无拖曳卫星氮气微推进系统填充与开机工作特性的仿真研究

采用AMESim软件对氮气贮存压力为1.5×10 7 Pa、推力范围为mN级的压电驱动的氮气微推进系统进行建模。研究了氮气填充过程中氮气瓶、减压阀的压力和质量流量瞬态特性。分析了整合喷管的压电比例阀在开机过程中的瞬态工作特性。最后，研究了驱动电压对压电比例阀在开机过程中的阀芯位移和喷管推力瞬态值、阀芯运动和推力响应时间的影响规律。结果显示，当驱动电压为80 V时，阀芯的响应时间和稳定位移分别为 0.64 ms 和3.67 μm。开机后8 ms，喷管推力达到稳定值(0.588 mN)。压电比例阀阀芯的开启响应快速，且驱动电压与喷管推力之间存在良好的线性关系，说明推力可通过改变驱动电压进行mN级的线性调节。

Simulation Study of Filling and Starting Operation Characteristics ofNitrogen Gas Micro Propulsion System on a Drag Free Satellite

 A numerical model is established using the AMESim software for the operation performance of a nitrogen micro-propulsion system driven by a piezoelectric valve with a nitrogen storage pressure of 1.5×10 7 Pa and a thrust range of mN level. The transient pressure and mass flow of the nitrogen tanks and the pressure reducing valve during nitrogen filling are calculated and analyzed. The transient characteristics of the piezoelectric proportional valve integrated with a nozzle under the starting conditions are also studied. Consequently, the effects of the driving voltage on the displacement of the valve core, the transient thrust of the nozzle, and the response time of the valve core and thrust force are investigated. The results show that the response time and stable displacement of the valve core of the piezoelectric proportional valve are 0.64 ms 〖JP2〗and 3.67 μm respectively as the driving voltage is set to 80 V. The nozzle thrust reaches a stable value (0.588 mN)〖JP〗 at 8 ms after startup. The piezoelectric proportional valve is of a quick response in the movement of the valve core, and there is a good linear relationship between the drive voltages and thrust forces under the starting conditions. This indicates that the thrust linear control at the level of mN can be achieved by changing the driving voltage.