碘工质霍尔推力器内部过程数值模拟

Numerical Simulations of the Internal Procedure of an Iodine Fueled Hall Thruster

随着霍尔推力器的大力发展,碘工质霍尔推力器越来越受到研究人员的重视。深入了解碘工质霍尔推力器放电室内部过程,为优化推力器性能和拓展空间应用提供依据。建立了二维PIC/DSMC/MCC混合方法模型,结合鞘层和二次电子发射模型,根据碘工质特性,加入解离-电离过程,在定壁温条件下,针对200 W碘工质霍尔推力器放电室内部过程开展了数值模拟,考察其放电室内等离子体的多场耦合特性以及与壁面的相互作用过程。研究其放电通道内部的等离子体行为,分析放电室内的等离子体参数,获取其离子数密度、离子轴向运动速度、电子温度等特征参数,将模拟结果和氙工质进行比较。结果表明:相较于氙工质,碘工质霍尔推力器存在解离区,宽度约为2 mm,位于近阳极区之后、电离区之前。

With the rapid development of Hall thrusters,iodine fueled Hall thrusters have been paid more and more attention from researchers. In order to deeply understand the internal procedure in the discharge channels of iodine fueled Hall thrusters and provide scientific evidences for optimizing the performances of thrusters and expanding their space applications, a two-dimensional particle-in-cell/direct-simulation-Monte-Carlo/Monte-Carlo-collision(PIC/DSMC/MCC)hybrid model is established with sheath and secondary electron emission. According to the properties of iodine,dissociation and ionization are added. Under the condition of constant channel wall temperature,numerical simulations are carried out for the internal procedure in the discharge channel of a 200 W iodine fueled Hall thruster.The multi-field coupling characteristics of plasma and the interactions between the channel walls and the plasma in the discharge channel are studied. The ion number density,ion axis velocity,and electronic temperature distribution are obtained to study the plasma actions and analyze the parameters of plasma. Compared with xenon,iodine fueled Hall thrusters have a dissociating region with a width of about 2 mm,which is located behind the near-anode region and before the ionization region.