脉冲等离子体推力器羽流场数值分析

为掌握脉冲等离子体推力器的羽流特性，考虑磁场对等离子体羽流的影响，结合DSMC和PIC方法建立了粒子-流体混合模拟模型，以磁流体力学模拟提供入口条件对推力器羽流开展了三维数值研究，并通过朗缪尔三探针诊断对计算结果进行了验证。研究表明，羽流膨胀过程中各组分的动力学行为差异明显；放电电流振荡会导致产生低速离子群，并会加重离子回流；电磁加速是羽流等离子体主要的加速机制，磁场对推力器羽流的流动具有重要作用。

Numerical analysis of plume field of a pulsed plasma thruster

Considering the effect of magnetic field on the plasma plume, a hybrid particle-fluid model combining DSMC and PIC methods was developed to study the plume characteristics of a pulsed plasma thruster. By incorporating a magnetohydrodynamic code to provide inlet conditions, this model was applied to simulate the three-dimensional plume field. The calculation results were validated by an experiment based on triple Langmuir probes. Investigations show that there are substantial differences between the expansion dynamics of various species. It is indicated that the oscillation of discharge current will lead to the generation of a population of low-velocity ions, together with the aggravation of backflow of ions. Electromagnetic acceleration is demonstrated to be the primary mechanism of plasma acceleration, and the magnetic field plays an important role in the diffusion of the thruster plume.