Авиационная и ракетно-космическая техника. Рубрика в журнале - Сибирский аэрокосмический журнал
The assessment of high pressure pipelines of thermal power stations by non-destructive methods
Статья обзорная
The method of the monitoring of the thermal stations high pressure pipeline is described.
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The definite questions of simulation of transformable space structures dynamics
Статья научная
This paper describes large transformable space structures with various configuration in the folded transport posi- tion and in the open working one. As an example, simulation of transformable space structures dynamics is shown for the antenna circuit foldable load-bearing frame with diameter of 5 m. For investigation of the foldable frame deploy- ment dynamics, a design scheme presented by a system of rigid bodies connected with each other by hinges is accepted as it is simple, but at the same time it considers features of the structure well enough. For performing stress analysis of the foldable frame elements during deployment, the frame shape at the certain time point of deployment, when relative velocities of adjacent elements are ultimate, is chosen. As a results of calculation using MSC.Adams software, positions, velocities and accelerations of the centres of mass of the foldable frame elements as well as the angular velocities and accelerations of the elements for each time step of the deployment are obtained. To perform stress analysis of the fold- able load-bearing frame, finite element model of the frame is developed using MSC.Patran/Nastran software. As a re- sults of investigation of stressed and deformed states of antenna circuit foldable frame elements both without taking into account damping and with consideration of damping, stresses arising in the foldable frame elements at the certain time points during deployment are found.
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Статья научная
The analysis of conditions to provide durability, reliability and the transports effectiveness of the civil aircrafts is performed.
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Статья научная
The influence of the conditions for passing GLONASS and GPS satellite radio navigation signals on the errors of defining relative coordinates is studied.
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Статья научная
At present to transfer a spacecraft from a low earth to geostationary orbits propulsion systems of two types are most widely used: chemical and electric. Each type has its advantages and disadvantages. The application of any one of them does not always satisfy conflicting requirements. A possible solution may be the use of a combined propulsion system consisting of a chemical and electric propulsion system. This combination allows the spacecraft to be launched faster than using only electric motors, and it is more efficient in terms of the payload mass than using only a chemical propul- sion system. Electric propulsion engines (plasma or ionic) need energy sources. Usually, solar batteries are used for these purposes. The idea of using such a combined propulsion system, consisting of a solar electric propulsion sys- tem and the Fregat upper stage, was considered within the “Dvina TM” research project. The use of such a propulsion system requires, even at the design stage, to determine the parameters of the various types of engines that make up its structure. For a reasonable choice it is necessary to have information about the influence of the various propulsion system parameters on the final characteristics of the maneuver. When putting a spacecraft into orbit, it is necessary for the spacecraft to overcome Van Allen belts while the ele- ments of its design are subjected to intensive action of charged particles, which can significantly limit the period of ac- tive existence. Using a combined propulsion system, it is possible to shorten the time of being in a field of high radiation level significantly. The aim of the study was to synthesize a method for estimating the effect of the combined propulsion system parame- ters on the integral dose of radiation accumulated during the maneuver, when putting a spacecraft into a geostationary orbit. Different variations of the combined propulsion system application (thrust variations) allow to optimize the maneuver of the spacecraft and to reduce the integral dose of radiation. As a result of the work, a method was proposed to evaluate the influence of the parameters of the combined propul- sion system taking into account the passage of the Earth radiation belts, the program was implemented, calculations were made and the results were analyzed.
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The method of automated development of an assembly drawing of a cable network
Статья научная
The final stage of designing a cable network of spacecraft (as well as any other product) is the release of design and operational documentation. The automation of this process allows to improve the quality of documentation and de- crease the manufacturing time of spacecraft. The JSC ”Information Satellite Systems” (ISS) uses its own integrated software complex ”ALCAB” for releasing design documentation package for a cable network. For the assembly drawing development, the company uses CAD without integration with ”ALCAB”. In this regard, adding or removing items in the specification leads to the further refinement of the drawing. We propose the technique of solving a problem connected to the automation of the assembly drawing development for a cable network produced on a plane. The main task is to create associative link between the specification items and the cable network drawing. In this article we present the results of the analysis of the structure of the cable network 3D model designed in ”CATIA V5” CAD. There are schematic examples of harness topologies. The analysis identified the list of data to be extracted from the 3D model. We described the most interesting tools of ”CATIA V5” CAD that allow you to automate many processes including the development of your own software solutions. The analysis identified the tools for automated uploading of all re- quired data from the model. The examples of these tools are ”Knowledge Expert” and external programming environ- ment ”CAA RADE”. The analysis of their performance showed that the extraction of data using an algorithm developed with ”CAA RADE” was faster than using ”Knowledge Expert”. We described the potential of drawing tools in ”CATIA V5” CAD such as ”Electrical Harness Flattening” and ”Drafting” that allow you to automate the assembly drawing development. The paper proposes the method of automating he assembly drawing development of a cable network developed with the use of three-dimensional technology using the tools of ”CATIA V5” CAD and software designed at the JSC ”ISS”.
