 Subjects -> AERONAUTICS AND SPACE FLIGHT (Total: 124 journals)
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- Decision support modeling in the procedure of increasing load capacity and
flight efficiency of transport category aircraft modifications
Authors: Liudmyla Kapitanova, Viktor Riabkov, Andriy Koryagin
Pages: 4 - 13
Abstract: Enhancing flight efficiency is a pressing issue in the development of the aircraft manufacturing industry. Aircraft manufacturers in Europe, the USA, China, and Ukraine are following this path of improvement for such aircraft, as it is the most economically efficient approach. This method significantly reduces the time required for design, prototype production, flight testing, and the start of operation of the first units. At the National Aerospace University "KhAI", the Department of Aircraft and Helicopter Design has established a school focused on implementing necessary modification changes in transport category aircraft. The distinctive feature of this approach is that only outdated parameters of a well-proven baseline aircraft are modified, while the majority of the parameters are carried over to the modification from the original version. This foundation underpins the research presented in this publication. The research aims to develop parametric models to support decision-making during the preliminary design stage for enhancing the load capacity and flight efficiency of transport category aircraft modifications. Research methods: a method of changes assessing in wing induced drag with modifications in its planform shape; a method of "payload-range" characteristics creation. The object of the research is the development of parametric models to support decision-making during the preliminary design stage of transport category aircraft modifications. The following results were obtained a package of models was developed, including: ensuring the specified load capacity and "payload-range" characteristics; a temporal model of parameter changes in modifications considering the time frame for modifications; cost indicators for changes at individual stages and throughout the entire life cycle; representation of modifications in terms of their competitiveness; formation of wing geometric shapes with minimal induced drag at a given lift; ensuring that the takeoff and landing characteristics of modifications remain at the level of the baseline aircraft; coordination of wing lift coefficients and engine throttle characteristics to ensure minimum fuel consumption in cruise flight mode. Each model serves as a tool to address the main tasks of increasing load capacity and the range of useful payload transport at the moment of modification introduction and throughout its entire life cycle. Examples of real modification changes in domestic transport aircraft, such as the An-32, An-32B, and An-132U, demonstrate that using the proposed decision support models during the preliminary design stage has ensured their competitiveness throughout their operational life. Practical significance of the obtained results: Based on the developed models, the load capacity and flight efficiency of modifications like the An-32 and An-32B have been increased, and the parameters of the An-132U modification with Motor Sich engines have been optimized, surpassing the load capacity and flight efficiency of all other analogs of light military transport aircraft. Scientific novelty of the obtained results: For the first time, a method was developed to minimize induced drag during cruise flight with the required lift force, i.e., for a given load, allowing an increase in the range of modified aircraft.
PubDate: 2025-01-23
DOI: 10.32620/aktt.2025.1.01
- Experimental investigation of the performance of a loop heat pipe-based
cooling system under ultra-high dypass ratio turbojet engine conditions
Authors: Pavlo Gakal, Igor Rybalchenko, Oleksii Tretyak, Viacheslav Nazarenko
Pages: 14 - 27
Abstract: The subject of this article is the heat transfer processes in a loop heat pipe (LHP) to solve the problem of maintaining the temperature regime of the valves of the air-bleeding system of an aircraft engine. The goal was to experimentally substantiate the operability and efficiency of a cooling system based on LHP for the temperature conditions of a perspective aircraft engine with an ultra-high bypass ratio. The task to be solved: to create a test bench for studying heat transfer processes in cooling systems based on LHP. The test bench should reproduce the temperature of the aircraft engine and the orientation of the LHP in the gravitational field. To investigate the operability of the cooling system under different heat loads, heat sink temperatures, orientation in the gravitational field, and additional thermal insulation. The methods used are: experimental approach, test planning, and statistical methods for processing experimental results. The following results were obtained. A test bench was created to investigate the heat transfer processes in a cooling system based on LHP. Toluene is used as a LHP’s coolant. The temperature conditions of the perspective aircraft engine were considered when creating the test bench. The performance of the cooling system was studied under different orientations of the gravitational field, heat sink temperature, and heat load. The obtained experimental results allowed us to analyze the influence of the orientation in the gravitational field, heat sink temperature, and additional vacuum thermal insulation of the evaporator and liquid line on the LHP performance and efficiency. Conclusions. The novelty of the results obtained is as follows: for the first time, the possibility of using a cooling system based on the LHP in temperature conditions of the perspective aircraft engine with an ultra-high bypass ratio was experimentally approved; it was proven that the LHP with toluene as part of the cooling system can effectively operate stably, without pulsations and without overheating of the cooled devices under different heat loads, heat sink temperatures, and orientation in the gravitational field.
