the fuel tanks of spacecraft, as well as in the design of capillary devices of other technical systems, which include meshes with a deformed weaving structure, as well as non-deformed meshes with square cells, such as heat exchangers, filters, mixers, chemical reactors, etc. The scientific novelty of the obtained results lies in the development of a new algorithm for calculating the bubble point diameter of meshes with a deformed weaving structure. The resulting algorithm takes into account the type of net weaving (plain, twill), the influence of the edge angle of wetting of the net material and fuel, as well as errors in the production of the meshes.

PROSPECTS FOR THE DEVELOPMENT OF PRODUCTION TECHNOLOGIES ENGINES USING NON-METALLIC MATERIALS FOR LIGHT ROCKETS

A. Dobrodomov, Y. Tkachov (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract: The current need for the design of lightweight rocket launches to efficiently deploy nano- and micro-satellites into orbit requires the active development of new technologies, particularly in the field of engines. One possible direction is the creation of uncooled combustion chambers made from non-metallic materials, such as ceramic matrix composites, carbon-carbon composite materials, carbon-based structural materials, metal matrix composite materials, polymer composite materials, and aerogels. The utilization of these materials has the potential to significantly reduce the weight of rocket engines and decrease launch costs. The article thoroughly examines the aforementioned groups of materials that can be used in the production of non-metallic combustion chambers for rocket engines. The research aims to identify priority areas for further investigation and address practical tasks necessary for the successful development of technology for manufacturing non-metallic combustion chambers without the use of cooling systems in liquid rocket engines, particularly for utilization in lightweight launch vehicles. In terms of space technology development, detailed research in this area is extremely important. Considering the growing interest in small satellites, efficient launch and deployment into orbit are key factors for the advancement of space exploration. The use of lightweight rocket launches with non-metallic combustion chambers opens up new prospects for rapidly, efficiently, and economically launching nano- and micro-satellites into orbit. This will contribute to the further expansion of possibilities in space research and the application of this technology in various fields. General trends in space technology development encompass an increasing demand for the precise and efficient deployment of nano- and micro-satellites into orbit. Existing launch systems often have limited payload capacity and high costs, making the scalability of space missions challenging.

DEVELOPMENT OF TECHNOLOGY FOR MODIFICATION OF CAST ALUMINUM ALLOYS WITH NANOCOMPOSITIONS

N. Kalinina, A. Davydyuk, N. Tsokur, T. Nоsova (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. The research material were aluminum alloys AL9, AL4, AL4S, AL4D of the Al-Si system. The purpose of this work is to develop a technology for modifying the AL9 alloy. The "body" made of cast aluminum alloy was chosen as the object of the study. In the course of the work, the structure and properties of cast aluminum alloys were studied. The state diagram of Al-Si, physical and mechanical properties of silicon carbide were studied. AL9 alloy was selected for the manufacture of the pump housing, modification of the alloy was proposed in order to improve the mechanical properties. The structure and mechanical properties of the modified alloy were studied. The complex of research conducted confirmed the modifying effect of silicon carbide in the Al melt, the proven technology of introducing SiC into the melt, and the amount of SiC was optimized. In the modified blanks, grinding of the grain and improvement of the properties of the alloy have been achieved. For aluminum alloy AL9, the choice of SiC as a microalloying and modifying element is justified from the point of view of the correspondence of its physicochemical nature and the properties of aluminum-based alloys. Silicon carbide powder with a fraction of up to 100 nm served as the selected modifier of AL9 aluminum alloy. Studies have established the grinding of the grain and structural components of the modified alloy in comparison with the original one. With the help of metallographic analysis, the processes during modification were investigated. The establishment of the technology of introducing silicon carbide into the melt and the temperature-time parameters of the heat treatment of the blanks made it possible to obtain a dispersed structure and a high complex of mechanical properties of the cast aluminum alloy AL9. The use of nanodisperse compositions of SiC and ZrC up to 100 nm in size as modifiers of cast aluminum alloys of the Al-Si system is proposed and theoretically substantiated. Correspondence of the crystal-geometric structure of carbide-class nanomodifiers with respect to the aluminum alloy matrix was established. The conducted analysis showed that SiC carbide class modifiers have a face-centered cubic lattice in accordance with the face-centered cubic lattice of aluminum alloys. This meets the basic requirements when selecting modifiers

IMPROVEMENT OF THE ULTRASONIC METHOD OF CHECKING WELDED JOINTS OF PRODUCTS MADE OF POWDER MATERIALS MADE BY 3D PRINTING

P. Kiselyov, S. Klymenko, O. Kulyk (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. The analysis of existing methods of quality control of welded joints of products made by additive 3D printing technologies during the development of their manufacturing technology showed that in order to obtain an effective production technology and optimize the initial component composition of the material, it is necessary to conduct a quality assessment after each technological process. Unlike X-ray control, ultrasonic control is absolutely safe for people and the environment, and it is also much cheaper and easier to implement tests by a non-destructive control method. Currently, additive technologies are increasingly being used in the production of products for various purposes. According to the range of materials used in additive technologies, metals and alloys are the most practically significant and at the same time problematic from the point of view of obtaining quality products from them. This is due to the fact that products made of metals and alloys, along with requirements for the accuracy of geometric dimensions, almost always have requirements for a set of properties: physical, mechanical, chemical and operational. With regard to additive technologies, the solution to this problem is connected with overcoming two main problems - the need to obtain high-quality metal raw materials and to achieve high temperatures of its melting in order to form a monolithic crystalline structure of products. These technological connections by the method of welding of products produced by additive methods are designed to realize the potential opportunities laid down by these factors to achieve the necessary properties. Inspection of welding joints is a mandatory stage of any welding work. Thanks to careful inspection, it is possible to detect obvious and hidden defects, which will further affect the quality and durability of the entire metal structure. Of course, it is possible to assess the quality of the weld with the naked eye, but it is necessary to ascertain the fact of the presence of penetration (full penetration) using non-destructive methods. The quality of the alloy of the welded joints strongly affects the strength of the structures of the vessels operating under pressure. The non-compliance of welds with the specified characteristics leads to the destruction of structures with catastrophic consequences, the same applies to systems working with vessels and pipelines under pressure. Therefore, after welding work, the finished product must be subjected to testing and control for the detection of defects in welded joints. With the help of visual control, we will not be able to detect internal cracks and fail to cook. Therefore, it is important to know additional methods of quality control.

DESIGN AND TECHNOLOGY SYSTEM FOR DEVELOPMENT AND OPERATION OF ULTRALIGHT SUBORBITAL ROCKET COMPLEXES

O. Kulyk, A. Sanin, V. Solntsev, K. Sukhyy, A. Zaichuk, I. Karpovych (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. Vehicles are called suborbital if they either move along a ballistic trajectory with a flight velocity sufficient to reach altitudes of up to 100 km or more, but insufficient for becoming an orbiter, or fly to altitudes of 100 km or more strictly vertically, but do not become artificial satellites of the planet, even if they reach sufficient velocity at some point. In both the first and second cases, this will be considered a space flight if its height exceeds 100 km (the Kármán line). Despite the active development of the suborbital rocket science in the world as a means of solving many scientific and technical problems in the space and defense industries, scientific research and engineering education, the development of suborbital rocket science in Ukraine has so far remained, at best, at the level of achievements of the 1960s and 1970s and has been supported by numerous amateurs. This article presents the results of the creation and development of a design and technological system for the development and operation of ultralight suborbital rocket systems as the basis for the creation of new models of domestic space rocket systems, rocket and missile weapons systems, the development of innovative technologies in the field of rocket science in general, practical training of highly qualified specialists for the space industry. This paper presents structural and layout diagrams of the developed suborbital rockets, design and technological solutions for the creation of on-board radio-electronic equipment and rocket engines, design modeling, bench and flight tests. The presented design and technological system is already used today at Oles Honchar Dnipro National University for comprehensive practical training of specialists in the field of creation and operation of rocket technology and missile and rocket weapons.

INVESTIGATION OF THE INFLUENCE OF THE ROUGHNESS OF THE SURFACE OF CARBON PLASTIC ON THE HERMETICITY OF DIFFERENT JOINTS IN SPACECRAFT ROCKET TECHNOLOGY

O. Litot, T. Man’ko (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Annotation. The article is devoted to the issue of ensuring the tightness of a detachable flange joint made of carbon fiber, which operates in a cryogenic environment. When designing parts from a composite, the tasks of designing, creating a material and technology for their manufacture are simultaneously solved. Based on this feature of composites, the perfection of manufacturing technology is one of the most important features that determine the appearance of the entire structure. Thus, in order to obtain products with a high coefficient of weight efficiency and meeting the requirements used in the design of rocket and space technology, it is necessary to develop and constantly improve manufacturing technology. In the rocket and space industry, polymer composite materials, and primarily сarbon fiber reinforced polymer, are widely used in the manufacture of load-bearing elements, heat-resistant panels and sealed shells, the operation of which requires high parameters of specific strength, temperature stability and tightness. The above parameters must be ensured with a long-term influence of the propellant components of the launch vehicle. The design of detachable connections significantly affects the tightness аж a cryogenic pipeline. This is due to the high difference in the coefficients of linear thermal expansion of the materials of the elements that are in contact, the seal material, as well as the roughness of their surface. So, the use of сarbon fiber reinforced polymer is really done by high indicators of the pet's softness and hardness, which allows minimizing the mass of more details to shape the shape of the body wrap. Much attention is paid to the problem of forming a high-quality surface of сarbon fiber reinforced polymer, including complex profiled surfaces, excluding machining of the part. In this Works, experimental designs of a detachable flange connection of a cryogenic pipeline with a capacity of Ø146mm made of carbon fiber were made. The effectiveness of the adopted design and technological solutions was confirmed by leak tests with liquid nitrogen and gaseous helium. An assessment of the results obtained and conclusions on the work done are presented.

WAYS OF IMPROVING THE TECHNOLOGY OF MANUFACTURING ELEMENTS PHOTOELECTRIC POWER PLANTS

O. Marchenko, O. Ponomarov, O. Zolotko, O. Aksonov (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. The increasing interest in renewable energy sources is driven by environmental concerns and the limited availability of traditional resources. Among the various alternative and eco-friendly sources, semiconductor photovoltaic converters (PVCs) hold a prominent position. These converters facilitate the direct conversion of solar radiation into electrical energy, offering several advantages over conventional sources. PVCs benefit from an abundant raw material resource in the form of solar radiation, which is virtually unlimited. They are relatively easy to manufacture and maintain, boasting durability due to the absence of moving parts and friction. Moreover, PVCs are environmentally friendly, as they operate without emitting pollutants. In Ukraine, the average solar radiation during a typical daylight day amounts to approximately 4 kWh per square meter, with summer values reaching 6-6.5 kWh. This corresponds to an annual average of 1500 kWh per square meter, equivalent to a staggering 15 billion cubic meters of conventional fuel. Such solar resources present significant opportunities for sustainable energy generation in the country. Nevertheless, the widespread adoption of PVCs faces challenges primarily due to their high cost. However, cost reduction strategies can be implemented through the use of affordable materials and simplified designs that optimize the composition of semiconductor layers. Traditionally, PVCs relied heavily on expensive monocrystalline silicon, making them primarily suitable for space applications. Fortunately, advancements in manufacturing technologies and the exploration of alternative materials offer the potential for cost reductions and broader PVC implementation. The development and application of innovative manufacturing techniques, along with the design of efficient structural components for solar energy installations, will pave the way for a more affordable, sustainable, and environmentally friendly energy sector.

MODELING OF REINFORCING FIBER FEEDING UNIT FOR 3D-PRINTING OF COMPOSITE FIBER-REINFORCED PARTS IN AVIATION AND AEROSPACE VEHICLES

M. Sirenko, O. Karpovych (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. The development and improvement of means of additive production and manufacturing of products is also used in aviation and rocket and space applications. As new demands to parts arise, new manufacturing technologies are developed, and existing ones are being improved. One of the types of improvement of the existing and well-known FDM/FFF 3d printing technologies to improve the properties of parts is reinforcement with composite fibers. Among most types of reinforcement, continuous fiber reinforcement is the most effective and promising, namely, towpreg reinforcement and the use of a separate nozzle for adding reinforcing fiber, since these types allow you to obtain products for use in aerospace vehicles with controlled characteristics. But there is a problem of undefined parameters of substances added to reinforcing fibers in the process of their manufacture, which introduces unknown variables into the study of the parameters of the obtained parts. The purpose of this work is to develop a model of a feeding unit for pure untreated fiber, to work out techniques and features of fiber behavior in supply tracts. Literature and news about 3d printers that allow reinforcement of parts were analyzed, a reference model of the feed unit was created, and tests were conducted on carbon and basalt fiber. Based on the results, an improved model of the supply unit was created, tests were conducted, and the optimal parameters of some parts and parts of the supply unit were determined for the given initial data. The characteristics of the behavior of pure, untreated fiber during feeding were determined, data were obtained for the development and design of the fiber feeding node, which will be directly installed on a 3d printer. Also, the possibilities of part manufacturing for such feeding units with FDM/FFF 3d-printing were analyzed. As a result, some parameters of parts were estimated, such so reliable manufacturing of these parts with 3d-printing wouldn’t have a negative impact on overall performance of feeding unit.

MODELING OF THE PROCESS OF PROCESSING WITH AN ABRASIVE AIR JET OF THE WORKING SURFACES OF THE BLADES OF CLOSED-TYPE MONOWHEELS OBTAINED BY THE ADDITIVE METHOD

Y. Shashko (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. The use of additive technologies for the production of parts in aircraft and rocket engineering is becoming more and more widespread every year, as this method has a number of significant advantages compared to traditional technologies such as stamping, casting and machining, and is considered an alternative manufacturing method. However, additive technologies unfortunately have a significant and serious drawback, namely obtaining the required roughness and quality of the surface of the products regardless of their spatial location. The use of this method makes it possible to manufacture various parts of rocket and space technology, primarily turbine impellers with closed blades on one type of equipment in a much shorter time. However, despite the significant advantages of additive technologies, the problem of roughness and ensuring the final quality of the surface remains relevant, regardless of the spatial arrangement of the elements of the part. The reason for this is the limited access of traditional cutting tools such as cutters or grinding heads. A promising method of processing the working surfaces of closed turbine blades is abrasive jet processing (blasting). The correct choice of technological modes can guarantee ensuring the results of inkjet processing. However, the need to take into account a significant amount of input data, namely the parameters of the equipment, the abrasive jet, the physical and

mechanical properties of the material and the shape of the processed product surfaces, as well as the lack of clear recommendations and technological data significantly complicate the process.

The goal of the task is to model the jet processing of closed-type monowheel blades using the ANSYS CFX finite element analysis software system. This article presents the results of numerical modeling of the surface treatment of closed turbine blades and the identification of technological factors affecting the surface roughness and quality of the compressed air environment on samples made of Inconel 718 alloy.

The obtained results will be used in the development of a real technological process of processing the flow parts of the closed type blades and further introduction into production.

USE OF MICRO-SERVICES ARCHITECTURE AND CONTAINERIZATION FOR THE FAST DEVELOPMENT AND TESTING OF THE CUBESAT NANOSATELLITES SOFTWARE

O. Liubimov (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. CubeSats as a sub-class of nanosatellites have become a game-changer in the industry of scientific research and exploration of the new space technologies. Their cost effectiveness, relative ease of manufacturing, and predicted lifecycle are the main factors of success, leading to roughly 2280 nanosatellites being put on the Earth’s LEO. However, many issues still arise in regard to the effective development, testing, and successful mission control of the CubeSats. The authors of the article suggest the combination of well-known software development processes, design paradigms, patterns, and techniques, that are creating a new way of making CubeSat software development as flexible and as easy as possible. The very first part of the research suggests the outlook on modern software development processes and their evolution over the last years. The second part of the research looks into virtualization and containerization principles as the architectural response to complex software development. The third and fourth parts of the research concentrated on the selection and proper testing of the container execution engine and its performance with the most common algorithm used in embedded software development. Via the porting and proper performance test of the WASM3 WebAssembly interpreter, the authors provide valuable research in regard to the practical use of micro-services, and containerization in the CubeSats. For the sake of the usefulness and completeness of the porting and performance testing – the authors suggest the most-known STEM platforms as the test environments. Concluding the research by the practical porting and testing steps, and found limitations of the containerization, the authors come up with a newly defined concept of so-called Software Defined Satellites. Such a concept could help the industry to minimize risks in reusing the software, perform several missions on the same CubeSat spacecraft, and thus, drastically decrease the cost of CubeSats launches.

USE OF OPEN-SOURCE COTS/MOTS HARDWARE AND SOFTWARE PLATFORMS FOR THE BUILD UP OF THE CUBESAT NANOSATELLITES

O. Liubimov, M. Liubimov (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. CubeSats as a sub-class of nanosatellites have become a game-changer in the industry of scientific research and exploration of the new space technologies. Their cost effectiveness, relative ease of manufacturing, and the predicted lifecycle are the main factors of success. Having such popularity in mind – many vendors, student teams and enthusiast started to build their platforms to offer reuse and faster buildup of such satellites, introducing so-called COTS/MOTS approach of the satellite’s construction. However, looking into statistics – only 2.5% of the launched satellites were able to full perform their mission, and almost 25% just failed. Partially, the key problems are in the area of using non-radiation hardened electronics as the CubeSat idea is to use commercial (or at utmost automotive) components. Authors of the article provide a holistic view on the existing hardware and software platforms that are currently available as COTS/MOTS solutions, as well as their capabilities. Part of the research was done in the area of the available software frameworks, as the modern software has rather high cyclomatic complexity and often it is exactly software components that make CubeSat mission at risk. Software related frameworks are compared via the use of newly introduced by the authors multi-factor ranking model (FMCSA). At the same time the article raises the cross-country problem of the creation and use of the Ukrainian platform for the CubeSats. Authors propose a solution for the creation of the part of the CubeSat platform as the starting point and it is an On-Board Computer (OBC). The idea is to design an OBC that can solve the big portion of the known issues of the CubeSat hardware and software with the major stress on the hardware issues related to the Single-Event Upset (SEU) and Single-Event Latch Up (SEL), without moving to the radiation tolerant semiconductors. Proposed in the article solution combines the selection of the modern central processor, that is industry recognized, availability of the software solutions for it, as well as the power-domains control principle that allows to minimize the potential harm of the SEU and SEL radiation-driven events.

TEORETICAL-EXPERIMENTAL COMPARISON OF THE MODELS OF ADDITIVELY MANUFACTURED SWIRL INJECTORS BASED ON THE HYDRAULIC TESTING RESULTS

S. Vekilov, V. Lipovsikyi, R. Marchan, A. Lohvynenko, R. Pustovoy (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Annotation. Recent success in development of the technology stipulated the appearance of advanced additive manufacturing aimed to shift conventional subtractive manufacturing from its position in the engineering field. Thus, for LPRE manufacturing there is an obvious advantage of additive manufacturing in terms of ability to produce single-piece parts with complex geometry must be seriously considered. In the modern world there is a constant competition between complex engineering decisions and cost efficiency of the production on the market of liquid propellant rocket engines. On the one hand, mixing head is one of the most demanding parts of LPRE in terms of designing. On the other hand, the earliest stage of its development starts with the choice of a type of mixing elements to ensure combustion stability, efficiency, and overall production cost [1]. Typically this step requires advanced knowledge in the real characteristics of produced injectors, or extensive experimental study should be carried out otherwise. In this work a problem of determining the characteristics of additively manufactured swirl injectors is considered. Laser Powder Bed Fusion [10] was chosen as a production method using Haynes 230 as a main material. A range of the swirl injectors with varied geometrical parameters was manufactured. Hydraulic testing was carried out in a wide range of Reynolds numbers for determining flow characteristics. Typically, discharge coefficient and spray angle are the desired values to know. Sauter mean diameter and film thickness were not studied due to lack of equipment. Considering a problem of prediction of the main characteristics of the produced injectors, a review on known equations for calculation of the main parameters was performed. Comparative analysis between calculated and experimental data was carried out. Results show that there is severe discrepancy between calculated values of characteristics of injectors and experimentally obtained data for additively manufactured swirl injectors. Even though the conducted study gives a base to form consistent conclusions of the behavior of the obtained characteristics, additional investigation is required.

AN EXAMPLE OF USING ANSYS EXPLICIT DYNAMICS TO DETERMINE THE IMPACT STRENGTH PARAMETERS OF A BULLET WITH A MULTILAYER BARRIER

O. Minai, A. Lohvynenko (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. Currently, a very urgent issue is the search for an effective type of individual armor protection for the torso of fighters – that is, body armor or plate carriers that protect against bullets and debris, which are the main causes of injuries. The authors of the article have developed a simplified engineering numerical calculation model for determining the strength parameters during the impact interaction of a bullet with a multilayer armored obstacle, which should be used as the main protective element of bulletproof vests, or plate carriers. The simulation was performed using the ANSYS Explicit Dynamics software product, which is based on a powerful calculation modulus of strength – Autodyn. The Johnson-Cook strength models, the shock adiabatic linear equation of state and the Grüneisen equation of state are applied, which have proven themselves well in solving such problems. At the same time, in order to obtain a more optimal solution to the current problem, the Lagrangian method for solving the finite element problem is applied , in which the mesh of the model and the material are rigidly connected to each other and must only move together. This method makes it possible to more accurately calculate the characteristics of the state of the media, the location of the fronts and the values of the peak pressures of shock overloads. As the main impact element, a bullet of 5.45x39 mm cartridge from the AK-74 assault rifle - index 7N10, with increased penetrating ability, which is designed to defeat enemy manpower, protected by means of individual armor protection, as well as single and group targets and other those technical means when firing at a distance of up to 600 m. A 4 – layer package is considered as a multi-layer armored obstacle: spraying N_iC_r / steel 30ХН2МА / coating AL₂O₃ / Polyamide (PA66), replaced by the closest (analogues) in terms of physical, chemical and mechanical properties from the ANSYS Explicit Materials section of the library, which contains data on the required design coefficients of deformation of materials during their destruction. The created numerical calculation model allows to develop more optimal designs and significantly reduces the time for designing the main protective element of bulletproof vests or plate carriers.

