离子推力器羽流沉积对卫星热控影响研究

离子推力器的羽流是等离子体,等离子体的组成是带电粒子,这与传统的化学推进系统的羽流成分有很大不同,带电粒子有在卫星表面吸附的倾向,会形成羽流沉积污染。这种羽流沉积会改变卫星表面的吸收率和发射率,从而影响卫星的热控性能。为了预测离子推力器的羽流对卫星的热控性能的影响,建立了离子推力器羽流模型。所建模型采用了工程化离子推力器的在卫星上的布局位置和离子推力器的工作参数,模拟了离子推力器的正离子与中和电子束在工程化中分置的实际情况,使模型更为符合实际。通过数值模拟得到了离子、电子、中性粒子的空间分布,电场分布,得到了钼粒子在卫星表面的分布及沉积厚度,比较了模型计算的离子分布与实验获得的离子分布情况,说明了模型分析的正确性,给出了卫星表面热性能的变化及局部区域温升的最大包络可达二十多度的结果。

Influence of plume deposit of ion thruster on thermal control properties of satellite

The ion electric thruster plume is plasma that consists of charged particles,which has a tendency to be adsorbed onto satellite surface.The deposition of the plume can change the absorptivity and emissivity of the satellite surface,which has a negative influence on thermal control property of the satellite.In order to predict this influence,a ion thruster plume model was built.The layout position and working parameters of an engineering ion thruster are adopted in the model to simulate the actual conditions of positive ion and electron beam,which makes the model more in accord with reality.The spatial distribution and electric field distribution of ions,electrons and neutral particles,and deposition distribution of molybdenum particles on satellite surface were obtained with numerical simulation.The ion distributions got by simulation calculation and experiment was compared,which validated the correctness of the model analysis.The thermal property of the satellite surface and the maximum envelope of temperature increase in local region of the satellite surface are given in this paper.