PubDate: 2025-01-23
DOI: 10.32620/aktt.2025.1.02
- Compromise kinetic-fluid model of electrons dynamics in electric
propulsion devices with closed electrons drift as an alternative to the
hybrid PIC-Fluid method
Authors: Serhii Nesterenko, Huang Zhihao, Shahram Roshanpour
Pages: 28 - 37
Abstract: Electric propulsion devices with closed electron drift include Hall effect thrusters, plasma-ion thrusters with a radial magnetic field, and helicon thrusters, which are sources of plasma, ions, and electrons. Within the framework of the hybrid PIC-Fluid method for calculating a Hall effect thruster, which has been actively replicated in recent decades, the level of detail in the PIC unit does not correspond to the criterion of substance continuity, and the fragmentary set of equations in the Fluid unit does not contain several terms necessary for the calculation and indicates a profound misunderstanding of the origin and limits of applicability of the equations and the true nature of the processes. The calculation of ionization characteristics, the height of the potential barrier at the plasma boundary, the electrons and ions, and their energy fluxes to the surface of the thruster chamber is carried out using a Maxwell distribution, the conditions for the formation of which did not correspond to the realities in the rarefied plasma of electric propulsion devices. The closeness of the calculated integral characteristics to the measured ones is achieved using empirical coefficients with a difference of tens of times in different publications with a complete inability to predict the characteristics of samples of electric propulsion devices that have not yet been developed and tested. In this paper, a compromise method is proposed, the possibility of which is due to the closeness of the electron velocity distribution to isotropic due to the influence of a strong magnetic field and non-specular reflection of electrons from the potential barrier at the plasma boundary. The method operates with the angular moments of the distribution function without integrating the components of the kinetic equation by the velocity module. To calculate the densities of mass, momentum, energy, and their fluxes considering dissipative processes, it is sufficient to determine the angular moments of the second and third orders, the traces of which include the moments of the zero and first orders, respectively. Equations of angular moments are given as intermediates between the kinetic equation and the velocity distribution function moments equations. The expansion of the velocity distribution function in a series of angular moments is recorded. Calculations have been performed that show sufficient agreement with the known measurement results and a significant difference in the characteristics of the Langmuir layer and plasma at the boundary with it from those found using the Maxwell distribution. The use of the obtained results allows us to significantly increase the accuracy of predicting the thruster parameters and thereby reduce the volume of costly experiments to optimize their characteristics.
