小推力推进系统起动过程的分析

本文对小推力推进系统各部件建立了数学模型，并对此系统进行了数值计算。计算结果表明，在燃烧时滞较大时，该系统响应较慢，发动机参数的超调量较大，达到稳态所需的时间较长；轨控发动机与姿控发动机共用同一个供应系统时，姿控发动机受燃烧时滞的影响更大。减小燃烧时滞有利于提高发动机在起动过程的响应能力和稳定性。在起动阶段，高室压推进系统比低室压推进系统响应快，高室压轨控发动机的参数能较快地稳定下来，但其超调量较大；高室压姿控发动机虽然响应快，但其超调量大，达到稳态所需的时间长于低室压姿控发动机。本文所得结论为提高小推力推进系统在起动过程的响应能力提供了参考。

ANALYSIS OF THE STARTING PROCESS OF LOW THRUST PROPULSION SYSTEM

The mathematical model of the components of low thrust propulsion system and the numerical computation for the system are presented The computed results show that if the combustion time delay is greater,the response of propulsion system becomes slower,the overshoot of engine parameter becomes greater,and the time required for reaching the steady state becoms longer Orbit control rocket engine and attitude control rocket engine share the same propellant feed system,thus attitude control rocket engine is affected more greatly by combustion time dealy Accordingly,decreasing combustion time delay is favourable to improve the response characteristics and stability of the engine during startup The computed results also show that the propulsion system response of high pressure chamber is faster than that of low pressure chamber during startup The orbit control rocket engine with high pressure chamber can be stabilized more quickly,but its overshoot of engine parameters is greater than that of the orbit control rocket engine with low pressure chamber Although the response of the attitude control rocket engine with high pressure chamber is faster,its overshoot of engine parameters is greater,and the time required for reaching the steady state is longer than that of the attitude control rocket engine with low pressure chamber The conclusions obtained provide the reference for improving the response characteristics of low thrust propulsion system during startup