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Table of Content

    25 June 1994, Volume 14 Issue 03 Previous Issue    Next Issue
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    A VIBRATION PROPAGATION MODEL UPON AXISYMMETRIC VISCOUS LIQUID BRIDGES IN MICROGRAVITY
    Wang Xianrong(Lanzhou Institute of Physics, Lanzhou 730000)
    1994, 14 (03):  . 
    Abstract ( 1845 )   Save
    his paper establishes a vibration propagation model upon axisymmentric viscous liquid bridges in a viscous bath under the microgravity condifions. The model takes into account the viscous effects of both liquid bridge and surrounding bath and includes these effects in a corresponding uniform mathematical equation group. The solution gives the mathematical expressions of the interface deformation function for bridges with equilibrium vibration state and the other concerned significant results,which are similar to the conclusions got by Cosserat Modeland LinearThree-Dimension Model.
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    CALCULATION OF ALBEDO AND INFRARED VIEW FACTORS OF ARBITRARY CONCAVE SURFACES AND MUTUALLY VISIBLE SURFACES
    Wand Jianhua; Pan Zengfu(Beijing Institute of Spacecraft System Engineering, Beijing 100086)Min Guirong(Chiness Academy of Space Technology, Beijing 100081)
    1994, 14 (03):  . 
    Abstract ( 1563 )   Save
    ormulas for calculating albedo Yiew factors φ2, and infrared view factors φ3, of arbitrary concave surfaces and mutually visible surfaces have been devised, and on the basis of Monte Carlo Method, the factors of various surfaces such as hemispheric concave surface,parabolic concave surface, two mutually visible and vertical flat plates and outer cylinder surface on the bottom of which there is a flat plate, haye been calculated.The results shows albedo and infrared view factors of that kind of shapes can be calculated practically by using above method.
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    MATHEMATICAL PROCESSING TO TRACKING DATA OF RANGE AND RANGE RATE
    Wang Zhengming Zhou Haiyin(Dept of Math, National Univ .of Defense Technology, Changsha 410073)
    1994, 14 (03):  . 
    Abstract ( 1519 )   Save
    y means of tracking measure of a space vehicle, measuring data of range and range rate can be obtained by using radar or optical instrument. Because of inaccuracy of measuring instrument, surrounding conditions, etc.,system errors are included in the obseryation data of range besides random errors of range and range rate. This paper have obtained a method to estimate the range, range rate and system errors of range by means of setting up a suitable mathematical model, using spline function theory and repression analysis. The calculation using our method is easy.Theory analysis and simulation results indicate the high accuracy of our method.
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    GLOBAL PERSONAL MOBILE-SATELLITE COMMUNICATIONS SYSTEM
    Chen Daoming(Chinese Academy of Space Technology, Beijing 100081)
    1994, 14 (03):  . 
    Abstract ( 1713 )   Save
    Personal Communications Systems(PCS)are made of independently developing concepts.Now in the 1990's it have been growing in using orbits other than the geostationary orbit for telecommunications satellites.It is the best approach to use the Low Earth Orbit(LEO) satellites.The use of LEO satellites will be in a manner similar to that proposed for extension of cellular networks and offer many of the same services.The evolution of mobile communications satellite is reyiewed in this paper.A perspective on future networks of low earth orbit satellite is presented, along with conclusion remarks on legal, administrative problems.This paper describes the functional structure of PCS. Some main technical features of several LEO networks are presented in the table for comparison.
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    FY-2 GEOSTATIONARY METEOROLOGICAL SATELLITE SYSTEM AND ITS APPLICATION PROSPECTS
    Qiu Kangmu(Satellite Meteorology Center, Beijing 100081)
    1994, 14 (03):  . 
    Abstract ( 1498 )   Save
    he text briefly introduces FY-2 geostationary meteorologicalsatellite, the ground application system and the remote sensing products,and makes a preliminary analysis and prediction of t he possible application prospects, of the remote products
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    MATRIX MANAGEMENT AND TWO COMMANDING LINES IN SATELLITE PROJECT DEVELOPMENT
    Yang Weiyuan(Chinese Acadmy of Space Technology, Beijing 100081)
    1994, 14 (03):  . 
    Abstract ( 1637 )   Save
    his paper studied the issue of deeply transforming management organization in a satellite project deyelopment. It presented a commonly used matrix management system in multi-satellite projects and pointed out the function of "two commanding lines" in matrix management. Finally,it proposed a way to strengthen "two commanding lines.
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    DYNAMIC MODEL AND BEHAVIOUR OF SPACE RENDEZVOUS
    Lin Laixing(Beijing Institute of Control Engineering, Beijing 100080)
    1994, 14 (03):  . 
    Abstract ( 1969 )   Save
    In this paper relative motion equation of space rendezvous is investigated and four types of dynamic model are derived. The dynamic characteristics of this model are analysed. Relations between motion trajectory and initial conditions have been found.Finally, the comparison between the proximate model and the precise model and their analyses are made.
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    TECHNIQUE OF ANALYSIS AND DESIGN FOR DIGITAL CONTROL SYSTEMS
    He Yunguo; Cui Shaochun(Beijing Institute of Space Machine and Electricity, Beijing 100076)
    1994, 14 (03):  . 
    Abstract ( 1658 )   Save
    This paper discusses a method of analysis and design in of a typical sample control system-direct digital control(DDC) system S and P domains.According to the theory of sample-data control systems, by starting from the stability criterion of digital control system in Z-plane and using tustin transform(p-transform) and the relations between Z-plane,S-plane and P-plane, the stabitity criterion for digital control systems in S and P domains is conducted.Further more,the analysis and design method digital control systemsin S and P domains is put forward.
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    REVIEW AND RESEARCH ON CARBON-FIBRE-REINFORCE QUARTZ USED AS THERMAL PROTECTION SHIELD
    Wu Guotiug(Boijing Institute of Spacecraft Systems Engineering, Beijing 100086)
    1994, 14 (03):  . 
    Abstract ( 1512 )   Save
    Fibre-reinforce ceramics used as thermal protection shield is reviewed and rescarched. Based on the typical mechanical and thermody namic environment of a returnable spacecraft, a series of tests on carbonfibre-reinforce quartz are made, including reentry thermal simulation test of small plates, vibration and shock at room and very low temperature tests of large thermal-protection structure models and reentry thermal simulation tests with large models. These tests quilify the carbon-fibre-reinforce ceramics for thermal protection shield of returnable spacecraft.
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