惯性静电约束推力器放电过程数值模拟研究

Numerical Simulation of Discharge Process of InertialElectrostatic Confinement Thruster

关键词:  电推进  惯性静电约束  等离子体  漂移-扩散  仿真模拟

Key words:  Electric propulsion  Inertial electrostatic confinement  Plasma  Drift-diffusion  Simulation

摘要:

为了研究惯性静电约束推力器（Inertial Electrostatic Confinement Thruster，IECT）的放电原理和工作机制，采用漂移-扩散流体模拟方法，基于圆柱形惯性静电约束推力器的结构，研究不同栅网线直径、栅网个数、推力器尺寸条件下等离子体放电情况和阴极电压、背景气压对推力器放电的影响。结果表明：在所研究条件下，保证阴极必要的几何透过率的同时，适当增加推力器栅网个数可以提高喷射离子密度，减小羽流发散角；随着阴极电压和背景气压的增大，推力器喷射的等离子体密度增大。但是，压强继续增大会达到临界值，等离子体被约束在推力器内部无法喷出，即喷射模式无法运行，故阴极电压与背景气压对IECT均有较大影响。

Abstract:

Inertial Electrostatic Confinement Thruster (IECT) is a new type of electrostatic plasma thruster with simple structure, long life and resistance to ablation. In order to study the discharge principle and working mechanism of the thruster，the drift-diffusion fluid simulation method is used to study the plasma discharge with different grid wire diameters, grid number, thruster size and the impact of cathode voltage, background pressure on thruster discharge based on the structure of the cylindrical IECT. The simulation results show that with the necessary geometric transmission of the cathode, increasing the number of thruster grids can increase the jet ion number density and reduce the plume divergence angle on study condition. The plasma density of the thruster jet increases as the background pressure and cathode voltage increase. However, if the pressure continues to increase, the critical value will be reached. The plasma is constrained inside the thruster and unable to be ejected, the injection mode cannot be operated. So the cathode voltage and the background pressure have a great influence on the IECT.