PubDate: 2025-01-23
DOI: 10.32620/aktt.2025.1.03
- Development experience of the centripetal turbine flow part for an
aviation engine air starter
Authors: Roman Rusanov, Igor Kravchenko, Andrii Rusanov, Sergiy Riznyk, Yurii Kukhtin, Marin Chugay, Mykhailo Sukhanov
Pages: 38 - 49
Abstract: The subject of this paper is to study the approaches for the flow part design of a centrifugal turbine stage, which are considered on the example of an air starter with a capacity of 150 kW. The goal is to develop the spatial shape of the centripetal turbine flow part of the air starter of an aircraft engine. The tasks were as follows: determine the full 3D shape of the centripetal turbine of the air starter of an aircraft engine, sufficient for the development of design documentation, and calculate the gas-dynamic characteristics of the turbine, including the self-braking frequency. The research was carried out using modern numerical calculation methods and the design of radial-axial centrifugal turbomachine flow parts, implemented as a software complex IPMFlow. The following results were obtained. Two versions of the flow part have been developed: with profiled and thin rotor blades. The first version with profiled blades has better gas-dynamic characteristics, as well as reserves for further improvement, but it does not meet the requirements for strength. To eliminate the mentioned shortcomings of the first version, the method of blade profiling of radial-axial flow parts was improved, and with its help, a second version of the flow part with a rotor with thin blades, which has better characteristics in terms of strength and acceptable weight, was developed. This version was adopted as the basis for further design and production. Conclusions. The scientific novelty of the obtained results lies in the improvement of the method of radial-axial flow-part blade profiling. The proposed method provides such a shape of the blades that in a plane perpendicular to the rotor rotation axis, the blade centerline coincides with the radial line. In this case, the possibilities of so-called "spatial profiling" are reduced, in particular, the compound offset (saber-like) of the blades. This approach makes it possible to significantly reduce the load and stress under the action of centripetal forces. With the help of improved methods, a version of the flow part with a rotor and thin blades was developed. Although the efficiency of the turbine was slightly lower than that of the first version, it is quite high, and the power is more than the design value.
PubDate: 2025-01-23
DOI: 10.32620/aktt.2025.1.04
- Research on the method of gear control using a coordinate measuring
machine
Authors: Valeriy Sikulskiy, Kateryna Maiorova, Sergiy Zaklinskyy, Artem Suslov
Pages: 50 - 58
Abstract: The subject of study in this article is the approbation of theoretical and technical solutions for the use of coordinate-measuring machines (CMM) in the implementation of technical inspections of the parameters of high-precision gear-type parts. The purpose of the article is to study the systematic errors in the geometric accuracy of the gear wheel surfaces and edges by the contact measurement method using the chosen CMM. Methods of research are empirical – analysis of existing and widespread methods of measurement, full-scale experiments, and inspection. The research tasks are to measure the gear wheel involute (profile) and the lateral line (direction) of contact, pitch errors (separately) on the left and right sides of the gear teeth, gear ring runout, and to determine the influence of eccentricity on pitch and runout errors. Additionally, the study aims to check the studied gear wheel for compliance with the 7th degree of accuracy according to DSTU ISO 1328-1:2006. The methods used are: empirical and theoretical methods of measurement, comparison, and analysis. The results of the study presented in the article: indicate that the length of the studied gear common normal has a critical accuracy, which is about 99% of the tolerance for this parameter. Therefore in practice, to check the quality of manufacturing of the teeth surfaces of the involute cylindrical gears, it is necessary to use the contact measurement method, which involves the direct contact of the sensitive element (probe) with the surface of the examined object, as it provides accuracy up to 1,5mm, which in turn, minimizes the risks of part rejection as spoilage. Conclusions: According to the technical inspection data, it was determined that the critical systematic error is affected by the total accumulated error of the tooth pitch, which is 55.3% of the tolerance, as well as the radial runout of the working surfaces, which is 54.8% of the tolerance. It should be noted that other parameters maintain a margin of accuracy of 20-30%. This can be attributed to the degree of compliance with the manufacturing technology of the experimental gear sample. The following research may involve post-operational inspection at each step of gear manufacturing in order to determine the critical stages of the technology where the length of the gear common normal acquires a critically acceptable accuracy. Furthermore, the subject of further research is the creation of a methodology for the combined use of optical 3D scanning and the contact measurement method in order to enhance measurement accuracy while reducing time and scope of measurements.
