射频离子推力器热特性仿真分析

Simulation Analysis of Thermal Characteristics of RF Ion Thruster

关键词:  电推进  感性耦合等离子体  热模型  能量沉积  温度分布

摘要:

为了分析射频离子推力器热特性，建立了射频离子推力器整体热模型，基于二维流体模型，对11cm射频离子推力器开展了放电室等离子体仿真，获得了电子温度、电势分布等关键参数；以等离子体仿真结果和实测束电流为输入，获得了各热源的热通量；通过有限元计算获得了关键部组件的温度分布，与实验结果进行了对比分析。研究结果显示：放电室内电子温度约为3.6eV~3.9eV，等离子体电势最高20V，发热损耗主要来自带电粒子轰击放电室壁面和栅极造成的能量沉积、激发原子的热辐射以及射频线圈自身的发热损耗，温度仿真与实测结果一致性良好，最大误差7%，仿真得到的温度分布可以作为输入参数进一步研究栅极受热形变及对束流的影响。

Abstract:

In order to analyze the thermal characteristics of RF ion thruster, the global thermal model of RF ion thruster was established, a two-dimensional simulation of plasma in discharge vessel based on a fluid model was carried out on a 11cm RF ion thruster, the key plasma parameters including electron temperature and potential were solved. The heat flux of each heat source was obtained by using the plasma simulation results and measured beam current as inputs. The temperature of main components are obtained by using finite element software. The distribution was finally compared with the experimental results. The results show that the electron temperature in the discharge vessel is about 3.6eV~3.9eV, and the plasma potential is up to 20V. The heat loss mainly includes the energy deposition of charged particles on the inner wall of discharge vessel and grids, the radiation of the excited atoms, and the heat loss of the RF coil. The simulation and experimental results are in good agreement, the maximum error is no more than 7%. The temperature distribution obtained by the model can be used as an input parameter to further study the thermal deformation of grids and its influence on ion beam.