某小推力发动机试验系统自动器故障仿真研究

Taking the fault conditions of automatic actuator failure in a low-thrust liquid rocket engine test system as the research object，the models of the pneumatic liquid valve，the pressure regulator，the combustion chamber and the propellant tank were conducted. And the simulation system was built on Amesim platform. Through comparison between calculated data and test data，the reliability of new models was verified respectively. Furthermore，the simulation effect on the normal working condition of the whole test system was demonstrated，showing that the steady state error of main parameters was less than 2.8%. Based on the normal working condition， the prediction results of fault conditions under failure of the pneumatic liquid valve control cavity leakage and the pressure regulator internal leakage were calculated. The results showed that the chamber pressure can deviate from the normal conditions by 14.3% and the mixing ratio by 37.3% after the failure of pressure regulator internal leakage for 30 s. And when the leakage area of the pneumatic valve reached 24 mm²， the propellant valve was completely closed. The prediction results can be accumulated for further work on fault detection， fault analysis and intelligent control of the test system.