电弧喷射推力器化学非平衡数值模拟

Chemical non-equilibrium simulation on arcjet thrusters

关键词:  电弧喷射推进  推力器  化学非平衡模型+  数值仿真  流动分布

Key words:  Arc jet propulsion  Thruster  Chemical non-equilibrium modeling~+  Numerical simulation  Flow distribution

摘要:

为了准确把握电弧喷射推力器工作过程物理机理与特征,采用化学非平衡模型对不同压缩室直径下低功率氮电弧喷射推力器工作情况进行了数值模拟。模型考虑了工作过程中的分解反应、电离反应和复合反应,化学动力学模型为4组分,4反应的有限速率化学反应模型。采用二阶精度NND格式数值求解耦合电磁源项和化学反应源项的N S方程组,采用有限控制容积积分方法求解由麦克斯韦方程组推导出的电磁场方程。数值模拟的结果揭示了推力器内部电弧能量输入作用和高温电离气体的离解电离状况,给出了不同压缩室直径下推力器的推力、比冲和推进效率。结果分析表明,压缩室直径对推力器性能具有较大影响。

Abstract:

To realize mechanism and characteristic of arcjet thrusters operating course perfectly, numerical simulations on operation of low power nitrogen arcjet thrusters with various constrictor diameters were achieved based upon chemical non-equilibrium modeling for them.The factors of decomposition, ionization and composition, which affect the operation, were taken into account in the modeling.Four-ingredient and four-step finite-rate chemical reaction model was adopted in the chemical kinetics model.Non-oscillatory and non-free-parameters dissipative finite difference scheme with second accuracy was used to solve Navier-Stokes equations coupled with electromagnetism and chemical reaction source terms,and finite control volume integral method was applied to solve electromagnetic equation derived from Maxwell’s equations.The results of numerical simulation display energy introducing, decomposition and ionization within the thrusters, and present thrust, specific impulse and thrust efficiency of the thrusters with various constrictor diameters.The results show that constrictor diameters have significant influence on operating performance of the thrusters.