集气腔总压对电弧喷射推力器工作过程的影响

为了研究集气腔总压对电弧喷射推力器工作过程的影响,在分析其工作机理的基础上采用化学非平衡流动和稳态电磁流体电磁场模型对不同集气腔总压下推力器工作过程进行了数值模拟.流体力学方程组和电磁场方程考虑了多种流动机理及电磁场与高温电离气体的相互作用,化学动力学模型考虑了各种碰撞反应.采用二阶精度NND格式求解流体力学方程组,采用有限速率化学反应模型计算组分生成率,采用交替方向隐式(ADI)超松弛迭代法求解电磁场离散方程.给出了不同集气腔总压下推力器内部参数分布及其宏观性能.研究表明,集气腔总压对推力器工作过程具有多方面的影响,在保证电弧稳定的情况下,适当提高集气腔总压可同时提高比冲和推进效率.

Effect of plenum chamber total pressure on arcjet thruster operation

To investigate effect of plenum chamber total pressure on arcjet thruster operation, numerical simulation of operation under various plenum chamber total pressures was performed on the basis of mechanism analysis on its operation and modeling for chemical non-equilibrium flow and steady state electromagnetic field within it. Various flow mechanisms and interactions between electromagnetic field and high temperature ionized gas were covered in the fluid dynamic and electromagnetic equations, and various impact reactions were taken into account in the chemical dynamics model. Non-oscillatory and non-free-parameters dissipative (NND)finite difference scheme (a total variation diminishing scheme) with second order accuracy was adopted to solve the fluid dynamic equations, a finite rate chemical reaction model was developed to calculate ingredient producing rate, and an ADI over relaxation iteration technique was used to solve the electromagnetic discretized equations. Parameter distributions within the thruster and its macroscopical performance were presented. The investigation shows that plenum chamber total pressure has multifarious effects on arcjet thruster operation, and both specific impulse and thrust efficiency can be improved by increasing it befittingly under steady arc.