Numerical And Experiment Analysis On Dynamic Characteristic Of Cryogenic Space Propulsion System For Attitude And Orbit Control

Liquid-oxygen / methane engines are one of the hot topics in liquid rocket engines due to their high specific gravity,low coke coke,similar temperature and high compatibility.In this paper,the hydraulic / methane attitude and orbit control system is taken as the research object.The simulation model of the engine system is established by AMESim software,and the dynamic characteristics of the engine on-off process are simulated.In addition,since the solenoid valve has a great influence on the response performance of the liquid oxygen and oxygen methane attitude and orbit control system,the direct acting solenoid valve test prototype is designed and processed,and the experiments and simulation studies are carried out.The thesis first studies the scheme of the liquid oxygen / methane attitude and orbit control system,and describes the working process and principle of the engine with the principle diagram of the power system.According to the overall technical index of the system,by selecting the appropriate theoretical model,the parameters of the powertrain components are designed,which can provide the input conditions for the follow-up dynamic characteristics simulation and the component experiment research.Then the prototype of linear solenoid valve was tested at room temperature and at low temperature.The influence of structural parameters such as pre-tightening force and minimum air gap on working characteristics of the solenoid valve,such as flow resistance and response characteristics,was studied.The influence of circuit parameters on the response characteristics of solenoid valve was studied by numerical simulation.Combining the experiment and the simulation research,we got a deep understanding of the direct acting solenoid valve and provide the reference for the subsequent design of the solenoid valve.Finally,the simulation model of AMESim software was used to analyze the flow characteristics and physical process of the cryogenic fluid passing through the valve,nozzle and other short-pipe throttling pieces.The influence of operating parameters on the pre-cooling filling and start-The influence of propellant temperature and liquid collecting chamber volume on engine off time and thrust after impact.It provides a reference for the design and test of liquid oxygen / methane engine.