自由分子流微电热推力器流动模拟与性能预示

Flow Simulation and Performance Prediction of Free Molecule Micro-resistojet

为了精确的预示自由分子流推力器（FMMR）在不同工质、工况下的性能，采用直接模拟蒙特卡罗（DSMC）方法模拟FMMR内气体流动，计算了不同工质气体、工作压强和加热温度条件下的FMMR推力、比冲等性能，分析了工质、工作压强和加热温度对FMMR性能的影响。计算和分析结果表明，工质气体的选择不影响FMMR的推力性能，但随着工质气体相对分子质量的减小，推力器比冲迅速增加；在总压50～500Pa，温度300～600K条件下，推力器的比冲随总压和加热温度的增大而增加，推力随加热温度增大而减小，随总压增大而增大。

To accurately predict the performance of FMMR, under different propellant and working conditions, Direct simulation Monte Carlo method was used to simulate the gas flow in FMMR. The thrust and specific impulse of FMMR were calculated, and the influence of propellant types, working pressure as well as heating temperature on the performance of FMMR was studied. Results of calculation and analysis show that the propellant kind has no effect on thrust, while specific impulse rapidly increases with the decreasing of propellant molecule weight; the specific impulse of FMMR increases with the height of working pressure and heating temperature, and thrust increases with the increasing of the working pressure but decreases with the increasing of the heating temperature.