NEW PROJECT METHOD FOR CALCULATING THE MAIN PARAMETERS OF THE SOLAR COLLECTOR

V. Gabrinets, L. Nakashidze (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Abstract. A new method for calculating the design of a solar collector, which converts solar energy into heat, is proposed. It proposes to apply the substitution coefficient, which means the ratio of the heat received by the system as a result of solar radiation, to the total heat load of the entire system, that is, to take into account not only the heat losses of the solar collector itself, but also the losses of the system itself, on which the solar collectors work. This allows you to calculate the efficiency of the entire system of converting solar energy into thermal energy. A classification of systems that use solar energy with the use of a collector to generate heat is proposed. Various variants of the principle schemes of the solar collector are considered, as well as various variants of its heat-receiving surface. The influence of the design of the solar collector on the amount of heat loss is considered. The method of successive approximations is used to determine the heat loss coefficient of the solar collector. When determining heat losses, it is necessary to take into account the non-uniformity of the temperature distribution in the cross-section of the solar collector. For this, an expression for the corresponding coefficient is proposed. Reducing the heat loss of the absorbing surface is achieved by installing a transparent coating, which should transmit solar radiation well and form an air layer that acts as a thermal resistance. In addition, the coating protects the heat-absorbing element from rain, snow, hail and therefore must be strong enough. The proposed design method of calculating the solar collector allows you to obtain the following parameters: the area of the solar collector, the number of modules included in the solar collector, heat losses in the solar collector, the useful power supplied to the coolant in the solar collector, the temperature of the coolant at the outlet of the solar collector. The ability to qualitatively calculate such a basic element of a solar power plant as a solar collector is of great practical importance. It allows you to quickly and quite accurately calculate the main parameters of the entire solar energy installation (SEU) in various cases and widely used.

ATTRACTION OF INVESTMENTS IN SPACE ACTIVITIES IN UKRAINE

M. Didenko (Author) — Fri, 28 Jul 2023 00:00:00 +0300

Annotation. One of the key factors in the successful development of any sector of the economy, which largely determines its dynamics and competitiveness, is the inflow of investments. The experience of the world's leading space countries (USA, EU) shows that attracting private investment opens up significant prospects for the development of the industry. However, one of the key requirements for attracting investment is the existence of a favourable macroeconomic environment, which is unlikely to exist in the current environment. The purpose of the article is to find areas and projects that will allow attracting private investment in space activities in Ukraine. Analysis of the dynamics of the development of the global market of space services indicates about its predicted growth in the period up to 2040 [1]. At the same time, the vast majority of the amount of investment in this market is not in the “material part” (launch services, manufacturing of space vehicles, etc.), but in the sphere of satellites and service delivery. And mentioned disproportion in has a trend to increasing. In the current market situation, the most investment-friendly projects, apparently, are those, which are related to the designated market segment. Thus, one of the fastest growing areas is the provision of services related to the machine learning and the Internet of Things (M2M/IoT). The growth of this market segment is predicted by most market researchers. At the same time, today's scientific and technological progress makes it possible to transfer M2M/IoT technology to a smaller satellite platform (from microsatellite to nanosatellite). The implementation of projects of this type has a number of advantages in terms of attractiveness for investors, as the technical specification allows for their implementation in two stages. At the first stage, an already functioning system with limited technical characteristics can be obtained at relatively low capital costs. The second stage, which is the main one in terms of capital expenditures, involves increasing the coverage area, bandwidth and other technical characteristics. This model of project implementation makes it possible to start its implementation even with relatively small initial investments and macroeconomic instability.

DEVELOPMENT PROSPECTS OF 3D-PRINTING OF OBJECTS IN AVIATION AND AEROSOACE FROM POLYMER MATERIALS WITH COMPOSITE REINFORCEMENT

M. Sirenko, E. Karpovych (Author) — Thu, 23 Feb 2023 13:04:00 +0200

The development of means of additive manufacturing and manufacturing of products is also used in aviation and rocket and space technology. Additive manufacturing makes it possible to improve the mass coefficients of parts and assemblies, to give parts shapes and features that are difficult to implement using traditional production methods. The choice of new types of production is reflected not only in the improved technical characteristics of devices and flying objects, but also in their design, which adapts to the conditions of additive manufacturing of details and parts. In the absence of obstacles and limitations of traditional production methods, it becomes possible to fully use the advantages of spatial and topological optimization of parts and structures. This article examines the main features and market trends associated with the introduction of additive manufacturing and 3D printing methods with an increase in the scope of their application. Existing models of equipment present on the market were analyzed. The peculiarities of the types of reinforcement, their influence on the characteristics of the final product and the requirements for the equipment on which the parts will be printed with the appropriate types of plastics were considered. Based on these trends, the materials with the greatest potential for more mass application and the equipment compatible with these materials were analyzed. Materials with different types of reinforcement were considered and analyzed, and their characteristics and advantages were given. Based on the analysis, the recommendations on the optimal choice of material and the state of the market of materials and equipment were presented in the conclusions. Also, recommendations were given for upgrading home or amateur-class 3d printers for printing with such reinforced plastics.

ST-40 HALL TRUSTER TESTING WITH LaB6 HOLLOW CATHODE

O. Petrenko, A. Kashaba, V. Maslov, S. Oslavsky (Author) — Thu, 23 Feb 2023 13:03:34 +0200

The results of experimental investigation of the ST-40 Hall thruster operating with a heating hexaboride cathode are presented. The readiness of the heating hollow cathode to the thruster start was assessed by reducing the cathode keeper voltage from the start value of 100 V to 15 ... 17 V, when an internal discharge in the hollow cathode occurred. Various cyclograms of the thruster start are considered with the definition of the purpose of the cyclogram, which ensures reliable thruster start. Three cyclograms of the thruster start are investigated: with the thruster’s electromagnet coils switched on; with the coils off; without switching off the voltage at the hollow cathode keeper, which made it possible to restart the thruster without preheating the hollow cathode. The obtained cyclograms make it possible to ensure a reliable start of the ST-40 thruster when operating with a heating hexaboride hollow cathode. In the course of laboratory research, the PPU-300 power processing unit was used. It ensured the stabilization of the discharge power in the thruster’s accelerating channel and stabilization of the currents supplied to the central and external coils of the thruster. The main operating characteristics and parameters of the ST-40 thruster were obtained for three fixed values of the discharge power: 265, 281, 300 W and a change in the mass flow rate of the working substance (Xenon) through the anode unit of the thruster 0.7 ... 1.3 mg/sec. Experimental investigation of the ST-40 thruster in a wide range of parameters made it possible to determine the optimal thruster’s parameters that provide the maximum values of thrust and specific impulse for the given values of the discharge power in the accelerating channel of the thruster and the minimum discharge current. The process of the thruster’s parameters optimizing was carried out by changing the currents flowing through the internal and external coils of the thruster. In the course of experimental research, it was found that the inner coil and the serially connected outer coils can be connected in parallel and powered by a single power supply. Experimental studies have confirmed the correctness of the adopted technical solutions in the development of the ST-40 Hall thruster and the heating hexaboride hollow cathode.

AN INTEGRATED APPROACH TO SOLVING THE PROBLEM OF RELIABLE COOLING OF THE DETONATION ENGINE CHAMBER

O.S. Aksonov, O.E. Zolotko, V.V. Stolyarchuk (Author) — Thu, 23 Feb 2023 13:03:02 +0200

One of the most promising areas of development of rocket and space engine building is the development of detonation engines. However, to create such engines need to solve a number of complex technical problems. One of them is the problem of cooling the chamber, which receives high heat loads. For reliable operation of the detonation engine chamber, it is necessary to ensure the allowable temperature of the chamber wall and to prevent spontaneous combustion of the prepared fuel mixture capable of detonation. Since the detonation engine operates in non-stationary mode with a sharp change in the parameters of the chamber, one of the main tasks to create a reliable cooling system is to determine the level of heat load on the structure. One of the tools for solving this problem is the method of numerical experiment using mathematical simulation technologies. A computational experiment was performed to determine the value of the specific heat flux to the wall of the detonation engine chamber. The results of the experiment agree well with the known data of other authors. The peak value of the specific heat flux at the detonation wave front is determined. The obtained results indicate that the chamber of the detonation engine is subjected to a much higher thermal load than the chamber of the liquid rocket engine. The analysis of the possibility of using traditional ways and methods of cooling for the detonation engine chamber showed their lack of efficiency. Therefore, it is necessary to develop new promising methods and ways to cool the chamber of the pulse detonation engine. The difficult task of finding an effective system of external cooling of the rocket detonation engine chamber requires a integrated approach.

LOW POWER HALL THRUSTER ST-22 WITH PERMANENT MAGNETS

D. Voronovkyi, O. Petrenko, S. Kulagin, V. Maslov, B. Yurkov (Author) — Thu, 23 Feb 2023 13:02:37 +0200

The results of the design, development and testing of the laboratory model of the Hall Thruster ST- 22 are presented. The main attention in the development of the thruster was focused on the optimization of the magnetic field in the accelerating channel of the thruster. When choosing a constructive thruster diagram, it was proposed to use constant magnets and a non -magnetic ring in a magnetic system. The proposed constructive features of the thruster made it possible to exclude a magnetic screen from its design, which led to the simplification of the structure and reduce its mass. Laboratory tests of the ST-22 thruster were carried out when changing the discharge voltage in the range of 160-260 V, as well as with three different values of the mass flow rate of Xenon submitted to the anode - 0.4, 0.5, 0.6 mg/s. In the course of laboratory investigation of the ST-22 Hall thruster, the following characteristics were determined: current-voltage characteristics of the discharge in the acceleration channel of the thruster; the dependences of thrust and specific impulse on the mass flow rate of the working substance and the discharge voltage, as well as the value of the efficiency of the anode block of the thruster on the discharge voltage. As a result of laboratory tests, it was shown that at input power of 100 W, the discharge voltage 215 V and the working substance flow through the anode unit 0.6 mg/s, the thruster provides the thrust value of 7 mN, the discharge current of 0.47 A, a specific impulse of 950 s, and efficiency 33%. The values of the specific impulse and the thruster efficiency were given taking into account the mass flow rate of the working substance in the cathode-compensator. The thruster provides sustainable operation in the range of power consumption of 50 - 100 W and it was designed to use small spacecraft on board, which on board have appropriate electric power.

EXPERIMENTAL STUDY OF THE RANGES OF STABLE OPERATION OF CATHODE-NEUTRALIZERS FOR HALL-EFFECT THRUSTER

K.S. Shevchenko, A.T. Tsapenko (Author) — Thu, 23 Feb 2023 13:02:06 +0200

With the development of space exploration, the need for more advanced propulsion systems for spacecraft is growing. Electric propulsion systems (EPS) are the most promising for orientation and correction systems. The Hall effect thruster (stationary plasma thruster in Ukrainian and Russian literature) (HET) is one of the most efficient and promising EPS thrusters. The cathode neutralizer (cathode compensator in Ukrainian and Russian literature, hereinafter referred to as the cathode) is one of the main elements of the HET. The resource and stability of the HET operation depend on the cathode. Previously, they were limited to studying the operation of the cathode in several modes. This made it possible to find the best mode of operation. Testing more modes will make it possible to predict the nature of the HET operation with this cathode. Also, similar gas-discharge cathodes are used in thrusters with anode layer, for ion thrusters and as sources of plasma in ion-plasma technologies. A number of non-incandescent hollow gas-discharge high-emission cathodes of the same model were tested in the diode mode. The cathodes were tested without a keeper; instead of the HET anode block, its simulator was connected to the gas-discharge circuit. With the help of a vacuum system, the operating conditions of the cathode were simulated - the ultimate vacuum was not worse than 2∙10-5 Torr. Xenon was used as the propellant. To support and regulate the operation of the cathode, plant models of the system for storing and supplying the propellant, power supply and control systems were used. Voltammeters measured the discharge current and voltage. Flow meter measured the mass of the propellant supplied to the cathode. Optical pyrometer measured the temperature at the cathode near to the diaphragm. The characteristics (the dependence of temperature and voltage on current or flow rate with the fourth parameter set) of cathodes were obtained. The stability of the operation of cathodes in one mode and the characteristics of the cathodes were explored. When the current decreases, the voltage rises at first smoothly, and then a peak is observed. A shift of this voltage peak towards a lower current with an increase in consumption was observed. It is shown that the cathodes operate most stably at currents corresponding to the horizontal part of the current-voltage characteristic (from the side of high currents from the peak). The operation of a cathode with a defective emitter is demonstrated. The operation of the cathode, which was stored for a long time, therefore had changes in the emission properties of the surface of the emitter material, was demonstrated.

JOINT FORMATION PROCESSES DURING DIFFUSION WELDING ON THE COVERED SURFACES OF TITANIUM-STEEL ADAPTER

О. V. Karpovych (Author) — Thu, 23 Feb 2023 13:01:38 +0200

The article presents the results of experimental studies of joints diffusion welding on the covered surfaces of titanium alloy Ti-6Al-4V and stainless steel AISI 321. Microstructural analysis of AISI 321- Ti-6Al-4V joints and concentration curves of titanium and aluminum showed that with a decrease in welding time, the width of the transition zone of the joint decreases due to the reduction of the diffusion area on the side of the titanium alloy. On the side of steel, the concentration of titanium does not change and leads to the formation of intermetallic layers, the width of which decreases slightly. This is explained by the high rate of formation of intermetallics in welding conditions. Changing additional factors that affect the rate of formation of intermetallics, such as reducing the welding temperature and pressure, will not allow to obtain the necessary contact area and ensure sufficient activation of the surfaces to be welded for the formation of a diffusion connection between the parts. The calculated values of the diffusion coefficients are higher than the tabular volume diffusion coefficients by several orders of magnitude (103...104), which confirms the dislocation mechanism of elements diffusion in the AISI 321-Ti-6Al-4V joint, obtained by the method of diffusion welding on the covered surfaces. The strength of the joints increases with a decrease in the exposure time to a certain limit, and then increases slightly, which confirms the assumption of a high rate of intermetallics formation. The strength of welded joints is significantly lower than the strength of the base metal - stainless steel (the strength of steel AISI 321 per cut is 330-380 MPa). In order to obtain connections on the covered surfaces of titanium alloy Ti-6Al-4V and stainless steel AISI 321 with the required strength, it is advisable to investigate the process of diffusion welding through an intermediate copper layer.

APPLICATION OF DRY ABRASIVE MACHINING AND EXPERIMENTAL SELECTION OF MATERIALS FOR FINISHING OF CLOSED-TYPE BLADES

Yu. Shashko, S. Adzhamsky, S. Kazeev, R. Maksimchuk, A. Kulik (Author) — Thu, 23 Feb 2023 13:01:15 +0200

The use of additive technologies for the production of parts in aircraft and rocket manufacturing is becoming more widespread every year, since this method has a number of significant advantages over traditional technologies such as stamping, casting and machining and is considered as an alternative manufacturing method. The application of this method makes it possible to manufacture various parts of rocket and space technology, first of all, impellers of turbines with closed-type blades on one type of equipment in a much shorter time. However, despite the significant advantages of additive technologies, the problem of roughness and ensuring the final surface quality, regardless of the spatial arrangement of the part elements, remains relevant. The reason for this is limited access to traditional cutting tools such as milling cutters or grinding heads. Until now, the traditional technology for processing such parts such as closed blades has been the method of electrical discharge machining (ESM), however, this method has a number of significant disadvantages, such as: energy costs, the complexity of preparing the process, the complexity of tool manufacturing and processing implementation. The purpose of the work was to study the possibilities of using jet-abrasive processing and its varieties (blasting) and the selection of abrasive material to ensure the required quality and roughness of the surface of the blades. This article presents the results of experimental work on the study of a single short-term mechanical action of abrasive materials in a compressed air environment on material samples from the Inconel 718 alloy at certain angles of attack. The results obtained will be used in the development of a real technological process for processing the flow parts of closed-type blades and subsequent implementation in production.

IMPACT ANALYSIS OF MEMS-COMPONENTS ERRORS OF SINS ON ACCURACY OF SATELLITE LAUNCH VIA ULTRALIGHT LAUNCH VEHICLE

A.S. Smyrnov, O. V. Holubek (Author) — Thu, 23 Feb 2023 13:00:34 +0200

The article is devoted to the development of work on the study of the influence of the error of measuring instruments of a strapdown inertial navigation system built using micro-electromechanical components on the accuracy of injection a spacecraft by an ultralight launch vehicle into low near-Earth orbits up to 400 km altitude and inclination order 37,4. For two modes of operation of a strapdown inertial navigation system (inertial and inertial-satellite), using the method of factorial analysis, a study was made of the accuracy of the injection of the spacecraft, as a result of which the following results were obtained. The determining disturbing factors are revealed, the dependencies of the trajectory tubes and the limit deviations of the kinematic parameters of the spacecraft at the point of separation from the launch vehicle on the altitude of the target orbit are determined. It is revealed that the determining disturbing factors are the run-to-run bias of the gyroscope and the random drift of the gyroscope. It is shown that the trajectory tubes increase in size with the flight time and with an increase of the altitude of the orbit. The maximum deviations of the current position and absolute speed in the inertial mode were 218 km and 543 m/s, respectively. In the inertial satellite mode, these values do not exceed 132 m and 1.4 m/s, respectively. It is determined that the maximum deviations of the osculating parameters of the spacecraft orbit are: in altitude is 54 km, in inclination is 1.7, in eccentricity is 1.210-4, in right ascension ascending node is 6.9. For the inertial-satellite mode: in height is 722 m, in inclination is 0.003, in eccentricity is 2.310-4, in right ascension ascending node is 0.03. It is shown that the use of data from a satellite navigation system significantly reduces the trajectory tube and increases the accuracy of the osculating parameters of the spacecraft orbit. A comparative analysis of the spacecraft injection accuracy was carried out for two values of the inclination of the target orbit of the spacecraft 37,4 and 51,5.

ENERGY-EFFICIENT METHODS OF CONTROLLING THE ANGULAR POSITION OF SMALL SPACECRAFT

O. Grebenkina, A. Kulabukhov (Author) — Thu, 23 Feb 2023 12:59:57 +0200

A lot of attention is given to satellites' mass decreasing and ubiquitous use of micro and nanosatellites. It’s related to the progress in microelectronics devices development and significant orbital launch cost. The process of satellite dimensions reduction leads to increasing energy capabilities restrictions. This fact determines the need for improvement of control methods. The goal of the work is the development of a low-energy angular motion control method for microsatellites. Such methods include passive angular orientation and stabilization and active control with restricted energy consumption. The features of such methods were considered. The dependencies of maximum deflections angle from initial angular velocity obtained due separation from launch-vehicle in case of using gravity stabilization boom were obtained. The obtained results could be used in the gravity stabilization system design process. The guidelines for design of satellites' energy-efficient controllable attitude maneuvers were developed. The models of friction torque inside the flywheels were developed. They will increase the accuracy of computer simulation of satellite attitude control with using flywheels in impulse mode. Use of gravity stabilizer and flywheels in impulse control mode for attitude control can significantly reduce energy costs. The design of modeling guidelines were developed. They allow modeling the processes of angular motion for listed tasks. A methodical support for the method of attitude control with using flywheel at impulse mode has been created. It is allow to provide attitude control computer simulation with more accuracy using a model of friction torque and significantly decrease onboard energy consumption also.

PLANNING MANEUVERS FOR STABILIZATION THE FLIGHT ALTITUDE OF A RADAR SATELLITE USING AN ELECTRIC PROPULSION SYSTEM

A.V. Golubek, G.V. Farafonov (Author) — Thu, 23 Feb 2023 12:59:24 +0200

The article is devoted to the development of a method for planning the activation of an electric propulsion system to provide the stabilization of the flight altitude of a radar satellite in the ascending node of the orbit, taking into account the limitations of the power supply system. A method for stabilization the satellite trajectory to the nominal flight altitude has been developed. It is based on the solution of the variational problem of finding the optimal combination of an electric propulsion system burning time, the orientation of the thrust vector, and the orbital argument of the latitude of the ignition point. A mathematical model of the satellite's motion, as a point of variable mass, under the influence of the thrust forces of an electric propulsion system, the Earth's gravity and the aerodynamic drag of the Earth's atmosphere has been developed. The control program and its functionalities for the electric propulsion system have been determined. It is shown that taking into account the limitation on the burning time of the electric propulsion system leads to the need of distribution of the flight altitude stabilization maneuver into several ignitions, between which there are sections of the satellite battery charge. It is proposed for all activations of the flight altitude stabilization maneuver, except for the last one, to represent the search for parameters of the control program as a problem of maximum compensation for orbital deviation with minimal consumption of the working substance and a limitation on the electric propulsion system burning time. For the last activation - to represent it as problem of providing a given level of deviation of the orbit altitude while minimizing the consumption of the working substance. Computer simulation was carried out, which confirmed the efficiency of the proposed method. The dependences of the flow working substance mass consumption and the average number of maneuvers required to stabilize the altitude of the orbit of a satellite with a 210-5 thrust-to-weight ratio and average ballistic coefficient of 0.01 m2/kg on the altitude of the sun-synchronous orbit are determined.

SYSTEM OF AUTOMATED ACOUSTIC CONTROL OF PRODUCTS MADE OF POLYMER COMPOSITE MATERIALS

P. Kyselov, S. Klymenko, O. Kulyk (Author) — Thu, 23 Feb 2023 12:58:48 +0200

The use of glued layered and honeycomb structures in aircraft construction can significantly increase the weight efficiency of technology, ensure its acoustic strength and high reliability [1]. Virtually the entire fuselage of the Boeing 767-300 is a multi-layer glued structure. A large number of various cellular units with metal (Al-alloy, Ti- alloy, steel) and non-metallic (from polymer composites) cladding and metal (Al-alloy) and non-metallic (from fiberglass, fiberglass, polyamide paper type "Nomex" and others.) honeycombs used on this and other aircraft. Thus, the area of glued structures on the plane is approximately 250 m2. In this regard, the requirements for quality control of glued structures and, above all, for their reliability are increasing. The internal structure of the products is alternate layers of fiberglass with different winding angles impregnated with epoxy compound. With acoustic non-destructive testing, the heterogeneity of the structure and the instability of the technology cause the acoustic signal level to vary from product to product by up to 15dB. A large attenuation coefficient (up to 10-15 dB/cm at a frequency of 300 kHz in multilayer products made of fiberglass) forces the use of low-frequency piezoelectric transducers, and the complex and heterogeneous shape of the surface - the implementation of the automation process in a contactless version. The use of the echo method at low (up to 500 kHz) frequencies does not allow accurate measurement of the depth of the defect due to the spread of the speed of the ultrasound signal through the thickness of the product. This forces us to look for additional ways to increase the accuracy of determining the location of defects, which are delamination of the material between the winding layers. This work considers the possibility of using automated acoustic control of PCM products, which allows detecting defects on the basis without a reference setting of the signal threshold value, detecting and identifying defects by the depth of occurrence in the process of automated control, and evaluating the stability of the product manufacturing technology based on the control resultsThe article presents the modeling of an automated system of acoustic impedance non-destructive testing, which from a practical point of view will provide an opportunity to control the stability of the technological process of forming a composite material and, if necessary, make its adjustments. The advantages of creating a system of automated acoustic control will allow registration of scanning and control conditions in an expanded form of C-scan in the process of non-destructive control and improve the process of documentation of results and decision-making regarding product evaluation for normality or defect.