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Статья научная
A method of synthesizing a digital controller for a solar energy conversion channel in a power supply system of a spacecraft is presented. The method is based on the initial functional diagram of the pulse converter and the method of switching discontinuous functions. In accordance with the technique, which is formally presented in the form of eight consecutively executed items, a block diagram of the shunt converter has been developed in the basis of switching func- tions, which is taken as an example for testing the technique. The shunt converter is one of the three energy conversion channels in modern power supply systems of a spacecraft. The block diagram showed that all nonlinearity of the system can be reduced to nonlinearities of two multiplication links and nonlinearity of a pulse-width modulator. The possibility and acceptability of joint linearization of each of the specified nonlinear multipliers with a pulse-width modulator at the selected operating point is shown. A linearized block diagram of the control object was obtained, after which the trans- formation and simplification of the block diagram to a convenient form for calculation was carried out. Using the trans- fer functions of the linearized block diagram, the logarithmic frequency characteristics were calculated analytically and the results of their comparison with the frequency characteristics obtained experimentally on a simulation model, which confirmed their identity in the working frequency domain, were presented. At the same time, the specified simulation model of a shunt pulse converter, built in the Simulink package of the Matlab design environment, took into account all the mentioned nonlinearities of the real converter. According to the obtained logarithmic characteristics, a classical synthesis of the analogue prototype correcting section was produced. The transition from the analog correcting section of the prototype to the implementation of the digital correcting section is shown. Simulation modeling of a closed-loop power supply system with a synthesized analog controller, in its mode of operation from a solar battery, confirmed the correctness of the methodology and the achievement of the goals. The results of the work are intended to create a new onboard energy conversion equipment for power supply systems of high-potential spacecrafts. The scope of application of the project results is space instrumentation.
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The method of the disk friction determining of low mass flow centrifugal pumps
Статья научная
Low mass flow centrifugal pumps are currently widely used in the energy supply system of liquid rocket engines, the engines of correction, docks, consisting of on-Board power sources on-Board sources power supply system of fuel components in the in gas generator systems for inflating fuel tanks, and in temperature control systems of aircraft and spacecraft. When designing low mass flow centrifugal pumps for aerospace purposes, methods for calculating and optimizing the flow rate are often used corresponding to the design methods of full-size centrifugal pumps, which limits the mode and design potential of pumps and affects their energy characteristics and reliability. Reliability requirements often lead to the need to reserve units and fuel-supply systems. Despite the large amount of research works, the issues of reliable design of low mass flow centrifugal pumps with high energy and operational parameters for spacecraft and aircraft remains an urgent task. The article analyses the operational parameters of low mass flow centrifugal pumps used in aircraft and spacecraft power systems. Taking into account working fluid used and the temperature range, it was found that a laminar rotational flow with Reynolds number characteristic Re = 103 ¸ 3×105 is realized in the lateral cavity between the impeller and the pump housing. The determination of power losses on disk friction of the impeller technique is developed taking into account design features and the applied schemes. Equations for determining the disk friction coefficients are consistent with the dependencies obtained by other authors. The obtained equations for the laminar rotational flow made it possible to determine the dependences for the resistance moment and the disk friction power of the impeller determining of a low mass flow centrifugal pump.
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Статья научная
A generalized analysis of a high frequency key generator is conducted. This analysis allows the power indicators estimation of the generator in a wide frequency range, and in scheme parameters.
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The study of the flow in the vapour channel of short linear heat pipes
Статья научная
E-mail: seryakovav@yandex.ru The results of studies of flow of moist vapour in Laval-like vapour channels of short linear heat pipes (HPs) are pre- sented. The increase in heat transfer coefficient of short linear HPs, intended for creation of the cooling systems of heat-stressed designs of spacecraft, is carried out by making the HPs vapour channel forms similar to the shape of the Laval-like nozzle. Comparison of the heat transfer coefficients of short HPs with the standard cylindrical vapour channel and the channel, made in the form of the Laval-like nozzle with the equality of all dimensions, flat evaporator and the same amount of the working fluid, shows that the HPs with the vapour channel in the form of the Laval-like nozzle exceeds the heat transfer characteristics of the standard HPs with a cylindrical vapour channel under high ther- mal loads. The study of the flow and condensation in such shaped vapour channels of the short HPs at high thermal loads gives an opportunity to analyze in detail the advantages of using such HPs and make the conclusion about the necessity of wide introduction of such HPs for the cooling systems of the spacecraft. Capacitive sensors were addition- ally installed in cooled top covers of the HPs, and electromagnetic pulses with a frequency of 100 kHz were supplied to them from the external generator. At heating the HPs evaporator, starting from a certain thermal power threshold value, electromagnetic pulses became modulated. It is related to the formations of the boiling process in the capillary- porous evaporator and large amount of vapour over it and its discontinuous distribution. It was discovered that the frequencies of the pulsations are more and they occur at lower values of heat load at the evaporator in the HPs with a vapour channel of a Laval-like nozzle, compared to the HPs with the standard cylindrical vapour channel with equal overall dimensions.
