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Table of Content

    25 December 1995, Volume 15 Issue 06 Previous Issue    Next Issue
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    ON THE APPLICATIONS AND DEVELOPMENT OF CRYOGENIC WIND TUNNELS
    You Lixin; Cheng Keming(Nanjing University of Aeronautics & Astronautics, Nanjing 210016)
    1995, 15 (06):  . 
    Abstract ( 1898 )   Save
    he reasons why cryogenic wind tunnels (CWT ) may increase Reynolds number are discussed; the principles and characteristics of high Reynolds aerodynamic test, hot jet simulation test for flight vehicles and high Reynolds number/high Grashof number/high temperature ratio convective heat transfer research by cryogenic wind tunnels are analysed. The results show that cryogenic wind tullnelshave many outstanding advantages when those tests are in comparison with conventional methods and have a lot of meaning for aeronautics and astronautics sciences. The available approaches to construct cryogenic wind tunnels in China are suggested. Finally, some important special key technological problems associated with cryogenic wind tunnels such as working temperature choices, refrigeration and control system, insulation system, wind tunnels model and data measurement are discussed in detail.
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    MEASURES FOR REDUCING LARGE ROCKET HULL STRAIGHTNESS ERROR IN BENDER FORMING
    Xu Furen; Gu Peizhi(Shanghai Machinery Technology (Shanghai Jiao Tong University,Institute, Shanghai 200031) Shanghai 200030)
    1995, 15 (06):  . 
    Abstract ( 1657 )   Save
    P to now, how to reduce more effectively the large rocket hull straightness error has been an interesting problem for technicians of manufacturing rocket hulls. On the basis of systematical analysis, calculation and investigation on the distribution law of the center roller feeding value over the axis of itself under the most disadvantageous practical operation conditions, an inequality for calculating the straightness error of the large rocket bull formed by the bender with three rollers is derived by the author. Relationships between the straightness error of the large rocket hull and geometrical parameters of three rollers in the bender are shown by the inequality. According to the results of studying and comparing the relationships, the author indicates that improving the bender with three rollers is the important way for reducing the straightness error of a large rocket hull. It has been proved by a series of researches that improving the bender with three rollers by use of the method recommended in this paper can make the large rocket hull straightness error reduced considerably.
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    DISCUSSION ON DEVELOPMENT OF CHINESE RETURNABLE SPACECRAFT
    Wang Xiji(Chinese Acadmy of Space Technology, Beijing 100081)
    1995, 15 (06):  . 
    Abstract ( 1942 )   Save
    In the technical point of view, it is logic that the returnable spacecraft will be developed from expendable to reusable. The technical and economic analyses show that China should not develop the space shuttele as the manned spacecraft. It is appropriate for China to develop reusable manned space capsule. China ought to continue developing the expendable and partly harmlessly damaged returnable satellites and develop the technology of reusing the recovered payloads.
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    SPACE DOCKING DYNAMICS SIMULATION SOFTWARE DODASS AND ITS ENGINEERING APPLICATION
    Qu Guangji; Yu Dengyun; Zeng Xin; Wang Ning(Beijing Institute of Spacecraft Systems Engineering,Beijing 100086)
    1995, 15 (06):  . 
    Abstract ( 1638 )   Save
    Firstly, the purpose, technical key and the content of researching the space docking dynamics, and the method and steps for establishing docking dynamics model are described in brief. Then, according to the dockingmechanism system of androgynous and peripheral type, the DODASS simulation program developed by the docking dynamics model and its engineering application simulation curves areintroduced emphatically. finally, a preliminary conclusion providing a reference for engineering design is given.
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    STUDIES OF SIMPLIFIED NUMERICAL MODEL IN CONTINUOUS FLOW ELECTROPHORESIS
    Cai Li; Tao Zulai(Institute of Mechanics,Chinese Academy of sciences)
    1995, 15 (06):  . 
    Abstract ( 1589 )   Save
    n this paper used the finite-analytic method to solve the threedlmenslonal eletrohydrodynamlcal equations. The results show that Polezhaev’s simplified numerical model Is not correct when there exist reverse flow zones under the normal gravity environment.In order to tackle the shortcoming of Polezhaev’s model,a new slmplified numerical model is Proposed in the Paper,which can be used under both microgravity and normal gravity environments. The numerical results are favorable compared with the results obtained from three dimensional model.
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    A TWO-IMPULSE OPTIMAL CONTROL FOR SPACE RENDEZVOUS AND DOCKING
    Lin Laixing; Wang Lixin(Beijing Institute of Control Engineering, Beijing 100080)
    1995, 15 (06):  . 
    Abstract ( 1698 )   Save
    n this paper,a simple and minimun-fuel control stratagy for space rendezvous by two impulses is presented. A first impulse is designed to produce an essentially coasting trajectory which intercepts the target at time T. At that time, a braking velocity increment (second impulse) is added in order to stop the relative motion. Fuel consumption is minimized by selecting the rendezvous time T. Finally, the dynamic characteristics of rendezvons and docking are analysed through mathematics simulation.
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    STRATEGY OF APPLICATION OF FAILURE DIAGNOSIS TECHNOLOGY TO CHINESE SPACE FIELD
    Rong Jili; Huang Wenhu; Ji Changwei(Harbin Institute of Technology Harbin, 150001)Yang Hong; Wang Hao(Beijing Institute of Spacecraft Systems Engineering, Beijing 100086)
    1995, 15 (06):  . 
    Abstract ( 1874 )   Save
    This paper presents a strategy of the application of failure diagnosis technology to chinese space field. The aim of this technology research is to build expert system of failure diagnosis for spacecraft. With respect to system function,development direction, system configuration, key technologies involved, stage classification of technology development and suggestion to technology implementation, some points of view are advanced.
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    STUDY OF VENTURI IN SPACE SIMULATOR LIQUID NITROGEN SYSTEM
    Liu Botao; Sun Laiyan; Yu Pinrui(Beijing Institute of Spacecraft Environment Engineering, Beijing 100101)
    1995, 15 (06):  . 
    Abstract ( 1603 )   Save
    This paper analyses the working principle of Venturi and its use in liquid nitrogen system. The experiments with Venturi were also introduced into a space simulator to verify our concept. The obtained results are valuable for us to design new space simulator liquid nitrogen system.
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