COMPUTER PROCESSING OF MEASUREMENTS IN PROBLEMS OF OBSERVATION OF THE CONDITION OF TECHNICAL OBJECTS

V. Malaichuk, S. Klymenko, D. Astakhov (Author) — Thu, 23 Feb 2023 12:57:04 +0200

Nonparametric statistics allow us to draw statistical conclusions, in particular, to evaluate the characteristics of the distribution and test statistical hypotheses, without, as a rule, poorly substantiated assumptions that the distribution function of the sample elements is part of a parametric family. For example, there is a widespread belief that statistics are often subject to normal distribution. Meanwhile, the analysis of specific results of observations, in particular, measurement errors, always leads to the same conclusion – in the vast majority of cases, the real distributions are significantly different from normal. In the tasks of non-destructive testing -non-parametric statistics are the basis for research and decision-making on the suitability or quality of products. Despite the large number of publications on specific issues of non-parametric statistics, the internal structure of this scientific field remains a pressing issue. Uncritical use of the normality hypothesis often leads to significant errors, for example, in the rejection of sharply observed results of observations (emissions), in statistical quality control and in other cases. Investigation of classical methods of nonparametric statistics in the problems of monitoring the condition of quality control objects on the basis of measured values. Methods. The most frequently used in practice criteria of nonparametric statistics, such as the Anderson and Smirnov criteria, are considered. And also in article their analogs for use in problems of reliability and quality control at the analysis of the measured sizes are resulted. The theoretical bases of statistical processing of experimental samples of independent random variables are considered in the article. A study of the scientific and technical problem of monitoring and control over the condition and quality of technical objects by comparing experimental samples of measurements in the processes of their development, testing and operation. New criteria for processingexperimental samples of independent random variables have been developed, the use of which, according to experimental results, has shown greater informativeness than the use of the already well-known Anderson and Smirnov criteria.

ACOUSTIC RADIATIONS OF A CYLINDRICAL FORM AT THE LAUNCH OF A ONE-NOZZLE ROCKET

E. O. Zagrevskyi, G. I. Sokol (Author) — Thu, 23 Feb 2023 12:56:32 +0200

When space rockets are launched, acoustic fields of various types of radiation appear in the atmosphere. Therefore, it is necessary to identify the features and determine the directions of research of acoustic radiation. The purpose of this work is to develop a methodology for studying cylindrical acoustic radiation at the launch of a one-nozzle rocket for space purposes in the first seconds of flight. At the same time, the following tasks are solved: development of physical models of acoustic fields; determination of types of acoustic sources; identification of sources of acoustic vibrations during rocket movement; calculation of sound pressure levels at specified points of the acoustic field. The calculation of the amplitude of acoustic pressure in the medium that surrounds a one-nozzle space rocket is performed. On the basis of the calculation results, the dependence of the lifting height of a one- nozzle space rocket on the flight time is constructed. In this paper, analytical methods based on those already known in acoustics will be used to compile a methodology for calculating the characteristics of acoustic fields, since methods for calculating the amplitude-frequency characteristics of acoustic radiation during rocket launches are not developed for all cases. The task of creating a methodology for calculating acoustic characteristics at the launch of a one-nozzle rocket for space purposes in the first seconds of flight is solved in a linear formulation. A simplified engineering methodology based on equations from acoustic sources and fields has been developed. The technique is used to calculate sound pressure levels in the far acoustic field, when the jet from the nozzle can be approximated by a cylindrical type emitter. It is found that the sound pressure level in the medium will not exceed the value of 144 dB. Based on the results of the physical and mathematical analysis of the sources of acoustic vibrations and their fields, which is shown in this work, at the stage of preliminary design and further development of the technique, it is possible to develop active and passive methods of damping acoustic vibrations.

HYDRO-GAS-DYNAMIC MODEL OF MOTION OF GAS-SATURATED LIQUID IN A CENTRIFUGAL POROUS PUMP

M. Katrenko, V. Eliseyev, А. Panchenko (Author) — Thu, 23 Feb 2023 12:56:02 +0200

An approach has been developed to the formation of a theoretical model of the movement of a gas- saturated liquid in the flow path of a porous centrifugal pump, as an assembly of the system for feeding the reaction mass of liquid-propellant rocket engines. The developed approach is based on a physical model of the turbulent motion of a gas-liquid mixture, within which conservation equations are used. Two models are proposed that describe the movement of a gas-liquid mixture in the flow path of a centrifugal porous pump in a two-phase one- dimensional formulation and a quasi-homogeneous one, complementing each other. A porous impeller of a closed- type centrifugal pump of constant width is considered. The energy losses of the gas-liquid mixture flow at the inlet to the pump impeller, as well as the losses of disk friction associated with rotation in a fixed housing, are not taken into account. The parameters of the viscous and inertial hydraulic resistance coefficients of the porous body are used. In particular, the influence of the static pressure gradient in a gas-saturated liquid and the friction force on the accumulation of gas at the inlet to the impeller and the stability of the liquid supply by the pumping unit is noted. The use of the developed approach makes it possible, by calculation methods, to evaluate the values of parameters characterizing the movement of gas-liquid media in centrifugal porous pumps of the designed systems for feeding propellant components to liquid-propellant rocket engines, to reduce the amount of experimental testing of new and modernized propulsion systems for space stages and launch vehicles.

THE METHOD OF OPTIMIZING THE OPERATING COSTS OF THE HEATING SYSTEM OF AUTONOMOUS BUILDINGS

V.L. Bucharskyi, V.G. Alekseenko, O.S. Cherniavskyi (Author) — Thu, 23 Feb 2023 12:55:24 +0200

This paper proposes a method of optimizing operating costs during the operation of the heating system of autonomous Earth sensing centers, command posts and other institutions that ensure the functioning of the rocket and space complex of Ukraine due to the optimization of mass consumption of coolant and solid fuel in the presented autonomous structure with a total area of 25 m2. Biofuel in the form of pellets is used as fuel. A heating system was designed for the selected building, for which a target function was defined to minimize operating costs. Expressions for thermal and hydraulic losses during the operation of the heating system were obtained. Heat losses of the building through the walls and ceiling are determined. Calculations of hydraulic losses of the heating system were also carried out. Mathematical models of elements of the heating system (solid fuel boiler and heating battery) were obtained. A mathematical model was built for finding patterns of changes in thermophysical parameters in the elements of our system. Models of radiators, solid fuel boilers and heat losses due to building enclosures are considered. The task of optimizing operating costs during the operation of the heating system was set and solved. The results indicate the possibility of significantly reducing heating costs due to the selection of the optimal mode of operation of the heating system. The obtained results can be used in the optimization of operating costs during the operation of the heating system not only when using biofuel as an energy source in the form of pellets, but also when using traditional types of fuel, such as natural gas and coal.

ANALYSIS OF THE CURRENT STATE OF EQUIPMENT DEVELOPMENT TO SEARCH FOR WATER ON THE MOON

І. Husarova, H. Osinovyi, T. Manko (Author) — Thu, 23 Feb 2023 12:54:26 +0200

Attention to the use of space resources, especially to the study of the surface of the Moon, is currently growing in the world. The main resource of the Moon that is of immediate value to humans is water. The location of large deposits of ice and in what form it is not yet known. Based on an analytical study of existing data, it is proven that solving the problem of extracting water and other potentially available resources on the Moon requires determining their location and nature. This requires the development of special technologies and modern equipment. Such equipment is currently being developed by NASA and ESA scientists. It is shown that the main tools for determining the location and form of existence of water on the Moon are a drill for sampling soil and ice and devices for determining their composition. The equipment on the Moon must work in conditions of space vacuum, space radiation, vacuum ultraviolet, large temperature changes. The conditions of the external environment that take place on the Moon have a negative effect on the devices and equipment used. Therefore, one of the main tasks in the design of equipment for the exploration and development of the Moon is to establish the performance, reliability and durability of the materials used. The effect of cosmic radiation on the properties of equipment materials is synergistic, so it is necessary to study the simultaneous effect of all active types of radiation. A complex simulator of space factors, created by domestic scientists, is presented, which allows you to study the simultaneous effects of vacuum, temperatures and various radiation flows. The complex simulator of space factors is a unique piece of equipment and enables Ukrainian specialists to participate in international programs on the development of the Moon.

CARGO SPACECRAFT FOR SUPPLY MOON INDUSTRIAL RESEARCH BASE

A. Pustovharov, H. Osinovyj (Author) — Thu, 23 Feb 2023 12:54:02 +0200

The exploration of the Moon, which is expected to begin in the near future, will be phased. Gradually, the permanent presence of people on its surface will be ensured. To do this, it will be necessary to create bases on the surface of the Moon, the projects of which are currently being worked on in different countries. One of the most important tasks will be to provide lunar bases with everything necessary, which can be done by sending from Earth automatic (unmanned) spacecraft with various cargoes. The means of delivery to the Moon of everything necessary will be considered further cargo spacecraft for supply. An analysis of the state of work on similar spacecraft in the world was carried out, the concept of using the cargo spacecraft for supply was worked out, in particular - the approximate nomenclature of cargoes was determined. The conceptual design of the spacecraft was also developed, its systems and equipment were described. Attention is paid to the principles of cargo placement inside. As a result of conceptual design, some characteristics were obtained and the appearance of the cargo spacecraft was formed. The means of delivery of the transport vehicle to the Moon are described, including a super-heavy space launcher, a lunar space tug and a lunar lander. Conceptual studies of the cargo spacecraft using modern design methods, including 3D modeling, showed that its characteristics are at the level of existing spacecraft used to supply the International Space Station, or promising ones that may be created in the near future. The work carried out allows us to conclude that the cargo spacecraft supplying the Moon industrial and research base is an important and promising means of studying and exploring the Moon. Creation and testing of the cargo spacecraft will make it possible to bring plans for the study and exploration of the Moon closer to reality.

APPLICATION OF THE LOITERING MUNITIONS TO DEFEAT AIR ENEMY TARGETS

O. Zhugan, D. Kalinichenko (Author) — Thu, 23 Feb 2023 12:53:06 +0200

Loitering munition is a new class of weapons that occupies an intermediate position between unmanned aerial vehicles and cruise missiles and combines the capabilities of reconnaissance and high-precision strikes. Appearing at the end of the 20th century, this class of weapons, along with reconnaissance and reconnaissance- strike unmanned aerial vehicles, plays an increasingly important role in modern military conflicts. To defeat loitering munitions and unmanned aerial vehicles, anti-aircraft artillery and anti-aircraft guided missiles are now usually used. However, it should be noticed that anti-aircraft artillery has a low probability of hitting an air targets, while anti-aircraft guided missiles have a significant cost and are limited in quantity. To ensure the interception of aircraft characterized by low speed and maneuverability, it is proposed to create an air defense complex based on loitering munition. Based on the research work carried out, it was established that the optimal organizational structure is a battery, which will include a command control vehicle, a surveillance radar station and up to six self- propelled launchers, on which a package of transport and launch containers with loitering ammunition is installed. The main targets of the complex are enemy medium range and long range unmanned aerial vehicles and loitering munitions, such as Shahed-136, etc. In addition, the complex is capable of being used against enemy helicopters. To solve the combat missions of intercepting the above targets, the basic requirements for the developed loitering munition were determined, including the speed and altitude of the flight, loitering time and the warhead mass. The calculations performed showed the possibility of creating a loitering munition with the appropriate characteristics, a layout diagram was developed and a 3D-model of the device was designed. Equipping the Armed Forces of Ukraine with an anti-aircraft complex based on loitering ammunition can significantly reduce the cost of intercepting low-speed targets and is proposed for the first time.

THIRTY YEARS IN ORBIT

Е.І. Kuznetsov (Author) — Tue, 21 Feb 2023 13:28:13 +0200

Article based on plenary report at the XXIV International Youth Scientific and Practical Conference "Human and Space", dedicated to the 30th anniversary of the State Space Agency of Ukraine (May 25-27, 2022). The 30-year history of the State Space Agency of Ukraine allows, despite all the troubles that were on the way of its formation and activity, to positively evaluate the integral and significant results of the agency's team and its significant contribution to the preservation of high-tech enterprises. In May 1993, the First Space Program of Ukraine was approved by the Resolution of the Cabinet of Ministers of Ukraine. It was necessary and timely for the development of the rocket and space industry the creation of the Institute of Space Research and the International Center for Space Law together with the National Academy of Sciences of Ukraine. After the formation of the rocket and space industry, a decision was made to grant NKAU the status of a specially authorized central division of the Government. Projects were implemented for the launch of the Sich-1 satellite, a joint Ukrainian-American scientific experiment on space biology, which was carried out in orbit by Leonid Kadeniuk, the first Ukrainian cosmonaut, unique international projects "Sea Launch", "Land Launch", "Dnipro", "EgyptSat". Access to the international market of space services was ensured. In July 2014, launch vehicle "Dnipro" launched 33 satellites at the same time on the order of 17 countries. For 30 years, 5 State scientific and technical Space Programs have been developed and implemented. Each of them was designed for five years. A modern, science-intensive high-tech rocket and space industry of Ukraine was formed, Agreements on cooperation in the space sphere were concluded with 28 countries, the National Center for Control and Testing of Space Technique, the Institute for Space Research (ICD) and the International Center for Space Law (ICPL), the National Center for Aerospace youth education were created; 29 space vehicles were launched, including "Sich-1" for the first time under the jurisdiction of Ukraine, new class "Sich-1M", "Sich-2", "Mikron", "EgyptSat-1", "Sich-2-1"; the space project "Dnipro" based on the RS-20 rocket was implemented; the domestic missile complex "Cyclone-4" was developed; 132 launchers of Ukrainian design were launched from 6 cosmodromes around the world, more than 380 satellites were launched into space, 29 of which were designed and manufactured by Ukraine.

DEVELOPMENT OF A PERSPECTIVE SYSTEM OF MAINTAINING OPTIMUM RANGE OF PRESSURE IN TANKS BASED ON THE APPLICATION OF THROTTLE REGULATORS WITH FEEDBACK

D. Lukin, V. Skochko, D. Mazhuha (Author) — Sat, 20 Nov 2021 00:00:00 +0200

Зниження маси баків ракет-носіїв істотно впливає на підвищення їх енергетики. Зниження ваги баків може бути досягнуто за рахунок зниження діючих на них навантажень. Зниження навантажень, як правило, забезпечується зниженням максимального тиску в них при мінімізації діапазону його зміни. В даний час підтримка тиску в баках РН, що працюють на кріогенних компонентах палива, здійснюється за допомогою жиклерної системи надуву, для якої різниця між мінімальним необхідним (1 ÷ 2 кгс/см²) і максимальним розрахунковим тиском в баку становить ~ 0,9 ÷ 1,0 кгс/см². Зазначена система не дозволяє домогтися більш вузького діапазону підтримуваного тиску в баку. Виникає необхідність створення системи підтримки бакового тиску (СПБТ), здатної плавно змінювати прохідний перетин виконавчого елемента в залежності від величини реєстрованого тиску в паливному баку. До складу системи підтримки бакових тисків повинні входити дросель-регулятор, привід управління дроселем і система управління приводом. На практиці є істотний досвід створення приводів управління і дроселів регуляторів. Для управління зазначеної кінематичної пари необхідне створення системи управління, здатної за показниками бакового тиску забезпечувати подачу керуючого живлення на електропривод. Проведені чисельні експерименти показують, що при створенні системи управління, що працює на простих алгоритмах, є можливість забезпечення стабільного діапазону тиску в баках, а можливі зниження максимальних їх значень складають не менше 0,8 кгс/см² в порівнянні з жиклерними системами наддуву. Підтвердження працездатності такої системи і визначення оптимального алгоритму управління можна провести при проведенні автономної відпрацювання кінематичної пари дросель-регулятора і приводу управління. При цьому не потрібно створення штатної системи управління, а для заміру фактичного ривня тиску в баку, можна використовувати сигналізатори, які використовуються в жиклерних системах надуву.

METHODS OF GRAPHIC CONSTRUCTION OF THE PROCESS OF MANUFACTURING THE POWER SHELL OF COMPOSITE FUEL TANKS

О. Litot, Т. Man’ko (Author) — Sat, 20 Nov 2021 00:00:00 +0200

The article is devoted to the problem of modeling the process of manufacturing a power cladding of composite fuel tanks obtained by the winding method. When studying the process of winding a fuel tank, much attention is paid to the formation of its bottoms. The formation of a massive pole thickening in the load-bearing shell, which is created during the pole rotation near the choke, creates not only excessive weight of the structure, but also creates significant axial forces. The gradual retraction of spiral layers and the creation of zoning can significantly relieve this part of the structure. In this case, the task is to correctly calculate and graphically display the obtained layered structures. The task becomes more complicated when studying the issue of winding the ends of a complex shape. To solve this problem, the process of graphical construction of the shaping of the power shell of a lineless composite fuel tank with a small pole hole is considered. The model is based on a mathematical representation of the forming mandrel function for the first layer, and iterating it for subsequent ones, taking subsequent surfaces as reference. To implement the model, 3D CAD systems are applicable, which allow working with functions and parameterization. High attention is paid to the problems of forming the winding surface of the layers of the power shell in the area of the pole hole, including for fuel tanks with bottoms of complex geometry. The effectiveness of the structural and technological decisions is confirmed by the nature of the destruction during the tests. The resulting model was confirmed during the manufacture of an experimental design.An assessment of the results obtained and conclusions on the work done are presented.

INFLUENCE OF WELDING PARAMETERS ON THE PERFORMANCE CHARACTERISTICS OF THE THERMOCATODES

A. Sanin, Е. Dzhour, І. Mamchur, S. Mamchur, Т. Nosova (Author) — Sat, 20 Nov 2021 00:00:00 +0200

The paper considers materials for the manufacture of a hot cathode based on lanthanum and niobium hexaboride. Lanthanum hexaboride has high emission properties; therefore, it is used in many fields of technology for the manufacture of cathodes for direct and indirect heating. Comparisons of the activation energies of the processes of interaction of metals with boron during diffusion welding in vacuum, and the assessment of the efficiency of diffusion protection of the interaction surface due to the use of an intermediate layer are carried out. Based on the data, titanium was selected as an intermediate layer. Analysis of the state diagram of lanthanum-boron made it possible to determine the optimal welding temperature. The selected welding temperature is 1473 K, which promotes the intensification of the diffusion process. The diffusion interaction of layered compositions of lanthanum hexaboride, a niobium substrate, and a titanium barrier layer has been studied. The influence of the welding parameters on the length of the phase layers and the quality of the hot cathode for low-thrust ion engines is investigated. It has been established that the relationship between the development of diffusion layers and the quality of the welded joint using microstructural methods of analysis does not give reliable results. The microhardness measurement provides an approximate estimate of the total width of the transition layer. Qualitative micro-X-ray spectral analysis made it possible to graphically determine the length of each phase layer on the concentration scanning curve. Thus, the methodology of using physical research methods made it possible to determine the reliability of the scientific substantiation of the developed technological process for manufacturing welded structures and to assess their performance under operating conditions. The general requirements for the material of the hot cathode are determined: metals must have simple state diagrams; the system of metals to be welded must have at least two heat-resistant intermetallics; the system should form significant areas of solid solutions. The mechanism of formation of a diffusion compound of lanthanum hexaboride with titanium due to boron diffusion into titanium, in order to avoid recrystallization grain growth in the titanium interlayer and the formation of titanium borides, which provide an increase in the thermal stability of the compound, has been established. The use of the above research scheme and assessment of the relationship between phase formation and the quality of welded joints based on lanthanum hexaboride makes it possible to effectively select the material of the intermediate layers and welding modes for obtaining cathode devices.

INTERACTION OF STRUCTURE AND PROPERTIES IN MODIFIED ALUMINUM ALLOYS

Sat, 20 Nov 2021 00:00:00 +0200

The effect of modification with dispersed compositions on the structure and mechanical properties of deformed aluminum alloys has been established. Aluminum alloys of the Al-Mg, Al-Mg-Sc systems have been investigated. A dispersed composition based on silicon carbide powder SiC with a particle size of 50 ... 100 nm was chosen as a modifier for the alloys under study. The dispersed modifier is obtained by plasma-chemical synthesis. The charge material was SiC powder with a dispersion of 50 μm. The mechanism of action of the dispersed modifier in the aluminum melt, which is the center of the primary crystallization of the melt, is proposed. The microstructure of the alloys was studied by the method of optical microscopy, and the phase composition was studied by the method of X-ray spectral energy dispersive analysis. The mechanical properties of the alloys before and after modification were carried out in accordance with GOST 1497-84. Industrial melting of AMg6, 1570, 1420 alloys was carried out. A technological process of melting was developed with an optimal amount of 0.2% modifier from the melt mass. The temperature-time parameters of the modification have been developed. The existence of complex intermetallic phases thia Al₃(Sc_x, Zr_x-1) in the modified state, which are effective solid solution hardeners, has been established. A significant increase in the mechanical properties of sheet alloys in a modified state is shown: ultimate strength - from 400 MPa to 470 MPa; yield point - from 280 MPa to 361 MPa; relative lengthening - from 13% to 15.4%. A significant decrease in the grain size in modified alloys by 1.5–2 times in comparison with unmodified ones has been established. A homogeneous microstructure with dispersed intermetallic phases located in the volume of grains was obtained. Fractographic analysis of the samples showed the presence of a brittle type of fracture in the initial state and ductile-brittle fracture of the samples in a modified state. The relationship of the grain structure of modified alloys with an increased complex of mechanical properties has been established. The results obtained made it possible to improve the technological process for the production of high-quality critical aluminum alloys.

MATHEMATICAL MODEL FOR CALCULATION OF ERRORS FOR ESTIMATING ANGULAR VELOCITY OF THE SPACECRAFT

I. Sidorov, А. Manoilenko (Author) — Sat, 20 Nov 2021 00:00:00 +0200

At present, there is an increased interest in the creation of platform-free inertial navigation systems (SINS), which constitute the information core of modern on-board orientation and navigation systems for spacecraft (SC). SINS can include magnetometers, astro sensors, angular rate sensors (ARS). The accuracy of determining the spacecraft orientation largely depends on the SINS composition. The presence of ARS in the SINS provides the best accuracy. In this regard, the tasks associated with filtering "noisy" data from the control system, estimating and calculating the estimation errors, and calibrating the SINS sensors are relevant. In this paper, a mathematical model is proposed for solving the problem of calculating the errors in estimating the angular velocities of the spacecraft taking into account the filtering of the "noisy" data of the ARS. The model includes: a discrete model of the object of observation - the ARS and the model of the measurement process, which takes into account such parameters of the ARS as the instability of the pulse price, the non-orthogonality of the sensitivity axes, the instability of the zero shift, and the random drift of the sensor. The optimal recurrent Kalman filter is used as a filtering algorithm for the ARS data on the components of the spacecraft angular velocity vector, which makes it possible to minimize the root-mean-square error in estimating the object's state vector and to isolate the useful signal against the background of random noise. Such a filter for discrete models of the object of observation and the measurement process allows for optimal estimation in real time of the spacecraft flight. The parameters of the ADIS-16350 type ARS, which is made using MEMS - technology, were taken as the initial data. The results of numerical modeling of the dynamic processes of filtering the ARS data and the estimation of the angular velocities of the spacecraft are presented.