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Статья научная
The applications of space vehicles in the modern world are extensive enough: satellite communication, broadband and narrowband broadcasting, meteorology, scientific research and others. For this reason, modern space vehicles use the latest achievements of science and technology. It allows us to create easy, compact space vehicles with a wide functional. The devices developed in the Research and Production Center “Polus” should meet the requirements of advanced reliability both for regular and for emergency operating modes. One of the scopes of application of such devices is designing of space vehicles. The main task at designing and manufacturing of devices and their components is reliability maintenance. This is a primary requirement to custom-made products for which repair at major failures is extremely labor-consuming. At the same time, serious demands are made to mass, dimensional characteristics, power consumption, payloads, noise characteristics of separate blocks and devices, and other technical parameters. However, it is necessary to consider that at high requirements to characteristics the process of creation of products should be technological. There are various techniques to define reliability of technical devices and their components. One of such ways is carrying out the whole complex of tests simulating a full cycle of operation of the device or a mechanism. However, experimental techniques have essential disadvantages, namely: high cost and long duration. Mathematical modelling allows us to reduce expenses on mock-up designing, engineering time, risks, to reveal weak points, to develop recom- mendations for strengthening the design and to give preliminary conclusions about firmness of the device to loads. Along with thermal, electrostatic and frequency characteristics, mechanical effects play an important role, i. e. dynamic and static loads. In this paper, the results of modelling of external mechanical effects on the device are pre- sented. Numerical modelling of quasi-static loading and effect on the device of random vibration is conducted and the modal analysis is carried out. Oscillation modes of the first three resonant frequencies of the device, stress, displace- ments and accelerations diagrams are obtained. Load factors, the maximum values of displacements and accelerations at impact actions are determined.
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Статья научная
Рассматривается вариант применения нейронных сетей для автоматизации вибрационных испытаний элементов конструкции летательных аппаратов.
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Статья научная
Рассматриваются вопросы электрических испытаний электротехнических систем космических аппаратов (ЭТС КА) с помощью специальных систем, имитирующих электрические характеристики систем электропитания (СИЭХ СЭП) космических аппаратов. Показана актуальность применения таких систем, рассмотрены недостатки известных систем имитации. Предлагается новая автоматизированная система, позволяющая проводить электрические испытания ЭТС КА в штатных и аварийных режимах, исследовать устойчивость бортовых систем к воздействию по шинам питания электромагнитных помех требуемых амплитуды, частоты и формы сигнала. СИЭХ обеспечивает питание ЭТС КА номинальными напряжениями 27 и 100 В, содержит два специализированных источника электропитания (ИСЭП), обеспечивающих выполнение основных целевых функций, и управляющую ПЭВМ. Показано, что в ИСЭП за счет совмещения в управляемом источнике электропитания функций источника питания и генератора помех требуемой формы достигается существенное упрощение структуры, улучшение эксплуатационных характеристик, обеспечивается воспроизведение импедансных частотных характеристик системы электропитания КА. Рассматривается устройство имитатора СЭП с выходным напряжением 100 В (ИСЭП-100), содержащее нерегулируемый источник питания, управляемый стабилизатор выходного напряжения, многофункциональное быстродействующее устройство защиты (БУЗ) и цифровую систему управления и измерения сигналов. Управляемый стабилизатор выходного напряжения выполнен по схеме с двойным регулированием мощности, что позволяет обеспечить требуемые статические и динамические свойства и хорошие массогабаритные характеристики. При этом непрерывный стабилизатор напряжения (НСН) обеспечивает требуемое качество электроэнергии, воспроизводит требуемые импедансные частотные характеристики бортовой СЭП, позволяет наводить на шинах питания тестовые сигналы требуемой формы в диапазоне частот гармонического сигнала до 1 МГц. Импульсный регулятор ограничивает мощность рассеивания НСН путём стабилизации напряжения на транзисторном регуляторе тока НСН. Рассматривается БУЗ, которое отключает ЭТС КА при превышении выходного напряжения, тока нагрузки требуемых уровней и при пропадании фазы промышленной сети переменного напряжения. Время задержки срабатывания БУЗ регулируется в диапазоне от 2 мкс до 1,5 с. Разработанный СИЭХ СЭП позволяет проводить весь комплекс электрических испытаний ЭТС КА, внедрён в эксплуатацию в АО «Информационные спутниковые системы» (г. Железногорск), где использовался для испытаний бортовых ретрансляторов ряда искусственных спутников Земли.