PubDate: 2025-01-23
DOI: 10.32620/aktt.2025.1.05
- Gamification in studying celestial mechanics using Kerbal Space Program
Authors: Pavlo Ponomarenko
Pages: 59 - 69
Abstract: The rapid development of technologies and their implementation in the educational process provide an opportunity to apply gamification, that is, the use of game mechanics and elements for in-depth study of a complex technical discipline. Computer games such as Kerbal Space Program (KSP) have already created an environment where students can comprehend and practically apply the theory of space mechanics with a sense of challenge and reward. The use of gamification in the learning process has many advantages: improving academic performance, developing interaction between students, and increasing interest in technical sciences. The subject of this study is the capabilities and processes of the KSP game. The object of this research is the process and means of gamification in the study of celestial mechanics. The aim of this work is to study the possibilities, limitations, and prospects of using Kerbal Space Program in the gamification of the study of the basic concepts of celestial mechanics. The implementation of the stated research goal involves solving the following tasks: analyzing the ability of KSP to implement certain celestial mechanics; studying the prospects of KSP in teaching the basic concepts of celestial mechanics through game mechanics; study of the correspondence of the game physical model to real physical processes; and identification of limitations and prospects for the use of gamification through KSP for educational purposes. This study used the system analysis method of computer gamification tools. The following results were obtained in the course of the study: during the comprehensive analysis of KSP, it was established that the game complies with the basic laws of celestial mechanics and is capable of fairly accurately modeling orbital motion, maneuvers, gravitational phenomena, etc.; the main limitations and prospects for the use of KSP in the educational process were outlined. Conclusions: the study demonstrates that KSP implements the basic principles of celestial mechanics and provides tools for the practical mastery of complex concepts by students. This study shows the significant potential of the game, which allows significantly expanding educational opportunities in the study of celestial mechanics, and the interactive format of the game allows students to learn complex physical phenomena and concepts in an accessible and visual way.
PubDate: 2025-01-23
DOI: 10.32620/aktt.2025.1.06
- Modeling the diversification of a high-tech enterprise through relocation
and supplier recovery
Authors: Oleg Fedorovych, Liudmyla Lutai, Andriy Rybka, Yevhenii Polishchuk, Volodymyr Solovyov, Valeriy Fedorovych
Pages: 70 - 80
Abstract: This study addresses the urgent challenge of enterprise diversification to restore high-tech production (aviation technology, UAVs, rocket engineering, etc.) through relocation and modification of component suppliers. The research is particularly relevant for high-tech enterprise recovery during national emergencies and post war reconstruction. Therefore, the topic of the proposed publication, which examines the activities necessary for planning projects related to the diversification of enterprises under threats, is relevant. This study proposes a comprehensive set of mathematical, simulation and agent-based models to facilitate planning for diversification and supply recovery under emergency conditions. This study analyzes existing challenges in enterprise diversification, focusing on relocation due to various threats, including military threats. A systematic analysis of the diversification logistics of high-tech enterprises is conducted. A set of diversification strategies is developed with a special focus on enterprise relocation and supplier recovery. Potential new locations for enterprise relocation are analyzed based on qualitative assessments of key logistical indicators (e.g., safety, infrastructure, and supplier proximity). A set of alternative relocation sites is established, and the most suitable location is selected using lexicographic ordering. The study also focuses on forming a network of component suppliers to consider enterprise relocation and emerging orders, including military applications. The supplier selection and supply routes are optimized using integer (Boolean) programming, accounting for key logistical factors such as component inventory levels, delivery time, costs, and supply risks. To analyze the dynamic process of transporting technological equipment and components, a simulation model was developed using the AnyLogic agent-based platform. A set of agents is formed that represents the main logistical events for planning the enterprise relocation. Based on the simulation results, key relocation indicators are assessed, including location selection, supplier network formation, supply route optimization, delivery time, and inventory levels. The scientific novelty of this research lies in the development of original models that determine a new location for high-tech enterprises, form a network of suppliers to meet production needs, establish supply routes and evaluate feasibility and risks in executing a diversification plan under special conditions. These findings are highly relevant for planning diversification processes in high-tech production, justifying enterprise relocation decisions, approving supplier networks and forming rational and secure supply routes under threat conditions. These efforts ensure the effective recovery of high-tech production during national emergencies and post war reconstruction.
PubDate: 2025-01-23
DOI: 10.32620/aktt.2025.1.07
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