EFFICIENT DESIGN OF THE FUEL CASE OF THE LV “VEGA” ORBITAL STAGE USING TOPOLOGY OPTIMIZATION

Vladyslav Ivanovich Shynkaruk, Volodymyr Ivanovich Lipovskyi (Author) — Wed, 17 Nov 2021 00:00:00 +0200

The development of new aircraft manufacturing technologies makes it possible to create improved designs. In the article, we have studied the design element of the fourth stage fuel compartment of the launch vehicle (LV) «Vega» — AVUM (Attitude Vernier Upper Module). This element is called a case. Its function is to connect four fuel tanks into a single fuel compartment. A new version of the design is proposed based on the analysis of load conditions of the previous research object. While designing the aircrafts there are opposite criteria which should be met. On the one hand, the design must be strong, rigid, stable and at the same time have the least weight. Additive technologies have fewer restrictions on the complexity of designed geometry than traditional ones. Modern methods of topological optimization make it possible to determine the direction of force flows in a structure. Based on this data, the optimal design is determined to take into account the requirements of working capacity and minimum weight. The combination of new technologies with topological optimization methods allows to design parts more efficiently. Currently, metal 3D printing technology is developing in the direction of reducing restrictions on produced parts dimensions. It is possible to manufacture fuel tanks up to 2400 mm in diameter using additive manufacturing technique. Therefore, the proposed design of the AVUM fuel compartment case does not change main tactical and technical characteristics of the stage. The ultimate load cases were taken according to requirements for the LV «Vega». The proposed design option is based on the previously developed solution of replacing the flat plate with a spherical bottom with holes for the tanks. The application of topological optimization is considered in this paper to create a design option with minimum mass. Topological optimization was carried out for all load cases and, based on the obtained results, a superposition of the retrieved solutions was performed. A rational design option was (modelled/generated) based on the analysis of the obtained results with consideration of the technological restrictions. The fulfilment of the strength conditions for the designed geometry was approved with verification static analysis. As a result of the topology optimization, the mass of the final design is 30% lower than for the original one.

REDUCTION OF THE TEMPERATURE AND FORCE IMPACT OF SUPERSONIC JETS OF A ROCKET ENGINE ON OBJECTS OF GROUND TECHNOLOGICAL EQUIPMENT

R. Mochonov, А. Sotnichenko, H. Ivanytskyi, М. Salo, О. Brizhak (Author) — Wed, 17 Nov 2021 00:00:00 +0200

To prevent surfaces flowing under direct impact of high-temperature gas jets, the majority of up-to-date launch complexes of integrated launch vehicles (ILV) apply water feed systems. Nowadays the only feasible way of theoretical research of interaction of propulsion systems supersonic jets with water jets from water feed system headers is numerical simulation. To investigate thermal and force load on surfaces under impact of supersonic jets from propulsion system we carried out numerical simulation of gas-dynamic process in gas duct during integrated launch vehicle takeoff. We investigated the two options, with and without water feed. We took the Antares ILV gas duct as a prototype. Our mathematical model is based on the two-phase medium dynamics equations. At this, the gas flow is described by the three-dimensional Navier-Stokes equations, and at simulation of water drops we applied Lagrange trajectory approach. The research was done in commercial code ANSYS Fluent. As a result of the numerical experiment we got data on efficiency of reduction of thermal and force impact of propulsion system supersonic jets on gas duct structure at use of water feed system. Based on the research we worked out the key recommendations that might be of use at design and optimization of water feed systems of ILV ground complexes.

REVIEW OF INTELLIGENT MATERIALS AND THE POSSIBILITY OF THEIR USE IN ROCKET AND SPACE TECHNOLOGY

Yevhenii Serhiyovych Petelko, Volodymyr Ivanovich Lipovskyi (Author) — Wed, 17 Nov 2021 00:00:00 +0200

A new generation of materials – «intellectual» materials – is rapidly developing. Intelligent materials are materials that react in a certain way to changes in the state of the environment or the influence of force fields, vibrations or oscillations and radiation. This reaction results in the alterations of material properties, geometry and its adaptation to changes in operating conditions. Constructions are made of intelligent materials, in addition to the traditional functions of taking operational loads and ensuring load and strength, can provide self-monitoring, identification and localization of the fatigue damage. The material in such constructions can contain a set of electronics, built into the structure, which performs the function of receiving, processing and transmitting information in different frequency ranges. Intellectual material requirements are defined by the purpose and conditions of use of the structures and their components. The objective of this work is to give an overview of intellectual materials, in order to introduce the main information about their properties and their applicability in space and rocket technology. Furthermore, in this article data processing and analysis were carried out, which allowed to formalize the properties of the considered intellectual materials. Moreover, the application of intellectual materials can improve existing design schemes and elements or create entirely new design solutions in the future. For instance, the use of magnetostrictive materials allows to reduce the longitudinal oscillations of the launch vehicle on an active part of the trajectory along with absorbing vibrations and regulating the stringency of the stage separation. Structural analysis of the special properties of intellectual materials and their application not only will solve existing problems, but also enable further development of the space rocket industry.

PHENOMENON OF THE LOCAL CLOSE-RANGE PEAK OF MINIMUM REQUIRED LAUNCH MASS IN TACTICAL AND SURFACE-TO-AIR MISSILES DESIGN

A. Chubarov (Author) — Wed, 17 Nov 2021 00:00:00 +0200

The aim of this article is to highlight the phenomenon of the local close-range peak of the minimum required launch mass of tactical and surface to air guided missiles. This phenomenon was identified by the author during the study of the areas of optimal design solutions (design parameters) for these classes of missiles. This phenomenon occurs during the design of missiles of these classes of minimum mass in the presence of constrains on the minimum allowable terminal velocity at zero or extremely low altitudes. The essence of this phenomenon is that the dependence of the minimum launch mass on the range at given constraints is not monotonic and contains a local maximum at some close range and a local minimum at some "middle" range. The research was carried out by two-criterion optimization of design parameters of the specified classes of missiles with simultaneous optimization of flight trajectories using genetic algorithm. In the considered basic calculation case, the minimum required (peak) launch mass when shooting at a range of 25 km is similar to the minimum required mass when shooting at a range of 80 km. Failure to take into account this feature of the dependence of the minimum required launch mass on the flight range can lead to the fact that the distances in the location of the peak will be unattainable for the missile with the minimum required terminal velocity. To analyze the causes of this phenomenon, the calculated case of a tactical missile flying at different distances on optimal trajectories with maximum terminal velocity was additionally considered. The obtained results allowed to determine the causes of the phenomenon of local close-range peak of the minimum required launch mass. This phenomenon must be taken into account when designing missiles of the considered classes to ensure the reach of the entire span of range with the specified constrains.

CYCLOGRAMS OF THE ST-25 HALL THRUSTER STARTING

Oleksandr Alekseenko, Kashaba Andrey, Viktor Maslov, Olexandr Petrenko (Author) — Wed, 17 Nov 2021 00:00:00 +0200

The results of the start sequence diagram selection and experimental tests of the ST-25 Hall thruster intended for using on small spacecraft are presented. In order to reduce the mass and dimensions of the power processing unit of the propulsion system, it is proposed to exclude the hollow cathode keeper power supply from the structure of the power processing unit. The exclusion of the keeper power supply from the power processing unit made it necessary to select the thruster start sequence diagram. Four start sequence diagrams of the ST-25 Hall thruster start-up are considered: a) using a separate high voltage power supply for the hollow cathode keeper; b) using a separate low voltage power supply for the hollow cathode keeper; c) using a discharge power supply connected to the keeper through a high-resistance resistor to the hollow cathode keeper; d) connecting the keeper of the hollow cathode to the discharge power supply through an electronic switch with the possibility of adjusting the duration of the keeper connection to the discharge power supply. The graphs of changes in the thruster’s currents and voltages for various power supply circuits of the hollow cathode keeper are presented. The results of the choice of the start sequence diagram for the Hall engine ST-25 and the experimental studies carried out have shown that the use of an electronic switch with a steep pulse front makes it possible to obtain a reliable thruster start-up when a separate power supply for the keeper is excluded from the power processing unit of the propulsion system. As a result of the work carried out, it became possible to place the power processing unit for a propulsion system based on the ST-25 thruster in a volume of 2U. The possibility of using ST-25 thruster on spacecraft, the onboard electrical power of which is limited up to 200 W were confirmed.

CURRENT STATE AND PROSPECTS FOR DEVELOPMENT OF ENERGY PERFECTION OF VANE PUMPS

G. Nazarenko, P. Filipenko, S. Deshevykh, U. Mitikov (Author) — Wed, 17 Nov 2021 00:00:00 +0200

Оne of the most important problems of the XXI century is the problem of energy saving. It covers all spheres of human activity. The use of energy saving of pumping equipment is also very relevant. Pumps of various types and different designs are widely used in general engineering, military and aerospace industries. Ensuring high energy characteristics of pumps is one of the most important parts of energy saving problems. The results of the research showed that it is very important to improve energy performance. Works are carried out in all branches of industry and for all types of pumps. Improvement of energy properties is performed in the following direction: Development of new mathematical models describing in more detail the physicss of the working process for each specific type of pump; use of ANSYS software. But in modern literature there is no information about the increase in energy characteristics of low fluid flow low-speed inducer-centrifugal pump liquid propellant rocket engine. Therefore, such research is very important and their results will be in demand in the scientific community. There is no comprehensive approach to identifying ways to increase energy characteristics for low fluid flow low-speed inducer-centrifugal pump liquid propellant rocket engine. In turn, the high energy characteristics of the units of the fuel and oxide supply system units high energy characteristics of the upper stages of the launch vehicle, And the weight of the payload which deduces launch vehicle largely depends on them. It is necessary to conduct a comprehensive experimental-theoretical study during which methodological tools will be developed that allow in a short time and with high accuracy to increase the energy characteristics of low fluid flow low-speed inducer-centrifugal pumps liquid propellant rocket engine upper stages launch vehicle.

TEST RESULTS OF A HIGH-SPEED SOLENOID VALVE FOR THE ELECTRIC PROPULSION FEED SYSTEM

Bohdan Yurkov, Oleksandr Petrenko, Dmytro Voronovskyi, Troyan Andrey (Author) — Wed, 17 Nov 2021 00:00:00 +0200

Today in the world there are many electric propulsion systems based on the different types of thrusters. Most of them used gaseous propellent. Typical Electric propulsion system (EPS) consists of following main subsystems: the electric propulsion thruster that creates thrust; the power-processing and control unit which provides energy to all subsystems; the storage and feed system that performs functions of storing working substance in the tank and supplying the required amount of working substance to the thruster; Solenoid valve is a part of storage and feed systems. The feed system is an essential part of any electric propulsion system. The life cycle of the feed system is largely determined by lifetime of the valves and the amount of working substance in tank. Whereas the amount of working substance is selected based on the requirements for each specific mission valve parameters must be satisfying for various missions. Accordingly, the valves must have low power consumption, high reliability with a long lifetime (more than 10⁶ cycles), low weight and dimensions. Solenoid valve is an electromechanical device that consists of moving part controlled by an electromagnet. Movement of the movable element and the seal are key parts of valve reliability. Presented solenoid valve design uses two membranes, which perform the function of centering the moving element and with the spring provide the required closing speed and the seal of the valve. The paper presents the problem of selecting critical elements that affect the solenoid valve's performance, procedure and test results required for the qualification of space equipment. Manufactured valve was successfully tested (vibration testing, response time testing with inlet pressure change, response time testing at different operating voltages, dependence of the valve actuation current on the operating voltage, temperature testing, lifetime tests) separately and as part of XFS according to the ECSS standards. As well as the successful implementation of presented valve into the flight xenon feed system for electric propulsion.

GENERAL CASE OF LIQUID MOTION IN A POROUS RADIAL CENTRIFUGAL PUMP

Wed, 17 Nov 2021 00:00:00 +0200

Prospects and increasing use of porous structures in the design of fuel supply units for aircraft engines determines the importance, relevance and necessity of theoretical research aimed at creating a mathematical model of the motion of viscous, incompressible fluid in rotating porous bodies. A system of equations of motion describing the movement of a fluid in a porous wheel in a polar coordinate system is considered. Due to the great difficulties of analytical determination of the mass force of resistance in the model, it is assumed that it consists of the force of frictional resistance and the force of pressure resistance. A system of equations describing the motion of a fluid in a porous wheel is written in the polar coordinate system under the assumption that the change in the parameters of the fluid along the angle of rotation does not occur. In the laminar mode of motion, the filtration characteristics are expressed in the form of symmetric tensors of the second rank. The mass force of frictional resistance in the case of a turbulent mode of motion takes into account the accepted law of resistance. The action of the pressure gradient from the centrifugal forces during the motion of the fluid in the rotating porous wheel and the anisotropic properties of the porous element are taken as obtained during the motion of the fluid in a stationary sample. Therefore, from previous experimental studies, only the mass force of frictional resistance is taken into account, and the force of pressure resistance is taken into account in the equations. The equation connecting the static pressure of the fluid with the angular velocity of rotation and the geometrical parameters of the porous impeller and the gap is obtained.

APPLICATION OF INFRARED RAYS DURING MANUFACTURING OF CELECTIVE BANDAGING FOR OIL INDUSTRY FROM POLYMERIC COMPOSITION MATERIALS

K. Siedachova, T. Manko, O. Romenska (Author) — Wed, 17 Nov 2021 00:00:00 +0200

Paper is focused on current oil industry of Ukraine, which almost every day faces with problem of corrosion destruction of transportation system. With a total capacity of initial processing of 51-54 million tonnes of oil per year, the pipelines are corroded for 3-4 years during the maintenance-free service life. Lately, much attention is given to developments, related to anticorrosion protection methods of oil-and-gas pipelines, run in soil with different level of mineralization, in swamp, uliginous soils, containing sulfate-reducing bacteria, using development of mix of new composition of corrosion-resistant coating. Traditionally, the ground, atmospheric and other types of corrosion protection provide with effective selection of insulation coating in combination with cathodic protection (e.g. rolled plastic covering). However, the results of these developments have a variety of disadvantages, since the adhesion and corrosion-resistant characteristics as well as complicate technology of using and high price of materials are uncovered. The work offers energy-efficient technology for repairing oil pipelines with a diameter of 146 mm using, bandages made of glassplastic on the basis of fiberglass RT 800 and epoxy connector using selective infrared radiation. Bandage was applied on the model of pipeline with hand lay-up. To reduce for pipeline repairs it is proposed to use device with infrared rays during polymerization bandage. The source of infrared radiation is halogen lamps, inertia of which is six seconds. During testing with internal pressure, pipeline with bandage lost impermeability at value of internal pressure, which is equal about 7.6-8.0 MPa. This is 5 times higher than operational pressure of pipeline with diameter of 146 mm which is equal 1.5 MPa.

OVERVIEW OF THE TYPE OF CLEANING FLUIDS USED TO CLEAN THE FUEL TANKS OF LAUNCH VEHICLES

О.В. Кулик, П.Н. Желтов, Д.С. Абраменко (Author) — Wed, 17 Nov 2021 00:00:00 +0200

The article provides an analysis of various types of washing liquids for removing organic and inorganic contaminants from the inner surface of domestically produced fuel carrier rockets. The characteristics of the removed contaminants from fuel tanks are described. The advantages and disadvantages of the most effective fluorinated washing liquids are described, the properties of freon-113 are described in detail. In connection with the decisions made at PA YuzhMash, a number of cleaning and degreasing technological processes were revised in order to exclude Freon 113 from the technological cycle. For the bulk of DAT, the degreasing technology was changed: the dipping method was replaced by the flooding method, degreasing in the vapor-gas phase of hladon-113 at the UOF-2 unit was excluded, the operational consumption rates were revised in order to reduce them, the equipment used was revised. In addition, gasoline and water-based detergents began to be used as technological materials instead of hladon-113. The necessity of using surfactant-based washing liquids has been substantiated. The applicability of cleaning liquids has been determined depending on the design features of the surfaces to be cleaned. Requirements have been made for alternative cleaning fluids. Multicomponent hydrocarbon solvents are obtained mainly on the basis of gasoline and kerosene fractions, as well as special petroleum solvents, which are obtained by strict selection of group hydrocarbon and fractional compositions - nefras, solvents and other hydrocarbon solvents for special purposes (Petrov's contact, cresols, etc.). On the basis of the regulatory framework of the industry and international standards presented in the article, an analysis of the possibility of using existing solvents instead of hladon-113 is carried out. Recommendations for the use of types of washing liquids from the types of in-tank elements are also given.

TOPOLOGY OPTIMIZATION FEATURES OF LIQUID-PROPELLANT ROCKET ENGINE POWER ELEMENTS MANUFACTURED BY ADDITIVE TECHNOLOGIES

O. Bondarenko, S. Vekilov, Y. Tkachov, R. Marchan (Author) — Wed, 17 Nov 2021 00:00:00 +0200

Today, rocket and space technologies are reaching a new level. The development of additive technologies and the use of new materials for 3D printing have a positive impact on the industry as a whole. Competition is growing rapidly in today's space rocket market, so the vast majority of space companies (public and private), such as RocketLab, SpaceX, Firefly Aerospace, FlightControl Propulsion, BlueOrigin and others, are increasingly using 3D printed products and parts. 3D printing significantly speeds up the production time of certain products, which is extremely necessary for large series production. Also, with the development of additive technologies, greater opportunities have opened up for the creation of atypical geometric shapes of certain parts. Additive technologies have several manufacturing methods (one such method is SLM (Selective Laser Melting), which was used to make an optimized bracket). The paper presents the principle of topological optimization, on the example of one bracket. The scheme of the algorithm when performing topological optimization is given. The process of topological optimization is described, i.e., the full cycle is shown. The main principle of the SIMP method is given. Based on the obtained intermediate result, the strength analysis (using the finite element method (FEM)) of the bracket before and after topological optimization for different design cases (axial compressive load, quasi-static overload load) was performed, where the final design variant was determined. This design has passed a number of static tests (in real operation) and has proven itself in the work on the product, where the intended purpose.

DISTINCTIVE FEATURES OF SLM TECHNOLOGY APPLICATION FOR MANUFACTURING OF LPRE COMPONENTS

Wed, 17 Nov 2021 00:00:00 +0200

In view of the growing competition in the modern market for rocket and space technology products, the issue of maximizing the cost reduction of the process of its production is urgent. In particular, the rocket engine is traditionally one of the costliest and technologically demanding rocket units, which basically reduces the problem of reducing the cost of rocket production to the development of new, more technologically advanced and less costly, approaches to manufacturing LPRE components. Thus, it is of increased interest to use a relatively young method for producing parts by layer-by-layer melting of thin layers of metal powder by exposing it to high-power laser radiation. This method is a part of the methods of additive technologies and is called SLM (Selective Laser Melting). In order to assess the influence of the main features of the production of components, the study of hydraulic channels manufactured with the additive SLM technology was carried out, and a load-bearing element of the fastening structure was manufactured which geometry was obtained by applying topological optimization methods. The aim of the work is to determine the main hydraulic characteristics of inner channels of typical LPRE’s elements, as well as the limits of the technology applicability in terms of liquid-propellant rocket engines. The possibility of manufacturing elements, including hydraulic paths, was investigated: regeneratively cooled cylinders, throat inserts of a liquid-propellant engine, as well as experimental designs of film cooling rings were adapted to be produced by means of SLM. The possibility of producing thrust frame, the shape of which was obtained by the method of topological optimization, was investigated. Samples of designs of typical hydraulic channels, as well as the constituent elements of the design of the rocket engine chambers, were manufactured. The main hydraulic characteristics of the typical hydraulic channels, as well as the distinctive features of their production using the method of additive technologies SLM, were determined. The thrust frame, which geometry was obtained by means of topology optimization, was successfully manufactured.

WAYS TO INCREASE PLASTICITY IN DEFORMATION OF TITANIUM ALLOYS WITH MINIMIZATION OF ENERGY COSTS

Serhii Polishko (Author) — Wed, 17 Nov 2021 00:00:00 +0200

This article dial with study, which was carried out to increase the ductility and deformability of titanium alloys BT1-0 and BT6, as well as the formation of highly plastic β-phase emissions in the microvolumes of the alloy. It was determined that the reason for the satisfactory combination of high plastic and impact characteristics with significant strength (σ_в> 800 MPa) were the following factors: the formation of a significant amount of metastable β-phase, has high plasticity and favorable morphology of the structure in the form of quasi-eutectoid, in which α -phase alternates with plastic β-layers. Research and experiments based on the new concept have proven the prospects of microalloying titanium with a non-deficient effective alloying element, iron. It also shows the real possibility of using much cheaper low-grade sponge-titanium (compared to high-purity sponge titanium) in the smelting of ingots and their processing with a decrease in energy consumption of processing processes and significant economy of titanium. Analysis of these experimental data allowed us to draw the following conclusions. With an increase in the amount of iron in the alloys of the Ti-Fe system, the yield strength and Brinell hardness naturally increased. As shown, iron "loosens" the crystal lattice of titanium and can’t increase the strength of the interatomic bond. Therefore, the nature of the strengthening of titanium iron is different. It is due to the following: grinding of grain in cast and forged states under the influence of iron. It was found that the size of cast grains decreased tenfold during doping titanium alloys by iron. Thus, with increasing concentration of iron in the titanium alloys, the length of the grain boundaries, which were an obstacle to the movement of dislocations, increased sharply.

ANALYSIS OF THE POSSIBILITY AND PROSPECTS OF USING THE BLASTING METHOD FOR CLEANING THE CLOSED BLADES OF TURBINE MONO WHEELS MANUFACTURED BY THE ADDITIVE METHOD OF THE SLM TECHNOLOGY

Yu. Shashko, S. Adjamskіy, S. Kazeev, А. Sanin, О. Kulyk (Author) — Wed, 17 Nov 2021 00:00:00 +0200

The introduction of three-dimensional printing is an important stage in the development of the rocket and space industry. Additive production is considered as an alternative to traditional processing methods such as milling, stamping and casting. The results of this work were obtained experimentally and can be used in the development of real technological processes in the enterprise. Additive technologies allow to simplify and speed up the manufacturing process, but the problem of ensuring the required quality and roughness of the treated surface of the blades remains relevant. The reason for this is the difficult, and in some cases impossible, access to traditional cutting tools, such as end or spherical cutters. This article presents the results of scientific-analytical and experimental work, the main task of which was to assess the possibilities and prospects of using existing methods of finishing closed-type monocycles made by 3D-printing using SLM technology (Selective Laser Melting).The question of the possibility of using the blasting method to obtain the required surface quality and shape of the working profile of the blades was addressed. The object of the study is the surface treatment of the impeller of a closed type turbine (with a bandage). This type of construction is the most rational in terms of structural strength, manufacturability of gas-dynamic characteristics and has a higher level of efficiency compared to open-type turbines. This work is an urgent task for finding promising and alternative methods of surface treatment of closed turbine blades obtained by the additive method.

