稀薄等离子体羽流稳态流动粒子模拟

Particle Simulation of Steady Flow of Rarefied Plasma Plume

以稳态等离子体推力器羽流为研究对象,基于单元粒子法-直接模拟蒙特卡罗法混合法,建立数值仿真模型,研究流场电势、电子数密度、离子电流密度分布,通过与实测数据及已有模拟结果的比较验证模型.电子动量方程简化中,考虑电子和离子与中性粒子的碰撞效应,采用交替方向隐式法求解等离子体电势,所得仿真结果优于忽略该效应的Boltzmann模型,尤其是在流场翼部.本研究对电推力器的污染评估具有参考价值.

Taking the plume of a stationary plasma thruster as the research object, and a numerical model based on particle-in-cell （PIC） and direct simulation Monte-Carlo （DSMC） hybrid method was developed to study profiles of the plasma potential, electron number density and ion current density of flow field. Also the model was verified by comparisons between computational results and both experimental data and ex- isting simulation results. The effect of electron-ion and electron-neutral collisions was considered while simplifying the electron momentum equation which was neglected in the Boltzmann model. Then the alternating direction implicit （ADI） approach was employed to solve the plasma potential. The results of this simulation are better than those of simulations with Boltzmann relation, especially at the wing of flow field. Research of this paper is the referable for the contamination assessment of electric thrusters.