离子推力器束流密度分布模型

Modelling of Ion Beam Current Density of Ion Thruster

束流密度分布模型公式对了解推力器羽流场下游比较大范围内的束流特性,以及在工程应用中对评估离子推力器对舱体的溅射污染效应有重要意义。同时也对地面试验的工况快速确定及结果估计有重要的工程应用价值。然而,现有的两个束流模型均不能很好的描述离子推力器的羽流特性。本文在已有的两个模型的基础上提出了新的束流密度分布模型,并与试验结果相比吻合度较好。本文的束流密度模型与已有的两个模型相比,本文的模型能够更好地描述离子推力器的束流密度分布。

The characteristics of the ion beam current density in the ion thruster,especially in the fairly wide region in the down-stream plume flow-field,was mathematically described with a semi-empirical model,based on the two existing models formulated by R. I. Samanta Roy and Thaine W. Reynolds,theoretically analyzed,numerically simulated and experimentally evaluated with the lab-built,vacuum plume effect experimental system（ PES） for the20 cm Xe ion thruster. The results,calculated with the newly-developed semi-empirical model,agree well with the measured ones. The novel model outperforms the two existing models because of its much smaller discrepancy between the calculated and measured results. We suggest that the new ion beam current density model may be of some technological interest in hybrid PIC simulation as the inlet boundary conditions and in the engineering applications,involving ion erosion and sputtered pollution.