CONTROL UNIT OF TEST BENCH FOR ELECTROMAGNETIC ORIENTATION AND STABILIZATION OF SPACECRAFT

E. Skidan, А. Kulabukhov (Author) — Wed, 17 Nov 2021 00:00:00 +0200

The control unit and methodical support of the test bench are offered. The task of the stand is to simulate the change of the Earth's magnetic field during the movement of the spacecraft in orbit to test the algorithms of the angular orientation system and stabilize the spacecraft. The article presents a model of the Earth's magnetic field, as well as the matrix of the transition to the oscillating coordinate system. The article describes the calculation of control currents to maintain the required number of ampere-turns, the control algorithm includes 2 PID controllers, and describes the block diagram of the control unit. The control unit has overcurrent and voltage protection, as well as short-circuit protection. To increase the accuracy of maintaining the desired magnetic field strength, an algorithm is implemented that uses current sensors and a three-axis magnetometer, which is installed in the center of the Helmholtz ring system. For management the standard USB interface, for connection to the personal computer is implemented. The output stages of the control unit are implemented according to the H-bridge scheme. The control unit has six independent control channels that have the same technical characteristics. The software interface numerically and graphically shows the magnitude of the magnetic field along three axes. The interface also shows the amount of current in the coils and the correction factors of the PID controller, as well as the input values of the field strength of the model of the Earth's magnetic field, which can be downloaded into the program by clicking "download model". The software allows you to control the control unit in manual and automatic mode, using the model of the Earth's magnetic field, thereby simulating the magnetic field given the nature of the spacecraft, which allows you to more accurately determine the characteristics of angular orientation and stabilization.

EFFICIENCY OF INNOVATIVE ROCKET - CARRIER STAGE CONTROL

Y. Sheptun (Author) — Wed, 17 Nov 2021 00:00:00 +0200

Any actual movement of the stages of spacecraft carrier rockets is a disturbed movement. An important purpose of missile stage control systems is to ensure that the perturbed values of the parameters of the motion of the stages approach the permissible values. Providing this requires energy (fuel from the rocket tanks). The quality of the missile control process is characterized by a significant number of indicators, including the amount of energy (fuel) spent on testing, within the limits of the necessary, perturbations of the motion parameters. Until now, the algorithms for determining the specified amount of energy in relation to the first and space stages of rockets practically do not differ. The advances in the development of technology, theory and practice of creating rocket and space systems, modern control systems using digital computers with elements of artificial intelligence, will make it possible to improve the models of rocket and space technology in the important direction of minimizing the overhead consumption of fuel from the rocket tanks. The proposed work presents the results of theoretical studies of the problems of automatic regulation of the values of the parameters of the disturbed movement of the space stage of the launch vehicle by the control system with the implementation of the inventions "Method for controlling the stage of the launch vehicle", "Method for controlling the stage of the launch vehicle with asymmetry", protected by the corresponding patents of Ukraine. The positive effects due to the application of these innovations are substantiated. The above inventions are based on the results of the analysis of the peculiarities of the perturbed motion of the space stages of launch vehicles, taking into account the latest achievements of rocket and space science and technology: the space stages of launch vehicles move outside the dense layers of the atmosphere, the perturbations of the parameters of the movement of the stages are characterized as such that they are constantly updated and such that are repeatedly instantaneously formed during the flight time of the degree. Constantly updated perturbations are caused by the mass asymmetry of the degree, the value of which can now be automatically controlled by a modern digital drive; Instantly generated perturbations are caused by repeated programmed space maneuvers of the Cosmin rocket stages. These disturbances with the required quality are measured by modern measuring instruments, which opens up the possibility of optimal energy consumption for working out these disturbances. The paper substantiates the positive effects aimed at minimizing energy consumption from the use of the above-mentioned innovative ways of controlling the rocket stages. The given quantitative estimates of the indicated effects, determined with respect to the rocket, close in parameters to the carrier rocket of the light class "Cyclone-4" developed by the State Design Bureau "Yuzhnoye".

METHODOLOGY OF SELECTING FLYWHEELS FOR STEREO IMAGING SURVEY

Е. Grebenkina, V. Larin, А. Kulabukhov (Author) — Wed, 17 Nov 2021 00:00:00 +0200

The problem of dynamic parameters of earth observation satellite angular motion is described. The process of Earth surface objects stereo imaging per 1 orbital period and flywheels requirements for it is considered. Stereo imaging process can be performed in two cases. In the first one - during several orbital periods, but with the significantly reduced efficiency of the received information. In the second case - the stereo imaging process can be carried out in one orbital period. In the second case, within one orbital period and small reasonable attitude angles, there is no information about determination of the time of spacecraft reorientation depending on its orbit in the existing methodologies. Let suppose that when a spacecraft is approaching the target of imaging (earth surface object) it is oriented relative to the nadir at an angle β and the corresponding angular velocity. This angular velocity ensures spacecraft orbital movement with a given deviation angle from nadir, thus the spacecraft is preliminary oriented for the first survey. Usually, the angle β is chosen in the range of 10-15⁰. It could be increased due to changing distance to survey target but the difficulties of information processing and scaling appear. The methodology of selecting flywheels on project stages is developed. This methodology takes into account the spacecraft characteristics, orbit height and acceptable survey angles. It allows the stereo imaging survey in one orbital period. The dependencies of flywheel control torque, spacecraft characteristics and stereo imaging survey attitude angles are established. The recommendations of selecting flywheels for stereo imaging survey in one orbital period are developed. Simulation of spacecraft attitude control process in stereo imaging survey was carried out. According to this simulation the changes in requirements to flywheels for different spacecrafts, orbits and acceptable survey angles were estimated.

LAW OF CONTROL AND INDICATORS OF THE MISSILE STABILIZING SYSTEM

V. Avdieiev (Author) — Wed, 17 Nov 2021 00:00:00 +0200

The main indicators of the rocket stabilization system include the margin of safety and accuracy, as well as the requirement for the power of the executive device. The margin of stability can be quantified as the distance of the operating point in the space of the coefficients of the law of control to the boundary of the region of stability and as a margin for the amplitude and phase of the frequency response. In this work, it is defined on the plane of the roots of a characteristic polynomial as the distance from the imaginary axis of the complex plane to the nearest root. To estimate the accuracy of stabilization, the reduced static error of the yaw angle is chosen. Power requirements for the actuator are defined as the operation of the equivalent steering in the transient process of constant disturbance compensation. In a competitive environment, there is a need to improve the methodology for establishing the dependence of these indicators on the parameters of the missile and the law of control. The object of the study is the system of stabilization of the plane rotational motion of the rocket, the subject of the study is the accuracy, margin of safety and the work of the executive device on the transient process of disturbance compensation depending on the control circuit parameters. The aim is to develop an algorithm for establishing the dependence of these indicators on the presence in the law of regulation of terms proportional to the angle and angular velocity of the equivalent steering gear. A linear stationary model of the plane rotational motion of a rocket in the vicinity of a certain point of the trajectory with taking into account the inertia of the executive device is adopted. For the case when only two of the four coordinates of the state vector are taken into account in the law of control, the restriction from above of the stability margin from the parameters of the actuator and the range of roots of the characteristic polynomial on a straight, parallel imaginary axis of the complex plane are set. For the variant in which all coordinates of the state vector are taken into account in the law of control, the algorithm of optimization of a margin of stability and a static error of stabilization is developed. The estimation of the power requirement of the executive device is obtained using the model of the equivalent steering body in the form of an oscillating link, the parameters of which are stiffness, damping coefficient and moment of inertia. It is shown that the stabilization error and the power requirement of the executive device without changing the stability margin depend on the location of two given roots on the straight, parallel imaginary axis of the complex plane. By simulation it is established that taking into account in the law of control of an angle and angular speed of an equivalent steering gear of the executive device can give improvement of the chosen indicators of system by 10 - 20%. The materials of the work supplement the methodological basis of the missile stabilization system design.

DETERMINING THE INFLUENCE OF ICING ON THE AIRCRAFT

S. Alekseyenko (Author) — Wed, 17 Nov 2021 00:00:00 +0200

In certain flight conditions, supercooled water droplets contained in clouds can freeze, falling on the aerodynamic surfaces of the aircraft. The resulting ice build-up can have a significant effect on the aerodynamics of the aircraft, changing the shape of the surface itself and its roughness. However, the question of determining the degree of this negative effect of icing on the aircraft, which has a certain layout, configuration and dimensions under given meteorological and flight conditions, is rather complicated and still far from complete. The paper proposes and illustrates a methodology for determining the degree of the negative impact of icing on the aircraft, which is following the regulatory documentation and the existing system for determining icing conditions, and allows taking into account both the configuration and dimensions of the aircraft, as well as meteorological and flight conditions. The technique is based on the developed software and methodological support, which allows to numerically simulate the processes of icing of aerodynamic surfaces of the aircraft. When describing the air-droplet flow and moisture deposition on a streamlined surface, the model of interpenetrating media was used, and when describing the process of ice growth, a technique based on the equations of continuity and conservation of energy was used. Concerning the example of the NACA 0012 airfoil, systematic studies of the effect of icing on an aircraft were carried out in a wide range of flight and meteorological parameters; the calculation results in the form of four-parameter nomograms are presented. The given systematization of the results will make it possible to quickly analyze the icing hazard along the planned flight route in known meteorological conditions, as well as during the flight using current meteorological data, to develop recommendations for changing the flight plan. The technique can be supplemented with a detailed account of the effect of icing on the aerodynamic characteristics, stability and controllability of the aircraft.

ESTIMATION OF THE POSSIBILITY OF USING A SOLAR SAIL IN THE PROBLEMS OF COMBINED DEORBITING FROM LOW-EARTH ORBITS

V. Korobka, M. Dron, А. Golubek (Author) — Wed, 17 Nov 2021 00:00:00 +0200

To clean the upper segment of low-Earth orbits with an altitude of 1400-2000 km, the possibility of using a combined method of deorbiting to the Earth's atmosphere has been evaluated. It is based on the combined use of a jet propulsion system and a solar sail. A scheme has been developed for the combined deorbiting of a satellite with a lifetime of up to 25 years. Its features: the solar sail provides a gradual decrease in flight altitude, and the ignition of a jet propulsion system at the end of the deorbiting period - the formation of an orbit with perigee in the dense layers of the Earth's atmosphere (120 km and below). Simulation of the deorbiting processes of a large-sized satellite using a jet propulsion system, a solar sail and their combination has been carried out. A comparative analysis of the mass of the deorbiting system for various methods is carried out. At the same time, it is believed that the satellite is equipped with a jet propulsion system for additional orbital expansion and maintenance. For the deorbiting of a spacecraft with a mass of 1 ton from an orbit of 2000 km, the following results were obtained. The minimum solar sail area is about 1200 m². For comparison, the most expensive is the deorbiting by the active method using a jet propulsion system. It requires about 140 kg of propellant on board. The least costly steer is the passive method using a solar sail. It requires a system with a mass of about 34 kg on board. In turn, the area of the combined method lies between these two methods. It is inferior in mass to the passive deorbit system, but outperforms the active one. Its effectiveness in comparison with the active method ranges up to 76%. It can be used in cases where there are restrictions on passive deorbiting, for example, in terms of the overall and mass characteristics of the deorbit system or in terms of the control system lifetime.

OPTIMIZATION OF TRAJECTORIES OF MOTION OF INTELLIGENT MOBILE ROBOTS WITH REMOTE SENSING OF LANDS OF THE FOREST FUND

A. Zakora, V. Sazonov (Author) — Wed, 17 Nov 2021 00:00:00 +0200

The work is devoted to the choice of optimal trajectories of movement of intelligent mobile robots (IMR) with an autonomous system of movement and navigation during remote sensing of forest lands. This task is relevant when using mobile robots with limited operating time. It has many practical applications, in particular, in monitoring, photography, mapping, security patrolling of the forest fund, as well as in organizing the work of automated storage facilities. The considered problem is optimization; the target function is the sum of displacements of objects (WRI) to the locations of the task. To solve the problem, the transformation of the displacement matrix is used, which allows, as a result, to obtain the distribution of objects by target points with the least total displacement and in the format necessary for further use. To solve the problem, an algorithm has been developed with a preliminary division into subsystems. On the basis of the mathematical model of the IMR movement, the trajectories of movement are calculated for the optimal distribution of objects at work places. Analysis of the obtained results of mathematical modeling of the process shows a significant saving in time when moving objects to the place and, accordingly, an increase in operating time. The developed algorithm and software module provide an opportunity to optimize the distribution of intelligent mobile robots that record forest resources, as a result, to obtain objective information about the state of forest funds. The program is intended for use in monitoring, photographing forests. The software block is implemented as a separate module for integration into a geographic information system.

WATER PURIFICATION IN SPACE CONDITIONS

Wed, 17 Nov 2021 00:00:00 +0200

The life support system of the International Space Station must include the provision of drinking water to the crew and the treatment and disposal of wastewater. The cost of water delivery to the ISS is very high, so it is necessary to improve the technological schemes of wastewater treatment in space in order to reuse water in a complete closed cycle. The studies were performed based on the analysis of Ukrainian and foreign scientific sources and reporting data on the specifics of water use at space stations and the treatment methods of the used waters (wastewaters). In addition to international experience, our own research was used to develop a technology for wastewater treatment in space. The authors of the article analyzed the operation of existing wastewater treatment facilities in space and made recommendations for their use at the ISS. The developed technology for the treatment of wastewater and drinking water in zero-gravity (space) is based on the use of various reactors. They can be made of various materials (metal, plastic, etc.); they do not contain non-standard equipment that requires factory manufacturing. Compactness, complete tightness and small dimensions of bio- and physicochemical reactors allow them to be installed within the ISS. The cleaning process is easy to manage and can be fully automated. Water problems are central to the whole world, including in space. The ISS should have a system for the wastewater treatment and their closed use, since the supply of new water to stations significantly increases the cost of space exploration. Quality water is the health and well-being of people in space. Since there is no gravity in space, centrifugal forces (centrifuges) must be used to separate suspended particles from water. A comprehensive review of the issues related to wastewater treatment in space, allows us to conclude that it is necessary to regenerate water at International space stations (ISS). Indeed, to ensure the life support of the astronauts, a colossal amount of water is required, and its delivery to the ISS from the Earth is expensive.

ELECTROMAGNETIC ORIENTATION AND STABILIZATION SYSTEMS OF SPACECRAFT TEST STAND

Е. Skidan, А. Kulabukhov (Author) — Fri, 12 Nov 2021 00:00:00 +0200

A test bench is proposed, consisting of three pairs of mutually perpendicular coils and a control unit with software. The task of the stand is to simulate the change in the Earth's magnetic field when the spacecraft moves in orbit in order to work out the algorithms for the operation of the angular orientation and stabilization system of the spacecraft. The system has six independent coils, which have different parameters due to the design features. The article describes the calculation of the number of turns and the choice of the diameter of the wire of the coils, the calculation of the current and supply voltage to maintain the required number of ampere-turns, the choice of the geometric configuration and the calculation of the geometric parameters of the coils, as well as the block diagram and description of the control unit. This system is capable of providing a field strength five times that of the Earth. The degree of inhomogeneity of the modulus of the field strength does not exceed 1% in a sphere with a radius of 150 mm, which corresponds to the calculated data. The control unit supports manual control of each pair of coils, changing the magnetic field strength, and also provides current and magnetic field stabilization using current sensors and a magnetometer suspended on a tripod. The control unit has overcurrent and overvoltage protection, as well as short circuit protection. The output stages of the control unit are implemented according to the H-bridge scheme. The software allows you to control the control unit in manual and automatic modes using the model of the Earth's magnetic field, thereby simulating the magnetic field, taking into account the nature of the spacecraft movement, which allows you to more accurately determine the characteristics of the angular orientation and stabilization system.

HEATER OF THE HOLLOW CATHODE WITH LaB6 FOR OPERATION WITH HALL THRUSTERS

Tue, 09 Nov 2021 00:00:00 +0200

The article presents the results of design, development and laboratory tests at Space Electric Thruster Systems (Dnipro, Ukraine) of a hollow filament cathode based on lanthanum hexaboride (LaB6). The cathode is designed for joint operation with Hall thrusters of various input powers. The emitter material LaB₆ is very promising, because has a high emissivity and low ionization potential. However, to realize all the advantages of considerate material, it is necessary to provide a sufficiently high operating temperature (1400 ° C). Therefore, when developing the filament cathode, special attention was focused on the development and research of one of the key elements of the filament cathode - the heater. Thermal calculations of the hollow cathode were carried out when it was heated with a heater, as well as when the cathode was operating in auto mode. The results of thermal calculations made it possible to identify the shortcomings of the cathode structure and parameters and determine the ways to eliminate them. Laboratory tests of a cathode with a different number of heater thermal shields have been carried out. The results obtained made it possible to provide the required operating temperature of the cathode emitter with a minimum number of heat shields. Laboratory tests of the cathode were carried out both in diode mode (to the external anode) and in conjunction with the ST-25 Hall thruster developed by the company. In the course of laboratory tests of the cathode, the power supplies for the discharge, the keeper, and the heater, which are components of the power processing unit of the Hall thruster, were used. In the frame of experimental studies, a cyclogram of the cathode starting process was obtained, which is necessary to form the Hall thruster starting sequence. The tests carried out confirmed the correctness of the selected technical solutions for the choice of the cathode and its heater. The developed cathode can be used both in low-power (up to 200 W) Hall thrusters and in thrusters with increased input power (up to 5 kW).

PECULIARITIES OF MANUFACTURING OF HOSES FOR INTERFACES OF THERMAL CONDITIONING SYSTEMS OF INTEGRATED LAUNCH VEHICLES

M. Khorolskyi, S. Bigun (Author) — Sat, 06 Nov 2021 00:00:00 +0200

The article describes the peculiarities of manufacturing of corrugated rubber hoses for interfaces of thermal conditioning systems of integrated launch vehicles. The peculiarities are determined by the properties of rubber as a structural material, as well as the technology of moulding of large rubber technical products, namely rubber hoses. Taking into account that the hose manufacturing technology іs closely related to the design of the manufacturing equipment, we consider a completely new approach to manufacturing of high-quality single-diameter rubber hoses of different sizes and lengths in one mould with a possibility for mould adjustment. The new approach suggests that replaceable sections are symmetrically mounted in pairs onto the inside of the upper and lower plates along the axis, whereas replaceable diametral liners are mounted onto the solid part of the core assembly enabling moulding of single diameter corrugated rubber hoses of different sizes. The centres of the projections and cavities of the diametral liners should lie in a single plane with the respective centres of the projections and cavities of the replaceable sections in the lower and upper plates of the mould. The dimensions of the replaceable sections and the diametral liners depend on the dimensions of hoses and the number of corrugations in them. It will help cut costs for production and repair of the manufacturing equipment with less equipment required and improve serviceability and quality of the equipment with enhanced manufacturability and repairability of mould components. Utility model patent No. 143346 dated 27 July 2020 was obtained for the technology of manufacturing of corrugated rubber hoses for interfaces of thermal conditioning systems. The article shows the possibility of boosting the productivity when manufacturing corrugated rubber hoses for interfaces of thermal conditioning systems through production of the second interchangeable core assembly and its preparation for installation and operation in course of hose manufacturing.

HALL-EFFECT THRUSTER ST-25 WITH PERMANENT MAGNET

Sat, 30 Oct 2021 00:00:00 +0300

Results of development and experimental tests of Hall-effect Thruster ST-25 are presented. This thruster is intended for application on small space vehicles. With the purpose of decrease of input electric power in the magnetic system of the thruster a permanent magnet is applied. The permanent magnet is located at the base of the central magnetic core. The permanent magnet provides most of the magnetic induction in the accelerating channel of the thruster, while the side magnets provide precise magnetic field adjustment. Laboratory testing of the ST-25 thruster were realized with application of the preheated hollow cathode which is operated in auto mode at the discharge current 0.5 … 0.9 A. In the process of developing the thruster, its laboratory tests were carried out with a laboratory prototype of the Xenon system for storing and supplying a working substance. The laboratory supply system provided the supply of the working gas to the anode unit 0.65 ... 0.90 mg /s and 0.07 ... 0.10 mg / s to the hollow cathode. The characteristics and parameters of the thruster were obtained using a discharge power supply that has the properties of a voltage source and a power source. The discharge power supply is the part of the flight prototype of the power processing unit. Laboratory tests have confirmed the rightness of the technical decisions stopped up in the structure of the thruster. Methodology of the thruster ST-25 start at the use of preheated cathode and flying prototype of the discharge power supply were improved. Possibility of application of such type of Hall Thrusters on space vehicles with the size of on-board electric power of that is limited to the size 200 - 300 W were confirmed.

PROSPECTIVE TECHNOLOGIES OF DIGITAL IMAGE PROCESSING IN CONTROL OF OBJECT SURFACESROCKET AND SPACE EQUIPMENT

M. Meiirbekov, T. Manko, K. Kozis (Author) — Wed, 27 Oct 2021 00:00:00 +0300

State control method of visual inaccessible surfaces of technical objects was examined by research of digital images which contains information about their state and quality. Received data lets classity compare and mark out the classes of normal and abnormal digital images. Results and conclusion of visual analysis were confirmed by statistical treatment of matrix measurements of digital images. In the context of a lack of a priori data on the in formativeness and statistical regularities of experimental matrices for measuring the brightness of digital images of technical objects being developed and inaccessible for observation, their condition and quality should be monitored in a comprehensive manner and in stages. At the first stage, by visual analysis of digital images, their classification is carried out with the allocation of a class of anomalous digital images and a class of images, the controlled surfaces of which are considered normal. At the second stage, by means of statistical processing of measurement matrices, data are generated for visual - analytical analysis and verification of hypotheses about the state of the controlled surfaces of technical objects and confirmation of the results of their classification by visual examination of digital images. Methods of processing matrices of such experimental measurements are an estimation of their mathematical expectations, variances, correlation coefficients, empirical functions and probability distribution laws. These integrated estimates are informative indicators of statistical homogeneity of measurement samples as random variables. They are used in the design, development and testing of rocket and space technology facilities. As a result of the work, a new method of visual-analytical processing of digital images was proposed to control the surfaces of objects of rocket and space technology during their design and testing.