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Статья научная
Рассматривается проблема синтеза систем электропитания космических аппаратов. Предлагается автоматизированная система научных исследований для синтеза систем электропитания космических аппаратов, с помощью которой проводятся исследования систем электропитания различных типов.
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Статья научная
Литий-ионные аккумуляторные батареи (ЛИАБ) широко применяют в качестве накопителей электроэнергии в системах электропитания (СЭП) космических аппаратов (КА). В статье рассмотрен автоматизированный стенд СИА 12/24 для проведения электрических испытаний и диагностики ресурсных характеристик литий-ионных аккумуляторов (ЛИА), на основе которых разрабатываются и изготавливаются ЛИАБ СЭП КА. Ресурсные испытания ЛИА являются наиболее трудоемкими и длительными, их проводят в наземных условиях в течение нескольких месяцев при многократном циклическом воспроизведении режимов заряд/разряд и температур аккумулятора до достижения условий завершения испытаний при периодическом контроле, измерении и регистрации параметров ЛИА. Применение автоматизированного стенда, позволяющего проводить ресурсные испытания ЛИА на основе методики динамического стрессового тестирования (ДСТ), позволяет сократить сроки ресурсных испытаний ЛИА и тем самым существенно ускорить проектирование и отработку ЛИАБ и СЭП КА. Приведены структура, описание составных частей и технические характеристики стенда СИА 12/24, позволяющего проводить электрические испытания одновременно двенадцати ЛИА. Рассмотрены принцип действия и технические характеристики оригинального зарядно-разрядного устройства с нагрузочным преобразователем (ЗРУ-НП), составляющего основу стенда. Предложенные оригинальные топологии ЗРУ-НП и нагрузочного преобразователя (НП) с двухступенчатым преобразованием мощности и стабилизацией входного напряжения мостового трансформаторного преобразователя (МТП) позволяют автоматизировать процесс электрических испытаний литий-ионных аккумуляторов путем автоматического воспроизведения функционально необходимых режимов испытаний и обеспечить энергосбережение в режимах заряда - разряда аккумуляторов. Для ЗРУ-НП с двухступенчатым преобразованием мощности показано, что применение стабилизации входного напряжения МТП позволяет придать НП следующие положительные свойства: - расширение диапазонов регулирования атрибутов ЛИА: тока, напряжения, мощности; - слабую зависимость статической погрешности стабилизации атрибутов ЛИА и показателей качества переходных процессов от типа нагрузки НП.
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Автоматическое устройство наведения на стык при электронно-лучевой сварке
Статья обзорная
Представлена математическая модель комбинированного рентгеновского датчика для электронно-лучевой сварки (ЭЛС), позволяющая связать амплитуду и форму сигнала датчика с местом положения электронного луча относительно стыка. Предложена методика автоматического слежения по стыку, позволяющая повысить точность наведения. Рассмотрена функциональная схема и алгоритм функционирования системы слежения за стыком при ЭЛС.
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Адаптивная эталонная модель в системе управления беспилотного летательного аппарата
Статья научная
Рассматривается система управления с применением адаптивной эталонной модели. Для оценки изменяющихся параметров объекта и последующей адаптации эталонной модели используется блок-идентификатор, построенный с применением нечеткого логического вывода.
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Статья научная
Рассмотрена возможность поддержания продольной устойчивости экраноплана в режиме полета вблизи опорной поверхности при помощи крыла с адаптивной нижней поверхностью. Этот способ обеспечения продольной устойчивости экраноплана может применяться как основной или дополнительный к уже известным.
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Адаптивные многолучевые антенны
Статья научная
Приведен один из вариантов исполнения адаптивной антенны, позволяющий эффективно подавлять помеху с заданного направления, при сохранении уровня сигнала в большей части зоны обслуживания.
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Статья научная
Предложен алгоритм анализа экспериментальных данных при вибрационных испытаниях и процедура расчета уровней нагружения космического аппарата (зависимость ускорения от частоты) в интерфейсе космического аппарата с вибростендом.
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