ADVANTAGES OF HIGH-TEMPERATURE GENERATOR PRESSURIZATION OF LPG TANKS

R. Petrenko (Author) — Wed, 20 Oct 2021 00:00:00 +0300

Propellant tank pressurization systems are one of the most important and science-intensive parts of the propulsion system, the design of which significantly affects the LV mass perfection, the launch complex composition and the scope of its experimental development. The use of LOX-LNG propellants is promising due to the lower cost of LNG compared to kerosene, increased calorific value and other advantages that make it possible to reduce the cost of LV launch. However, in case of developing systems for supplying LNG for propulsion systems, at present (“Starship” launch vehicle, for example), it is not envisaged to use high-temperature generator systems for pressurizing tanks, which have structural simplicity, reliability and minimum weight. The use of these systems in a number of LVs made it possible to significantly simplify the designing propulsion systems, and to improve the energy characteristics of rockets in general. At the same time, the evaporative pressurization system used in Starship LV is known for a number of drawbacks, which significantly complicate the design of the propulsion system and increase its mass. A comparative study of the generator and evaporative systems for LNG tanks pressurization is shown, and their design features and the impact on the labor intensity of creating a propulsion system are considered. The composition of the combustion products was evaluated and the optimal operating mode of the generator was selected. Using a proven calculation method, the main characteristics of the considered pressurization systems were determined, their joint comparison confirms the significant advantage of high-temperature generator pressurization of LNG tanks, in terms of increasing the energy characteristics of the LV.

HIGH PERFORMANCE PROCESSING CLUSTER FOR REMOTE SENSING SPACECRAFTS

Wed, 20 Oct 2021 00:00:00 +0300

Recently, there has been a tendency to complicate real time control algorithms, to process a large amount of information from the satellite payload (optical, radar, communication systems) directly on board and to create highly informative communication lines with both ground stations and other satellites. The conditions of outer space (vacuum, radiation) impose significant restrictions on the computing capabilities of onboard equipment, which is used as an onboard digital computer complex, and lead to a significant increasing in the cost of space components. A high-performance and relatively cheap computing cluster structure of an on-board computer based on widely available single-board minicomputers is proposed, which allows distributing the computing load among several nodes and simultaneously backing up the system. As a component of a computing cluster, it is proposed to use a computing cluster system based on COTS (Commercial off-the-shelf) components, which increases performance by several orders while reducing cost. Calculations have shown that the introduction of redundancy and distribution of computational tasks makes it possible to achieve an MTBF of about 3 years, which is quite enough for the active existence of university satellites. The proposed structure of the onboard computer complex is installed on the university satellite for remote sensing of the Earth in the visible range with controlled optical magnification, after the launch of which it is planned to confirm the reliability of the results obtained in this work. An assessment of the performance and reliability of such a cluster system is given, which has shown the possibility of implementing such a system on a university satellite for Earth remote sensing.

EFFICIENT DESIGN OF AIRCRAFT BRACKET USING TOPOLOGY OPTIMIZATION AND ADDITIVE TECHNOLOGIES

Volodymyr Ivanovich Lipovskyi, Vladyslav Ivanovich Shynkaruk (Author) — Tue, 19 Oct 2021 00:00:00 +0300

The design of an aircraft must always meet opposite criteria. On the one hand, the structure must be strong, rigid, stable and at the same time to have the least weight. The design requirements listed above in modern conditions must be complemented by the requirement of safety increasement of the crew in case of emergency. One of the possible solutions for ensuring safety is creation of structures capable of accumulating impact energy during an emergency landing of an aircraft. Additive technologies have fewer restrictions on the complexity of shape geometry than traditional ones. Modern methods of topological optimization make it possible to determine the direction of power flows in a structure. Based on this data, the optimal design is determined to take into account the requirements of working capacity and minimum weight. The combination of new technologies with topological optimization techniques allows to design parts more efficiently. The article discusses various options of using different approaches of material distribution in a given volume of a part. Topological optimization was performed using the variable density algorithm. This method is used to create a solid and lattice structure of a bracket for wing to fuselage joint of the ATR-42-300 aircraft. A comparison was made between the original bracket, the bracket with a solid structure and lattice structure obtained as a result of topology optimization method. The optimized design options are determined under the requirements of strength and minimum weight in working conditions. The estimation of the energy absorption by the bracket for all three variants of structures under the conditions of an emergency landing was carried out. For the first time, a comparison of the results of topological optimization for a lattice structure and solid structure model of material distribution was performed. The comparison of all options with each other showed that lattice structure is the best design. This type of structure allows to reduce the weight of the original structure by up to 60%. In addition to reducing weight, these structures increase the safety of the crew in case of emergency by increasing energy absorption on impact.

ADVANTAGES OF ROCKET MADE FROM COMPOSITE MATERIAL

J. Lazareva, Y. Tkachov, I. Lazarev (Author) — Fri, 15 Oct 2021 00:00:00 +0300

The paper considers mass estimation of the one-stage launch vehicle with solid propulsion systems built of composite material, namely the calculation of the weight coefficient. The reduction of weight perfection rate is caused by the application of the innovative design and layout solutions, as well as the use of composite materials. We suggest considering of the specific strength of "kevlar" composite material as the most widely used composite material in rocket engineering. At present, the great potential of rocket and aircraft engineering is attributed to the composite materials owing to their attractive mechanical properties. The paper provides examples of the launch vehicles of composite materials, which are currently in operation used in the following countries: USA, France. The paper suggests a solution to the problem of launching of the payload into the orbit on the one-stage launch vehicle with solid propulsion systems, while it is only the two-stage launch vehicle with liquid propulsion systems that is able to manage it. This paper suggests comparing the energetic capacities of the one-stage launch vehicle with solid propulsion systems and two-stage metal launch vehicle with liquid propellant system. The paper also considers a possibility of increasing the length of the combustion chamber of the solid propulsion system, and, therefore, of the whole launch vehicle (without reducing the stability of the airframe), when using the combustible composite case of the launch vehicle with solid propulsion systems. The advantages of using the airframe of the launch vehicle built of composite material are theoretically demonstrated, and the attempt is made to prove that, applying the approaches suggested by this paper, enables addressing the complex problem related not only to energy and mass properties of the launch vehicle, but also to the associated problems - design and ecological ones.

ALGORITHM FOR ASSESSMENT OF FOREST RESOURCES BY REMOTE MONITORING DATA

A. Zakora, V. Sazonov (Author) — Fri, 15 Oct 2021 00:00:00 +0300

The article presents an algorithm for assessing some taxation indicators of forest resources based on remote monitoring data. A software module has been developed that automatically evaluates the quantitative characteristics of forest areas. The proposed method uses the features of the spectral - reflective characteristics of forest vegetation, and the use of filtration makes it possible to take into account the features of the objects under consideration. As data sources, the results of color and infrared digital aerial photography from unmanned aerial vehicles were used. High resolution RGB and NIR (near infrared) camera data were analyzed. The processing of aerial photographs was carried out using gradient methods, filtering algorithms and division of images into zones. The use of vegetation indices as recognition signs, the value of which was calculated based on the spectral brightness coefficients of the red and near infrared ranges, made it possible to reduce the time for identifying the objects of photography. The paper considers both general and specific methods of orthomosaic processing. The possibility of direct assessment of some quantitative characteristics of taxation indicators by using the hidden regularities of the reflective properties of tree crowns contained in the image is shown. The developed algorithm and software module makes it possible to automate the accounting of forest resources, to update the taxation database, to monitor changes in the characteristics of forests, to monitor their condition, to receive objective information on the condition of forest funds as soon as possible. The program is written using the Pycharm development environment. The software block is implemented as a separate module and integrated into the open geographic information system QGIS.

USE OF STEP MOTORS IN ANTENNA DRIVES FOR SOFTWARE SUPPORT OF THE EARTH STATION SPACE VEHICLE

A. Dymchenko, І. Savchenko (Author) — Wed, 13 Oct 2021 00:00:00 +0300

In connection with the rapid growth of programs for the creation and operation of small-sized student satellites, it becomes necessary to implement a radio link earth station - spacecraft using software algorithms technologies and physical implementation of control mechanisms for automated satellite tracking systems with an antenna earth station. Since such systems operate in different weather conditions, mainly at different wind speeds, it is necessary to provide the ability to withstand such loads. Today, worm gearboxes are used, which have a self-braking effect, but they are expensive to manufacture and have low efficiency. Therefore, to ensure the flexibility and versatility of the control system, it was decided to replace the worm gearbox with a conventional two-element gearbox and a stepper motor. This implementation makes it possible to reduce the number of nodes with static mechanical transmission ratios (gearbox with a given transmission ratio) and replace them with nodes with the ability to programmatically control both the rotation speed and the transmission ratio itself. The main advantage of such implementations of the control system is the presence of a constant torque on the motor shaft in the operating mode at any speed of rotation, which allows maintaining the smooth movement of the antenna system even at small angles of movement without oscillatory effect. This implementation method allows using this approach as part of antenna-based systems with a radiation pattern from 5 to 30 degrees.

ON THE INFLUENCE OF THE GAS DUCT SHAPE ON THE ACOUSTIC LOADS VALUE AT THE LIFT-OFF OF THE LAUNCH VEHICLE WITH A SINGLE NOZZLE

S. Nikolin, G. Sokol, V. Frolov (Author) — Wed, 13 Oct 2021 00:00:00 +0300

The gas-dynamic type of launch from open launch sites is mainly used during the launch vehicles launching. Its accompanied by the occurrence of huge gas-dynamic and acoustic loads that affect both the payload and ground structures in general. The implementation of gas ducts with gas reflectors with a special shape and dimensions is one of the ways to reduce these loads. The purpose of this work is implementation of the numerical method of simulation to demonstrate changing acoustic loads when the geometric parameters of the gas duct change. The simulation of the gas-dynamic launch of the launch vehicle from the launch pad, where the spent jets are discharged with the help of a gas duct, has been conducted (Fig. 1, 2). The calculations were performed for the case when the distance between the nozzle exit and the gas inlet is 9400 mm. The Mach number at the nozzle exit is 3.95, and the temperature is about 1820 K. The nozzle pressure ratio is 0.48. In the current work, the depth of the gas duct (h) applies the values – 5500 mm, 6500 mm, 7500 mm, while the angle of inclination of the deflector (φ) is - 61.9^о, 66.6^о and 70^о, respectively. In this paper, the simulation of gas-dynamic processes is carried out using non-stationary Reynolds-averaged Navier-Stokes equations using the k-ω SST turbulence model. Broadband noise models were used to assess acoustic loads.

Based on the calculation results, the distributions of the Mach number, pressure, temperature, and the acoustic power level inside of the gas duct are constructed. It was found out that with increasing of the gas duct depth the acoustic power of the jet remains unchanged, but the acoustic power level of noise radiation in the environment decreases. Calculations have shown that the shallower the gas duct depth, the higher the acoustic power level. For example, at h = 7500mm the average acoustic power level in the environment is in the range of 90 ÷ 110dB, then at h = 5500mm it is already 110 ÷ 130dB.

MATHEMATICAL MODEL FOR DETERMINE OF THE MESH BUBBLE POINT PORE DIAMETER

Mykola Olehovych Pozdnyshev (Author) — Wed, 13 Oct 2021 00:00:00 +0300

The article presents mathematical models for determining the bubble point diameter of the pores of meshes with micron sizes square cells of plain and full twill weaving. Analyzed are mathematical models developed by a number of researchers to determine the bubble point pore diameter of the meshes and their point pore pressure. The analysis of the mathematical models showed that they were developed on the basis of a number of assumptions that, to varying degrees, take into account the spatial shape of the mesh cells and the physicochemical processes when the free surface through the mesh. This undoubtedly affects the accuracy of analytical calculations that are based on the use of these models. In the presented work, mathematical models have been developed that take into account the complex spatial shape of the wires from which the mesh is made. Mathematical models have been developed for plain and twill weaving meshes. When developing mathematical models, it was assumed that the free surface is formed on a hole with elliptical edges. In this case, it is assumed that the points of contact of the free surface of a plain weave mesh correspond to the most distant points of the projection of the mesh cell. For full twill meshes, taking into account the structure of their weaving, it is assumed that the free surface is formed on two adjacent cells. The influence of the contact angle between the mesh surface and the working fluid was taken into account by analyzing the spatial shape of the mesh wires. The developed models make it possible to take into account the effect of liquids with a contact angle from zero to 90 degrees. Simplified mathematical models of the meshes have also been developed for the case of perfect wetting of the mesh surface with a liquid, when the contact angle is zero. The obtained mathematical models can be used in the design of capillary phase separators of liquid acquisition devices in zero gravity of spacecraft, as well as in the calculation of capillary devices of various technical systems, such as heat exchangers, gas-liquid mixers, chemical reactors, bubble filters, etc.

THEORETICAL RESEARCH OF EXPERIMENTAL MEASUREMENTS USING PROBABILITY DISTRIBUTION FUNCTIONS

O. Klymenko, D. Astakhov, S. Klymenko (Author) — Wed, 13 Oct 2021 00:00:00 +0300

The statistic has analyzed the current development of mathematical statistics, how to be victorious in the case of the inoculation of mass manifestations, as they are represented in the eyes of the population with unprecedented statistical authorities. Measurement revenge information about the stan of the controllable objects and technological processes. In order to obtain information, it is necessary to process, re-work according to the rules or algorithms and assess indicators that characterize the state of control, or the level of compliance with the norms. Even if the results of control, including non-linear control with low-grade events, and the results of measurement – orderly values, then without the knowledge of their authorities it is not possible to process the control and prepare data for the purpose of solving the problem about the control unit. Mathematical methods describe the statistical regularities of different types of values and values, the rules of their re-implementation in the development of specific problems – all the principles of the theory of definitions. The algorithm for the formulation of the experimental vibration with the logistic law of the distribution of the given parameters has been broken down. Introduced the theoretical foundations of the Smirnov-Kramer-fon-Mizes criterion. This criterion in the classical mathematical statistics is used to determine the theoretical and empirical function of the distribution of values. Conducted theoretically, the vibration of the growth of the age was carried out, on the basis of the prompted theoretical and empirical functions of the development of the change in the quality of the three types and the correlation of the same background with the additional criterion of the Mixture. Previously, they showed that the test is analogous to the criterion of Smirnov-Kramer-fon-Mizes is we will forgive the victorious for short, so on the most vibrant ones.

RATIONAL HEAT RECOVERY TECHNOLOGIES OF VENTILATION SYSTEMS FOR HEATING BUILDING SYSTEMS

G. Olishevskiy, I. Olishevskiy (Author) — Wed, 13 Oct 2021 00:00:00 +0300

Analytically analyzed and substantiated rational technologies for efficient utilization of heat energy of the ventilation system for hot water supply of the building during the cold period. The first technology provides for the use of a heat pump and a heat accumulator, and the second technology - a two-stage plate recuperator with a guarantee of non-freezing of heat exchange surfaces in both cases. Using the developed methodology for calculating the parameters of the ventilation system, it was determined that the use of a scheme with a heat pump and a heat accumulator would reduce the consumption of equivalent fuel by half compared to using a gas water heater at the same facility. A technology has also been developed that makes it possible to determine the rational area of a plate recuperator in the ventilation system of a building, provided that the heat exchange surfaces are free from frost without using additional energy resources in the heating system. The proposed technology considers the use of a two-stage scheme, in which the recuperator consists of two sections. In the case when the outside air temperature is higher than the critical one, then both sections work sequentially, which provides a rational heat exchange area, and, accordingly, a rational value of the recuperation coefficient. If the outside air temperature becomes below the critical one, then one of the sections is turned off, reducing the heat exchange area of the recuperator to the required value. This value of the heat exchange area is determined based on the condition of non-negativity of the temperature of air leaving the environment. The developed technology of heat recovery from the ventilation system using a two-stage recuperator ensures its reliable and continuous operation without freezing of heat exchange surfaces and with rational values of the recuperation coefficient (from 80 % higher), which guarantees a combination of energy efficiency and compact design. Having analyzed the features of the heat recovery technology using a heat pump and a heat accumulator in the cold season, as well as using an air conditioner and a heat accumulator in the warm season, we can say about the justified need to create a unified year-round heat recovery technology for a hot water supply system using a heat pump and heat accumulator.

ЧЕРГОВИЙ КРОК МОЛОДІ ДО НОВИХ КОСМІЧНИХ ДОСЯГНЕНЬ

Ірина Володимирівна Федоренко (Author) — Fri, 08 Jan 2021 12:00:03 +0200

Традиційною подією у науковому житті України щорічно стає Міжнародна молодіжна науково-практична конференція «Людина і космос», яку проводять під егідою Міжнародної федерації астронавтики Національний центр аерокосмічної освіти молоді ім. О. М. Макарова, Дніпровський національний університет ім. Олеся Гончара, ДП «Конструкторське бюро «Південне» ім. М. К. Янгеля та інші установи і навчальні заклади аерокосмічного профілю України та зарубіжжя.

Ініціаторами щорічного проведення молодіжної науково-практичної конференції «Людина й космос» виступили Національний центр аерокосмічної освіти молоді ім. О. М. Макарова, Державне космічне агентств України (ДКАУ), Національна академія наук України (НАНУ), Міністерств освіти й науки України.

DIRECTIONS FOR IMPROVING STRUCTURAL AND LAYOUT SCHEME OF SPACE MAIN PARTS

D. Danilchenko, N. Dron (Author) — Fri, 30 Oct 2020 00:00:00 +0200

Modern research tasks and requirements for the means of their implementation, namely, spacecraft, determine new trends in the development and improvement of their protection means at the stage of preparation for launch and injection into orbit, such as space main parts, giving them new functionality. They are significantly reflected in their design and layout schemes. This article examines the structural and layout schemes and provides a classification of space main parts developed by the Design Office Yuzhnoye, SpaceX, Rocket Lab and other foreign analogues, as well as their main differences, including systems, subsystems, docking schemes for the fairing flaps and materials used. On the basis of the considered advantages and disadvantages of the existing space main parts, new directions for the development of their structural and layout schemes were determined, in particular, the use of materials with high specific strength and rigidity, reusable space rockets, including their component parts – payload fairing flaps. A variant of the improvement of the component part of the rocket for space purposes, namely the space main part, is also presented, which consists in its reusability due to the refinement of the upper stage, equipping with parachute systems and locks for opening and closing the flaps of the reusable fairing, one of the improved structural and layout schemes, its advantages and disadvantages and how it works. New tasks for the use of space warheads have been identified, which consist in their concomitant use for the removal of a burial site into orbit or the return of a payload to the Earth's surface. Directions for further research are given, which consist in improving the systems for dividing the flaps of the payload fairing and structural layout schemes in general.

THE DEVELOPMENT OF EFFECTIVE SYSTEMS FOR CONNECTING AND SEPARATING OF COMPARTMENTS

D. Bondarenko, А. Krivoruchko, P. Khorolskiy (Author) — Tue, 27 Oct 2020 00:00:00 +0200

This article is about the devices and systems that are designed to connect and separate structural elements of missiles, in particular, their compartments, in conditions of limited access to the joint. When designers create rocketry, they meet with a number of problems, since it has to be multifunctional, placed in a limited volume and at the same time remain technological. Creating detachable joints of missiles compartments is a simple and difficult task concurrently. It becomes a difficult task when technological equipment, modes of operation and internal components of a missile impose a number of restrictions on the detachable joint. Sometimes these restrictions come to the point that it is necessary to create such a detachable joint, which could connect and separate compartments remotely without access to the joints themselves. And at this moment, all the variety of technical solutions becomes useless without any improvements, since all of them are intended for connection in conditions of normal access to the joint. Thus, the main drawback of the generally known solutions is the lack of functionality, which means impossibility of remote (without access to the joint) connection and separation the detachable joints. The purpose of this article is to develop a design of the detachable joint, which provides remote connection, and separation of the missile structural elements. Using as examples various variants of the devices and systems for connecting and separating structural elements of missiles, various options of the most effective solution of the specific problem, mentioned above, are considered. The analysis is carried out and recommendations are given for their designs adaptation to multiuse without the possibility of maintenance. These recommendations will make it possible to further solve problems such as, for example, connecting a jettison able aerodynamic fairing with a missile, payload with a compartment, or compartments with each other – automatically, without the participation of technical personnel in the work area, which, accordingly, will reducing the time for preparing and launching missiles. Scientific novelty lies in the development of system, namely, remote connection and disconnection of compartments in conditions of limited access to the joint, as well as increase in manufacturability and reduction of disturbances during disconnection of compartments.

YUZHNOYE`S POSITION IN WORLD PLANS FOR MOON EXPLORATION

Lilia Olegovna Velychko, Evgenia Alexandrovna Ermolenko (Author) — Mon, 30 Dec 2019 00:00:00 +0200

The article discusses the lunar programs of leading countries of the world: EU, India, People’s Republic of China, South Korea, Israel, Russian Federation, Japan, USA, as well as possible direction of cooperation between Ukrainian cooperation and mentioned countries. The US lunar program is the most attractive. NASA invites private companies which can become Yuzhnoye State Design Office partners. Perspective payload delivery means into lunar orbit are proposed: Space Launch System, Falcon Heavy, Straship. Marketing strategy was developed to achieve economic efficiency of the space launch system operation project, designed for payloads injection into the lunar orbit (with Mayak launch vehicle family, developed by Yuzhnoye State Design Office, as an example) due to covering all possible segments of commercial, as well as government launch market. At the same time, comparison of price and performance characteristics of space transportation services into low Earth orbit is shown as of 2019. The prospective demand for Mayak launch vehicle family within the framework of the US state program for the development of the Moon was determined. According to the results of the marketing research, it can be concluded that with the price of about 3 000 US dollars for launching 1 kg of payload into low Earth orbit (from 70 to 330 million US dollars for launch), Mayak launch vehicle family have the advantageous position on the launch market into low Earth orbit and lunar orbit in comparison with the competitive positions of other ILVs in this market segment.

STABILITY ANALYSIS OF SOFTWARE MANIPULATOR MOVEMENTS USING MATHCAD

Natalya Sergeevna Ashchepkova (Author) — Mon, 30 Dec 2019 00:00:00 +0200

Abstract. The method of the stability analysis of the manipulator program movements with use of Mathcad applied programs package is offered. On the basis of the manipulator’s kinematic scheme, the matrices of homogeneous transformations of Denavit Hartenberg are formed and a mathematical model of the extended control object is drawn up. An outline of an extended object control system consisting of a manipulator and an actuator is presented. For example, the linear equations of the manipulator, actuators, meter and controller are considered. The task of synthesizing the manipulator control algorithm is to determine the coefficients of the matrix transfer function of the controller that satisfy the conditions of stability and quality of transients. Mathematical modeling of manipulator programmatic movements was performed using the Matchad application package. The analysis of simulation results allows us to evaluate: manipulator workspace, control system performance, grip positioning accuracy, dependence of grip positioning error on the nature of load and the law of motion. A change in the dynamic characteristics of an extended control object causes a change in the controllability of systems, for the considered example rang Q = 2, i.e. the system is fully controllable.

This method can be used to analyze the manipulation of the manipulator at the design stage; allows to determine the influence of design, kinematic and dynamic parameters on the manipulation of the manipulator and perform mathematical modeling of the manipulator motion. Calculation examples are given that confirm the expediency and effectiveness of using the Mathcad application software package to solve this type of problem.

RECOGNITION OF AGRICULTURAL LANDS BASED ON MEASUREMENTS OF A VEGETATION INDEX

Sergey Aleksandrovich Bartalev, Alexander Leonidovich Zakora (Author) — Mon, 30 Dec 2019 00:00:00 +0200

The paper presents a method for assessing the utilization of arable land based on measurements of the NDVI vegetation index, calculated from images of a MODIS spectroradiometer from the Terra satellite. The work involves the development of a software module that performs the automatic classification of agricultural land into utilization classes.An algorithm and programmatic block are worked out for classification of degree of used of agricultural lands. Educating of classifier is conducted by means of algorithms of computer-aided instruction.

For an analysis data of measuring of vegetation index of NDVI were used for every week 2017 year, got in the system Vega the vehicle of MODIS. For testing of algorithms a selection was used from 1026 vectors of signs (agricultural lands) equipartition on different areas. Breaking up on teaching and test selections was produced with maintenance of balance between areas. A job of the program performance is a mark of class for every entrance vector, characterizing the use of agricultural lands. The use of measuring of vegetation index allowed to automatize classification of used of the fields. For the fields, vector of values of NDVI that is had admissions of measuring, the algorithm of filling of admissions is applied, that allowed to use these the vector for classification. The features of development of vegetation were taken into account depending on a geographical location. The use of algorithms of computer-aided instruction gave next results: kNN is exactness of classification of 82%; SVC is exactness of classification of 78%; Random Forest is exactness of classification of 85%; GBT is exactness of classification of 86.307%. The most high results are got with the use of algorithm of GBT - 86% of the correctly classified fields. Programmatic block realized as a module ready for integration in the system Vega.

WELDING ALUMINIUM ALLOYS REFRACTORY MODIFIERS TREATMENT – THE EFFECTIVE METHOD FOR CHARACTERISTICS INCREASING

Mon, 30 Dec 2019 00:00:00 +0200

The effect of modification by refractory dispersed compositions on the grain structure and properties of welded aluminium alloys is determined. Aluminium alloys of the Al-Mg-Mn system of chemical composition were studied: 4.8-6.0% magnesium, 0.3-0.5% manganese; 0.45 – 0.90% iron; aluminium - base. The iron content corresponded to the pre-eutectic and post-eutectic compositions of the aluminium-iron system. Titanium carbide (TiC) modifier powders with a dispersion of 1-5 microns obtained by the method of plasmachemical synthesis. The microstructure of the alloys was studied using MIM-8 and Neophot-2 optical microscopes. The strength properties of the alloys were determined using the MUP-20 machine. Production of samples was carried out according to GOST 1497-84 and GOST 9454-80. Fluidity was determined by the spiral sample method. The properties of alloys before and after modification were investigated. Improved technological properties of aluminium alloys after modification. Increased fluidity in AMg5 and 1420 alloys by 1.5% and 6%, respectively. The obtained homogeneous dispersed structure of aluminium alloys after modification. The strength properties of modified alloys are increased by20 %. Experiments were conducted on the effect of the charge type on the structure and properties of technically pure aluminium and aluminium alloys AMg5 and 1420. The advantage of solid charge in the smelting of aluminium ingots in reducing porosity and grinding grain in comparison with the use of liquid charge is established. The effective effect of the refractory modifier of titanium carbide on the properties of aluminium alloys is proved.

INFORMATION TECHNOLOGY FOR DECISION MAKING SUPPORT IN MONITORING TASKS MENTAL STATE OF PERSONALITY

Mon, 30 Dec 2019 00:00:00 +0200

The article analyzes the current state of development of information technologies of psychometric state of the person, features of definition of mental states of the person and methods of observation of changes of the state of the person. The analysis of information technologies of decision support in monitoring tasks concerning the state of the person is carried out. Eysenck computer test information technology has been developed. The results of the tests tested using Eysenck's computer psychometric testing were conducted. According to the test results, algorithms for secondary processing of test results were developed during testing several times and during the process of monitoring the subjects. Based on the results of the study, information technology for decision support in personality monitoring tasks was developed based on the Eysenck computer version of the test. According to the results of the study it is determined that it is necessary to use different approaches to be processing the test results, which will confirm the sincerity of the subject. Therefore, the article discusses several criteria for determining the quality of test results and their sincerity. It has been determined that computer-based psychometric monitoring is aimed at objectively assessing changes in mental state based on the results of retesting. The research in the tasks of monitoring the mental state of a person is to apply the processing of statistical psychometric measurements (initial processing of test results), quantitative assessment of changes in psychometric parameters and identify their trends in long-term observation. Data from such measurements indirectly contain information about changes in the mental state of the subject.

ANGULAR MOVEMENT PROGRAM CALCULATION PROCEDURE SPACECRAFT WHEN TAKING THE SURFACE OF THE EARTH IN AREA MODE

Mon, 30 Dec 2019 00:00:00 +0200

Currently increased interest in satellite images of the Earth's surface with high resolution terrain (1 to 10 m). To obtain such images, you must use a long focus optical system (OS) having a limited field of view that does not allow the images of the large width. To increase the effectiveness of shooting in modern space systems (SS) Earth observation provides the opportunity after shooting a segment of the Earth's surface to redirect the OS to another area and spend it shooting. With sufficient speed shift OS it is possible to survey two or more adjacent parcels, which is almost equivalent to the corresponding increase in the width of the field of view of the removing apparatus. In this connection there is the task of restoring the OS, which is solved by the use of appropriate hardware and software control the angular movement of the removing apparatus. When creating the SS there is also the need to solve the following tasks: calculation of the program angular motion in a given length of the removable sections and a predetermined number of adjacent strips to be shot, with the purpose of definition of system requirements, spacecraft (SC) control and calculation under given characteristics of the system orientation of the SC possible number of the maximum length and remove adjacent portions of the surface of the Earth. To solve these tasks the mathematical model software of angular motion of the SC. Given the necessary initial data, mathematical model and method of calculation of kinematic parameters of a software angular motion of a SC in the mode of area highway shooting adjacent sections of the Earth's surface located at a predetermined distance from a trace route SC; examples and results of numerical calculations of the programmes angular motion by moving the instrument in remote sensing.

THE ISSUES OF CHEMISTRY AND TECHNOLOGIES OF RESIN MIXTURES FABRICATION FOR INTERNAL HEAT-PROTECTIVE COATING OF ROCKET SOLID FUEL ENGINE

Tamara Antonovna Man’ko, Kristina Viktorovna Коzis (Author) — Mon, 30 Dec 2019 00:00:00 +0200

One of specific features of rocket engineering – is the high rate of sophistication and renewal of structures due to constantly growing operational and technical specifications imposed to them. Every generation of rocket and space products features a new complex of design and processing parameters and new materials possessing higher properties. It is impossible to resolve the entire scope of design and processing tasks in course of development, creation and operation of spacecraft without extend development and infusion of new materials which possess a number of required characteristics imposed to state-of-the-art technology products. The most widespread and sophisticated structures of modern technology – are solid-propellant rocket motors (SPRM) made of polymer composite materials. One of the major tasks associated with their creation is development of the internal thermal protection coating of solid-propellant rocket motor casing. State enterprise Yuzhnoye Design Office named after M.K. Yangel is currently carrying out works on creation of solid-propellant rocket motors. Development of their internal thermal protection coatings using mainly domestically produced materials with specified requirements is a scientific and technological task of high importance which confirms the relevance of dissertational research.The article is devoted to the analysis of components and ingredients for rubber compounds, which provide the properties and basic functions of the thermal protective covering of solid propellant rocket engine. The article shows the main results of the work related to the development of prescribed composition and technology of manufacturing of elastomeric material which used in the manufacture of internal heat-resistant coating of solid-propellant rocket engines made of polymer composite materials.

THE MODEL OF A RADIO LINK "SPACE-TO-EARTH" WITH MORE INFORMATIVE FOR A LOW ORBIT SATELLITE

Mon, 30 Dec 2019 00:00:00 +0200

A proposed the model of a radioline “space-to-Earth” with more informative for a low orbit university nanosatellite. The radioline is modeled on a antenna of the high-frequency S-band. At present time, the tasks of creating radiolines “space-to-Earth” in the conditions of limited energy of satellites with more informativeness (for telemetry radiolines and information radiolines) constantly require increasing their capabilities. Various options are being developed to implement such a solution, ranging from increasing the data transmission time due to repeaters and developing new encoding methods and increasing the bandwidth of radio lines. One solution is to use middle or high gain antennas.

The model of a radioline is designed on the basis of the high-frequency (S-band) antenna. The calculations were carried out according to the international format of the AMSAT-IARU-Link-Model program. The calculation of the proposed the model consists of three basic conditions: the greatest loss of energy of the radio signal in free space, equivalent to isotropic radiating power and quality factor of the receiving station. The proposed model is built on the basis of a phased antenna array with a gain of 12 dBi for transmit from nanosatellite, the gain of the receiving antenna is 35 dBi. The results showed the ability to transmit up to 50 images of the Earth's surface per day. The use of a phased array antenna and the transition to the S-band allowed with smaller dimensions to increase the antenna gain and the rate of information transmission in communication sessions.

GROUND OF RATIONAL TECHNOLOGY OF UTILIZATION OF WARMTH OF THE SYSTEM OF CONDITIONING FOR THE HOT WATERSUPPLY

Gennady Sergeevich Olishevskyi, Ilya Gennadevich Olishevskyi (Author) — Mon, 30 Dec 2019 00:00:00 +0200

Rational technology of effective application of thermal accumulator in the system of conditioning and
hot water-supply of building in a warm period of year is analytically analyzed and grounded. Analyzed the
possibility of applying such an unconventional method as daily accumulation of thermal energy of the building's
air-conditioning system during the warm period with its subsequent use in the hot water system. Two technologies
for heat recovery of the air conditioning system for hot water supply of a building using a heat accumulator were
investigated: with a constant volume of heat accumulator and variable condensing temperature of the refrigerant
of the air conditioning system depending on the outside air temperature and heat recovery technology with a
variable volume of heat accumulator and constant temperature condensation temperature of the refrigerant
system conditioning. The research results showed the most efficient technology for utilization of heat from an air
conditioning system with a variable volume of a heat accumulator, which is 35% more cost effective than a
technology with a constant heat accumulator cost of reference fuel. The possibility of real application of these
technologies, both in individual houses and apartments, was also grounded. Using the developed automated
method, it was certain that application of thermal accumulator in the complex system of conditioning and hot
water-supply in a warm period would allow assured to provide by hot water of users due to the system of
conditioning and will economize from 74% to 82 % conditional fuel as compared to a chart with a caldron and
conditioner without a thermal accumulator.

DEVELOPING AND CREATION OF GROUND TESTING SIMULATOR FOR ORIENTATION AND STABILIZATION SYSTEM OF POLYITAN NANOSATELLITES

O. Padun, Y. Kovalenko, B. Rassamakin, V. Ostapchuk, A. Pynchuk (Author) — Mon, 30 Dec 2019 00:00:00 +0200

The article under the heading "Developing and creation of ground testing simulator for orientation and stabilization system of PolyITAN nanosatellites" is devoted to the research of methods of developing of the specialized simulator for the nanosatellite orientation and stabilization system ground testing. This problem is showed on the example of simulator developed in the National Technical Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute”. Ground testing of the orientation and stabilization system is critically important phase of the pre-flight preparation of the nanosatellite. In order to provide precise tests, the simulator described in this article was developed. Objective of the simulator is to create targeted magnetic field in assured volume, where flight of the nanosatellite is imitated, stabilization and orientation performances are tested. The introduction describes experience of the PolyITAN team in developing of nanosatellites, the tasks of the first two nanosatellites - PolyITAN-1 and PolyITAN-2 are revealed, the actuality of this research is highlighted. The main part reveals the order of development of the simulator for orientation and stabilization system ground testing in gradual and sector-wise way. First part shows construction decisions in the simulator’s configuration to ensure accomplishment of the simulator’s objective. Second part describes calculation of the number of turns and the diameter of the wire to provide required value of the modulus of the vector of magnetic field induction, which is created by the simulator. Next part is devoted to calculation of power required for power sources, increment of magnetic field induction as a function of the current increment is provided, what is very important for power source selection. Next part is a research of the uniformity sphere - working space of the simulator, which must provide enough volume for testing of the 3U nanosatellites of CubeSat format. Final part describes control system of the simulator.

INFORMATION-MEASURING SYSTEMS FOR ELECTRICAL PROPULSION UNIT

Sergey Aleksandrovich Pletin, Alexander Nikolaevich Petrenko (Author) — Mon, 30 Dec 2019 00:00:00 +0200

Considered electric propulsion systems (EPS) based on the Hall effect. Structure of EPS includes hall thruster (HT), xenon feed system (XFS), power processing unit and automatic control and monitoring system. The task is to design information-measuring system (IMS), which allows measurement of the current settings of EPS, conduct their mathematical processing and registration for further analysis. EPS is a complex physical system consisting of subsystems within which different physical processes. These processes are characterized by a large number of parameters and characteristics to be measured and controlled in the process EPS. Listed EPS parameters that should be measured in the operation of system. Determined informative signs of laboratory and onboard subsystems EPS. The necessity of development of information-measuring system and the need to create two different IMS - for use in laboratory equipment for research and testing of subsystems and EPS use in an onboard system management and control. Laboratory IMS provides measurement parameters and test conditions in a vacuum chamber; modes of power processing unit; XFS modes; EPS temperatures subsystem (anode, cathode, supply system, power conversion system); thrust of hall-effect thruster and forming control signals for power sources, flow of propellant and laboratory equipment. Onboard IMS provides measuring current and voltage discharge between the anode and the cathode; valve current of XFS; high and low level pressure of XFS; the temperature of the anode block, cathode, power processing unit.Formulated the tasks performed by the laboratory and on-board IMS. Made choice of hardware implementation of the IMS. The work on the creation of software for the operation of the IMS.

EVALUATION OF THE RELIABILITY TEST RESULTS OF A ROCKET ENGINE BASED ON A LOGICAL-PROBABILISTIC METHOD

Sergey Mikhailovich Podolchak (Author) — Mon, 30 Dec 2019 00:00:00 +0200

A logical-probabilistic method for evaluating the test result is proposed, which is based on the theory of evidence of Dempster-Schafer with some assumptions that do not affect the final result. Currently, there is an acute question of creating new types of rocket technology in connection with a change in the situation on the international and domestic market. When creating new samples, it is necessary to pay special attention to the level of their reliability, but also remember to take into account the financial component of projects for the development and manufacture of products.

In this regard, research is currently being conducted not only in the direction of increasing the reliability of complex technical systems, which include rocket engines, but also in reducing the cost of their refinement. One of the research options in this direction was proposed by the author in this work.

The aim of the work and research as a whole was to demonstrate the capabilities of the chosen method for evaluating the test results, according to which it would be possible to draw conclusions about the success of the tests themselves.

As studies have shown, the logical-probabilistic method for evaluating test results based on the Dempster-Schafer theory of evidence, due to the lack of a priori information, can be used in the development of new rocket engine models, but only in a narrow direction. More widely, this method can be used in the design of products based on accumulated experience (amount of information) on existing analogues. Dempster-Schafer proof theory can be applied at earlier design stages, but only in combination with other reliability models.

GROUND-BASED EXPERIMENTAL TESTING OF ELEMENTS OF AUTOMATION OF PNEUMATIC-HYDRAULIC SYSTEMS OF ROCKET AND SPACE TECHNOLOGY

Alexander Nikolaevich Ponomarov (Author) — Mon, 30 Dec 2019 00:00:00 +0200

The design and production of sophisticated technical systems, which include modern rockets and other aircraft, requires their reliability and trouble-free operation. To achieve the required level of reliability of aerospace products, a wide variety of test methods are applied at all stages of the life cycle. One of the most important systems of the launch vehicle is the pneumatic hydraulic power system of the liquid rocket propulsion system. Development of new and improvement of existing methods of control and diagnostics is one way of increasing the design and technological reliability of products of aviation and space technology. The use of functional diagnostics systems for bench and flight tests significantly increases the reliability and efficiency of space rocket technology. Researches are directed on increase of a level of reliability of products of aerospace branch. Application of systems of functional diagnostics is described at bench tests. The results of experimental researches of elements of automatics of pneumatic hydraulic power supply systems of liquid rocket engines are considered. The technique of processing of experimental data of a pulsing-acoustic method of diagnostics with use of the mathematical technology of recognition of images is presented. Deciding rules of recognition of a technical condition of object of diagnosing by results of tests are resulted. The developed method with a high degree of accuracy allows to determine the technical condition of the object of diagnosis as defective or to detect the presence of characteristic defects. Experimental testing and the proposed method of processing the results showed the efficiency of the method.

PROSPECTS OF ANISOGRID LATTICE STRUCTURES USING IN ADAPTERS OF LAUNCH VEHICLE

Vladislav Arkadiyovych Proroka, Vladimir Ivanovich Lypovskyi (Author) — Mon, 30 Dec 2019 00:00:00 +0200

The efficiency of using anisogrid lattice structures in launch vehicle designs, in particular in payload adapters, is investigated. On a specific example of the design of the adapter, which is in operation, it is compared with an anisogrid adapter, which is made of different materials - composite, made by winding, and metal using additive technologies. The performance of the adapter was evaluated by the criterion of minimum mass, subject to the requirements of strength and stability. The initial geometric parameters of the anisogrid lattice structure were determined under the condition that the critical stresses are equal for the symmetric and asymmetric cases of stability loss for the structural orthotropic shell model. Calculations and comparisons were made for composite materials - fiberglass, carbon fiber, organoplastic and boraluminium, as well as metal - AMG6M, BT20. Checking the geometrical parameters calculated on the model of structural orthotropic shell showed that they do not meet the requirements of strength and stability. The choice of geometric parameters of a working adapter design is made by numerical experiment with finite element method. The geometry of the lattice structure of the adapter was parameterized to ensure the variability of two geometric dimensions of the cross section of the longitudinal rib and two geometric dimensions of the cross section of the upper frame. The numerical experiment was performed for the constructions made of carbon plastic and for metals AMG6M, BT20. The results of the calculations showed that the anisogrid lattice structures give a gain on the weight of the adapters, which is up to 50% compared to the designs in operation.

MATHEMATICAL MODEL FOR SOLVING THE NAVIGATION PROBLEM AND ANGULAR ORIENTATION SPACECRAFT

Ilya Andreevich Sidorov, Alexander Alekseevich Manoilenko (Author) — Mon, 30 Dec 2019 00:00:00 +0200

Currently, there is an increased interest in the creation of strapdown inertial navigation systems (SINS), which make up the information core of modern airborne systems for the orientation and navigation of spacecraft (SC). An urgent problem arises, which is associated with the development of high-precision algorithms for estimating and filtering data from the sensors of the SC motion parameters, the mathematical model of the SINS, calculating its errors and analyzing the effect of errors on the characteristics of the navigation system and orientation of the SC. A mathematical model is proposed for solving the problem of navigation and angular orientation of a small SC equipped with electromagnetic control elements, taking into account the filtering of “noisy” magnetometer data. The requirements are set for the accuracy of the angular orientation and stabilization of the SC in the mode of maintaining the triaxial orientation of the SC in the orbital coordinate system (OCS) and for the duration of the damping mode of the angular velocities obtained by the SC during separation from the launch vehicle (LV), and the mode of the initial construction of the triaxial orientation of the SC in OCS. The mathematical model includes: a model of the motion of the center of mass of the SC in the osculating elements of the orbit with specified parameters, a model of the angular motion of the SC around the center of mass, a model of the Earth’s magnetic field (EMF) and a model of filtering magnetometer data. As an arithm for filtering data from a magnetometer on the components of the magnetic induction vector of the EMF, a one-parameter algorithm of exponential smoothing (exponential moving average) is used, which belongs to the class of first-order filters with an infinite impulse response. The results of numerical simulation of the dynamic processes of navigation and the angular orientation of the SC after separation from the LV taking into account the filtering of magnetometer data by the method of exponential smoothing using mathematical models are presented, and the accuracy of the angular orientation and stabilization of the SC is estimated.

TO THE CALCULATION OF ACOUSTIC FIELD CHARACTERISTICS FOR QUADCOPTER PROPELLERS

Mon, 30 Dec 2019 00:00:00 +0200

The work defines the area of use of unmanned aerial vehicles (UAVs) of the type of quadrocopter and calculated the acoustic field of propellers in order to reduce the level of noise at some distance. The main sources of noise, which are the hubs of the quadrocopter, are considered. The first samples of UAVs appeared in the middle of the last century as a separate type of promising weapons, but now quadrocopter,began to be actively used in the civilian sphere. The theory of the sound field of the aircraft's air propeller, which was proposed by L. Gutin to simulate the noise from each of the chochire screws of the quadrocopter, was carried out. A mathematical model has been created for calculating the total acoustic field all the of quadrocopter screws. The analysis and the defined area of use of UAVs of type quadrocopter and the calculation of acoustic field of screws is given in order to reduce the noise level at some distance. The authors conducted an analytical review of the existing models of UAVs and quadrocopters, considered general examples of use of quadrocopters, their purpose and scope of application. On the basis of analytical review of constructions the fundamental scheme of quadrocopter for researches is given. The article is driven by the principal scheme of the chosen quadrocopter with the description of its main nodes. Based on the results of calculations, the noise distribution schedules of different frequencies in the space are constructed. The results from sound pressure levels for each of the five harmonics. Description of direction of acoustic fields on separate frequencies each of harmonics is constructed using the Besselyu function. Mathematical calculations have been performed in MathCad 2015. There are two forces on each screw element: thrust and resistance of the rotary motion. From the Basic Law of mechanics it follows that this element, in its turn, influences the environment with equal magnitude and opposable directed forces.

SYNTHESIS OF AN ADAPTIVE AUTOMATIC SYSTEM OF AIRCRAFT CONTROLS WITH MULTIDIMENSIONAL PI-REGULATOR

Mon, 30 Dec 2019 00:00:00 +0200

The article presents the synthesis of a functional diagram of an adaptive automatic control system (ACS) for controlling an aircraft with an automatically reconfigurable multidimensional PI controller, which provides the minimum static and minimum mean square error of control with minimal energy consumption for the formation of the control exposure. The synthesis of ACS algorithms is performed as a result of solving the problem of conditionally minimizing the quadratic functional of the generalized work (taking into account restrictions on state variables and control actions given by differential equations of the control object (CO) and inequalities). The mathematical description of the multidimensional CO is carried out using the CO model in the state space, which automatically takes into account the mutual influence of individual control loops on each other. As the state variables of the aircraft, linear displacements, speeds and accelerations of the center of mass of the aircraft, and angular displacements, speeds and accelerations of the rotational movement of the aircraft relative to the center of mass are used. The matrix equation of dynamics of the aircraft is formed by a system of nonlinear differential equations of the first order of forces and moments of forces acting on the aircraft. To ensure the minimum static control error, integrators are included in the ACS (for each control action). The algorithm for the formation of control actions of the extended CO, providing the declared properties of the ACS, is obtained as a result of solving the problem of conditional minimization of the generalized work functional. The task of conditional minimization of a functional with constraints is performed by the maximum principle. The resulting two-point boundary value problem is transformed by the invariant immersion method into a Cauchy problem for optimal values of state variables. The evaluation of the characteristics of a specific adaptive ACS for the spacecraft is expected to be obtained as a result of further research by mathematical modeling.

STUDY OF STRESS AND STRAIN STATES OF REINFORCEMENT IN RUBBER-METAL PRODUCTS DURING THEIR MANUFACTURE

Mikhail Stepanovich Khorolskyi, Anatoliy Fedorovich Sanin (Author) — Mon, 30 Dec 2019 00:00:00 +0200

Stress and strain states are typical for rubber-to-metal bonding areas in the rubber-metal products developed specifically for the space industry, particularly those with thin-walled reinforcement, i.e. dampers and brackets. To achieve maximum rubber adhesion to metal, 80-120 µm shot or aluminum oxide blasting at the air pressure of 0.6-0.8 MPa is applied to the reinforcing steel of straight or any other shape. The blasting process causes an improvement in the hardness of the material by strain hardening, which results in the backward deformation of the reinforcement. After the blasting process, the reinforcing steel changes its geometry and stress and strain state. A new equilibrium state appears.

Rubber-metal products are typically cast under pressure using press molds by vulcanizing a rubber mix at high temperatures. Bonding rubber to metal using an adhesive takes place simultaneously. During the molding process, the deformed reinforcement returns to its original shape once the pressure is applied and preserves its shape for some time due to strong rubber-to-metal bonds. Yet, after the rubber-metal product is taken out of the mold, the stress and strain state emerges in the rubber-to-metal bonding area, as the reinforcing steel wants to return to its equilibrium state. With the relaxation developing as time passes, delamination of the rubber-to-metal system occurs and the product can no longer be used.

As a result of our research, we determined the relationship between the strength of the rubber-to-metal adhesion and the deformation using standard samples and proposed the methods of the stress and strain state simulation that can be used for development of new technologies enabling manufacturing of rubber-metal products with no or small stress and strain levels. The paper outlines the key approaches to relieving the stress and strain states in the rubber-metal products with thin-walled reinforcement. Using the standard samples, we proved that relieving of the stress and strain state will ensure product operability during the entire period of warranty.

CONTROL WITH REDUCING OF DISTURBING FACTORS

Yuri Dmitrievich Sheptun, Sergey Viktorovich Spirkin (Author) — Mon, 30 Dec 2019 00:00:00 +0200

The structural and dynamic features of the space (moving outside the dense layers of the atmosphere) stages of rockets - carriers of spacecraft as control objects are analyzed. The reasons are investigated - disturbing factors that generate external forces and moments that determine the disturbed motion of space rocket stages. For space rocket stages, disturbing factors are: mass asymmetry of the stage relative to its longitudinal axis and angle of mismatch of the line of action of the thrust vector of the propulsion system of the stage with the longitudinal axis of the stage. It is shown that when using the stage control deviating in the hinge of the marching engine as the executive organs of the control system, the effect of auto-reduction of the mentioned disturbing factors arises. The consequence of the autocompensation of disturbing factors is the reduction of disturbing forces and moments that violate the programmed motion of the step in the pitch and yaw planes. Mass asymmetry and the angle of mismatch of the line of action of the thrust vector of its engine and the longitudinal axis of magnitude are constant. Therefore, a decrease in perturbing forces and moments is accompanied by a decrease in the amount of energy (fuel) spent on processing (zeroing) perturbations of the parameters of the perturbed motion of the stage. It is shown that if the thrust of a space-stage engine is 8000 kgf, the engine operating time (flight time of the stage) is 500 sec, the specific engine thrust is 330 sec, the mass asymmetry is 0.05 m, the angle of mismatch is 0.25 degrees, then fuel economy can reach 200 kgf. The studies were performed using mathematical modeling methods.

КОМПЕНСАЦІЯ ЛІНІЙНОГО ЗБУРЕННЯ СИСТЕМИ СТАБІЛІЗАЦІЇ РАКЕТИ

В. В. Авдєєв (Author) — Wed, 05 Sep 2018 00:00:00 +0300

For disturbed motion in one plane with taking in account the inertia of an executive device the connection between a law of control determined by method of modal control and error matrixes is established. The roots of characteristic polynomial are according to the Batterwort’s scheme on hemicycle of a given radius even distributed. The results can be used in system design as an alternative option of a law of control determination
based on the requirements for accuracy figures.

NUMERICAL SIMULATION OF SUBSONIC FLOW OVER A PROFILE

S. V. Alekseyenko (Author) — Wed, 05 Sep 2018 00:00:00 +0300

A methodology and software-methodical support for describing the processes of flow around a wing profile by a viscous compressible flow based on the Reynolds-averaged Navier – Stokes equations using the Spalart – Almaras turbulence model is developed. The effect of Mach number variation at constant Reynolds number on the profile performance coefficients is analyzed.

КРИЗИС ТЕПЛООТДАЧИ В ЖИДКОМЕТАЛЛИЧЕСКИХ ИСПАРИТЕЛЯХ С СОСТАВНОЙ КАПИЛЛЯРНО-ПОРИСТОЙ СТРУКТУРОЙ В ВЫХОДНОМ СЕЧЕНИИ

С. А. Белогуров (Author) — Wed, 05 Sep 2018 00:00:00 +0300

Results of experimental research represent conditions of heat transfer deterioration for boiling potassium in a straight-through evaporator with a composite capillary-porous structure in the output section. A region of mass velocities is identified, where boundary vapor content, with heat transfer deterioration in the composite capillary-porous structure, is higher than in smooth-tube evaporators and evaporators with a simple capillary structure.

ПОРОЖДАЮЩЕЕ ПРОЕКТИРОВАНИЕ – ИННОВАЦИОННЫЙ ПОДХОД К ПРОЕКТИРОВАНИЮ ЦИФРОВОГО ПРОТОТИПА ИЗДЕЛИЯ

Л. Н. Дейнеко, Н. Ф. Тертышная, А. В. Трубин (Author) — Wed, 05 Sep 2018 00:00:00 +0300

The problem of 3D-model weight optimization, which is used in a carrier rocket tank design, with use of technology of the generating design is considered. Tools and methodology of the generating design, with use of the Autodesk Inventor Professional software product are presented. The analysis of manufacturing techniques of the optimized details with technology of the generating design is carried out.

РЕСУРСОЗБЕРЕЖЕННЯ ЯК НАПРЯМОК ДІЯЛЬНОСТІ КАФЕДРИ БЕЗПЕКИ ЖИТТЄДІЯЛЬНОСТІ

О. В. Долженкова, О. В. Золотько (Author) — Wed, 05 Sep 2018 00:00:00 +0300

The directions of activity and the results of NDMMT on the resource saving problem are analyzed. Scientific developments of the laboratory were introduced into the production of materials for rocket and space technology and other industries.

ТЕРМОДЕФОРМАЦИОННЫЕ ПРОЦЕССЫ (УСАДКА) В МЕТАЛЛЕ ПРИ ПРОВЕДЕНИИ СВАРОЧНЫХ РАБОТ ПРИ ИЗГОТОВЛЕНИИ КОРПУСНЫХ ОТСЕКОВ

О. А. Дружинина, Е. С. Болюбаш (Author) — Wed, 05 Sep 2018 00:00:00 +0300

The questions of welding and deformation are considered the constructions, caused by internal transversal tensionsarising up in the weld-fabricated guy-sutures. The calculation of shrinkage of metal (АМг6) is conducted, the result of measuring over shrinkage is brought after welding, given to recommendation on reduction of welding deformations, tensions and moving, setting of technological allowances for the parry of influence of termal deformation processes.

НАУКОВА ШКОЛА З БАЛІСТИЧНОГО ПРОЕКТУВАННЯ ЛІТАЛЬНИХ АПАРАТІВ НА КАФЕДРІ ПРОЕКТУВАННЯ ТА КОНСТРУКЦІЙ І В НДЛ РАКЕТНО-КОСМІЧНОЇ ТЕХНІКИ НДІ ЕНЕРГЕТИКИ: ІСТОРІЯ ТА СЬОГОДЕННЯ

Л. Г. Дубовик (Author) — Wed, 05 Sep 2018 00:00:00 +0300

The history of creation and the present one of scientific directions of chair of designing and designs and research laboratory of rocket-technical engineering of scientific research institute of power, introduction of results in practice are considered. The powerful contribution to development of this direction of professor Dronja Nikolay Mihajlovicha is noted.

МОДЕЛИРОВАНИЕ ТЕЧЕНИЯ ГАЗА В КАМЕРЕ ЖРД С УЧЕТОМ ЕЕ ОХЛАЖДЕНИЯ

И. Д. Дубровский, В. Л. Бучарский (Author) — Wed, 05 Sep 2018 00:00:00 +0300

The problem of one-dimensional motion of gas in thecombustion chamber of the liquid rocket engine, taking into account its heat exchange with the chamber wall and with the cooling liquid, is considered in the article. The results of calculating the cooling of the chamber obtained by numerically solving the system of differential equations of gas dynamics combined with the heat balance equation are presented. The analysis of the results allows to assert about the possibility of applying the proposed method in practice.

ПЕРСПЕКТИВНІ НАПРЯМКИ НАУКОВИХ ДОСЛІДЖЕНЬ НА КАФЕДРІ ДВИГУНОБУДУВАННЯ

Wed, 05 Sep 2018 00:00:00 +0300

A retrospective of directions of scientific researches of employees of the chair of engine-building of physical-technical faculty is presented. The historical formation and development, achievements of the faculty's scientists in the field of rocket engine construction, as well as prospects or their further research are considered.

РАЗРАБОТКА И ИССЛЕДОВАНИЕ МЕТОДОВ НЕЙТРАЛИЗАЦИИ СОРБЕНТА, ЗАГРЯЗНЕННОГО ПАРАМИ КОМПОНЕНТОВ РАКЕТНОГО ТОПЛИВА

С. А. Кудринский, Г. Л. Поздеев, Л. В. Муравлева, Т. В. Гуназа (Author) — Wed, 05 Sep 2018 00:00:00 +0300

The paper discusses the issues for neutralization of solid waste – sorbent saturated with vapors of highboiling propellants (dinitrogen tetraoxide – oxidizer, nonsymmetrical dymethylhydrazine – fuel). The original methods of neutralizing the sorbent, contaminated with vapors of propellants, have been developed and the known methods have been experimentally checked. The neutralization methods bench test results have been presented.

ЭКСПЕРИМЕНТАЛЬНЫЕ ИССЛЕДОВАНИЯ СВОЙСТВ УГЛЕРОДНЫХ КОМПОЗИЦИОННЫХ МАТЕРИАЛОВ НА ТРУБЧАТЫХ МОДЕЛЯХ

Wed, 05 Sep 2018 00:00:00 +0300

At present, carbon composite materials are widely used in space technology. The tendency to expand the consumption of carbon fiber in the manufacture of parts and structures requires the study of new ways of obtaining it. A method of modifying carbon fibers by atmospheric plasma treatment in two different media was used: acrylic acid and allylamine, and fillers were studied on tubular models. As a result of the tests, it was found that atmospheric plasma treatment in acrylic acid environment, contributes to the improvement of the characteristics of CFRP by ~ 25 % more efficiently than processing in allylamine for the types of fillers studied.

РЕЗУЛЬТАТЫ ИССЛЕДОВАНИЯ ВНУТРЕННИХ ТЕПЛОЗАЩИТНЫХ ПОКРЫТИЙ ИЗДЕЛИЙ РАКЕТНО-КОСМИЧЕСКОЙ ТЕХНИКИ

Т. А. Манько , К. В. Козис (Author) — Wed, 05 Sep 2018 00:00:00 +0300

The article presents the main results of works related to material creation and study, and development of manufacturing of inter heat-protection cover made of composite materials in Yuzhnoye SDO for solid propellant rocket engines.

ДОСЛІДЖЕННЯ ПОЛЯРИЗАЦІЙНОЇ СКЛАДОВОЇ СТРАТОСФЕРНОГО ШАРУ ЗЕМЛІ ЗА ДОПОМОГОЮ УЛЬТРАФІОЛЕТОВОГО ПОЛЯРИМЕТРА

Wed, 05 Sep 2018 00:00:00 +0300

The article is devoted to the study of the actual issue of the polarization component of the stratospheric layer of the Earth with the help of an ultraviolet polarimeter. This problem is little studied and needs further study. The paper presents the structural and functional diagrams of the device. Considerable attention is paid to the energy calculation for the optical part of the device.

ЧИСЛЕННОЕ МОДЕЛИРОВАНИЕ ВЗАИМОДЕЙСТВИЯ НЕДОРАСШИРЕННОЙ СВЕРХЗВУКОВОЙ СТРУИ ГАЗА С ПЛОСКОЙ ПРЕГРАДОЙ

С.А. Николин, А.А. Приходько (Author) — Wed, 05 Sep 2018 00:00:00 +0300

The results of numerical modeling based on the nonstationary Reynolds-averaged Navier – Stokes equations for the interaction of an underexpanded supersonic gas jet with a flat obstacle, which was established at different distances from the nozzle exit section are presented. The results of the calculations are presented in the form of the distribution of the Mach number and the density gradient in the calculated region, and the pressure and friction coefficients over the surface of the plate. The results of the numerical calculation are compared with the experimental data.

РАЦИОНАЛЬНАЯ ТЕХНОЛОГИЯ УТИЛИЗАЦИИ ТЕПЛОТЫ ТУРБОКОМПРЕССОРНЫХ СТАНЦИЙ

Г. С. Олишевский, И. Г. Олишевский (Author) — Wed, 05 Sep 2018 00:00:00 +0300

Analytical analysis of various technologies for heat recovery of turbocharger stations and justified their choice of the most rational options and values of intermediate temperatures of water heating between air coolers of a turbocharger.

ИСПОЛЬЗОВАНИЕ ЧИСЛЕННОГО МОДЕЛИРОВАНИЯ ПРИ РАСЧЕТЕ ОСТАТКОВ КОМПОНЕНТОВ ТОПЛИВА

И.Н. Орлянская, О.М. Иванов (Author) — Wed, 05 Sep 2018 00:00:00 +0300

Analysis comparison of the results of the determination of the propellant residual in the propellant supply system by two methods: experimental and numerical was spent. Experimentally, the propellant residual was determined by the scale model. The propellant residual was determined numerically using ANSYS (CFX) software. Recommendations are given for setting up the software product to obtain satisfactory convergence with experimental data.

ЭКСПЕРИМЕНТАЛЬНОЕ ОПРЕДЕЛЕНИЕ КАПИЛЛЯРНОГО РАДИУСА ЯЧЕЕК СЕТОК С ДЕФОРМИРОВАННОЙ СТРУКТУРОЙ ПЛЕТЕНИЯ

Н.О. Позднышев (Author) — Wed, 05 Sep 2018 00:00:00 +0300

The article is devoted to the experimental study of the change in the capillary radius of cells of metal woven nets, depending on the degree of deformation of the structure of their weaving. The values of the measurements of the capillary radius of the cells are given as a function of the interlacing angle of the fibers of the nets. Recommendations are given on the possibility of using deformed nets in devices to ensure the continuity of the components of the fuel tanks of spacecraft.

ИСПЫТАНИЕ СОПЛОВОЙ МЕМБРАНЫ МИКРОГАБАРИТНЫХ РДТТ И ЧИСЛЕННОЕ МОДЕЛИРОВАНИЕ ЕЕ ЭКСПЛУАТАЦИОННОГО СОСТОЯНИЯ

Ю.С. Прокофьев, В.В. Сатокин, Ю.Н. Бабей (Author) — Wed, 05 Sep 2018 00:00:00 +0300

The problem conducting field tests nozzle membrane of micro size RESF, analysis results and carrying out numerical modeling of operational state virtual copy real membrane is considered.

ОПРЕДЕЛЕНИЕ ХАРАКТЕРИСТИК ХИМИЧЕСКИХ ИСТОЧНИКОВ ТОКА С ЦЕЛЬЮ ПОДТВЕРЖДЕНИЯ ВОЗМОЖНОСТИ ИХ ИСПОЛЬЗОВАНИЯ В СОСТАВЕ СИСТЕМ ЭЛЕКТРОСНАБЖЕНИЯ

В.А. Пырец, В.С. Рева, К.Н. Земляной, О.В. Гаврилов, К.В. Безручко (Author) — Wed, 05 Sep 2018 00:00:00 +0300

In the article the question definitions of the guaranteed residual service life of the storage battery, which allows you to accurately determine the parameters and characteristics, and also to predict them in the course of its life cycle. One of the methods of confirming the operability of chemical current sources and determining their further failure-free operation is considered, which are accelerated climatic tests. Also shown is the discharge capacity of chemical sources of current in the form of mathematical models, what makes it possible to determine the characteristics of chemical sources of current under normal conditions, and vice versa, when the capacitance is known from measurements of accelerated climatic tests.

ОПРЕДЕЛЕНИЕ ДЕФОРМИРОВАНИЯ ИСХОДНОГО ПРЯМОУГОЛЬНОГО СЕЧЕНИЯ ПРОФИЛЬНЫХ ЗАГОТОВОК ПРИ ИЗГОТОВЛЕНИИ ГИБКОЙ ЭЛЕМЕНТОВ КОНСТРУКЦИЙ ИЗДЕЛИЙ АЭРОКОСМИЧЕСКОЙ ТЕХНИКИ ТИПА ШПАНГОУТ

Е.Г. Седачова, А.В. Кулик, Н.Н. Убизький (Author) — Wed, 05 Sep 2018 00:00:00 +0300

The worked out mathematical model is for determination of deformation of the rectangular crossing of purveyances at bending.

ЭКСПЕРИМЕНТАЛЬНОЕ ПОДТВЕРЖДЕНИЕ РАБОТОСПОСОБНОСТИ КАПИЛЛЯРНОГО ЗАБОРНОГО УСТРОЙСТВА (СЕТЧАТОГО РАЗДЕЛИТЕЛЯ) ПРИ ПРОГРАММНОМ РАЗВОРОТЕ

И.В. Седых, Д.Э. Смоленский, Д.С. Назаренко (Author) — Wed, 05 Sep 2018 00:00:00 +0300

One of the problems of providing a group launch of spacecraft is to ensure the re-launch of the propulsion engine for the transition to another orbit, after the separation of the first vehicle. When the spacecraft is separated into a stage, an acceleration is applied directed toward the bottom of the tank and leading to an outflow of the fuel component from the mesh separator. This, in turn, leads to the denudation of the mesh separator and the penetration of gas under it, which can lead to a breakdown of the launch of the engine. In view
of the complexity of the hydrodynamic processes taking place in the tanks, experimental confirmation of the mesh separators chosen during the design is required.
In this paper, we describe the methods for determining the model conditions (the choice of the scale of the experimental design, the type of the model fluid, the magnitude of the accelerations, etc.), a description of the stand designed specifically for the test data, and the results of the experimental confirmation of the capillary sampling device performance in the separation of the spacecraft. The results of the performed works confirm the correctness of the decisions made in the development of capillary sampling devices.

ПРОЦЕС СТРУКТУРУВАННЯ ЕПОКСІУРЕТАНОВОГО КАУЧУКУ ПІД ДІЄЮ ДИГІДРАЗОНУ ДІАЦЕТИЛФЕРОЦЕНУ

Т.Ю. Смольникова, О.Ю. Нестерова, В.Д. Гулик (Author) — Wed, 05 Sep 2018 00:00:00 +0300

The process of structuring of oligomericepoxyurethane rubber with terminal epoxy groups under the action of dihydrazone 1,1 'diacetylferocene under conditions of prolonged heating was studied. The crosslinking process proceeds with the formation of a rubber-like elastic polymer with a structure of a rare-mesh net. The structure of the synthesized dihydrazone 1,1'-diacetylferocene was proved on the basis of NMR1H and chromatomass-spectroscopy data.

ДВУХУРОВНЕВАЯ ОПТИМИЗАЦИЯ ПРОГРАММНОГО КОДА ДЛЯ ПОЛИНОМОВ ЛЕЖАНДРА ВЫСОКИХ ПОРЯДКОВ

В. И. Усиченко, Д. В. Заврайский (Author) — Wed, 05 Sep 2018 00:00:00 +0300

The expediency of two-level optimisation of a program code for calculation Legendre polinomials of high orders is shown. The conclusion about efficacy of optimisation is made on the basis of timekeeping by operating system means. This paper is a second part of article [8].

ОСОБЕННОСТИ ДИНАМИКИ ВОЗВРАЩАЕМОЙ ЧАСТИ ПЕРВОЙ СТУПЕНИ САМОЛЕТНОЙ СХЕМЫ С ТУРБОРЕАКТИВНЫМ ДВИГАТЕЛЕМ

В.И. Усиченко (Author) — Wed, 05 Sep 2018 00:00:00 +0300

The returned part of the first stage of plane type with a turbojet has some dynamic features. The main things from these features are reflected in this article. Possibility of reception of the landing characteristics close to the plane is estimated also.

КОМБІНОВАНЕ КЕРУВАННЯ КОСМІЧНИМ СТУПЕНЕМ РАКЕТИ-НОСІЯ

Ю. Д. Шептун (Author) — Wed, 05 Sep 2018 00:00:00 +0300

The processes of working out the perturbations of the movement parameters of the LV stages are characterized by features that are not currently taken into account in the algorithms for zeroing perturbations by missile control systems. The article contains proposals on minimization of fuel consumption for zeroing the perturbations of rocket motion parameters.

НАУКОВІ ДОСЯГНЕННЯ КАФЕДРИ БЕЗПЕКИ ЖИТТЄДІЯЛЬНОСТІ

А. Г. Шишацький, Ю. М. Мелікаєв, Ю. В. Тарасенко (Author) — Wed, 05 Sep 2018 00:00:00 +0300

The presented results of theoretical and experimental studies of the Department of Safety of Life Activities on improving working conditions and safety at work.