磁等离子体动力推力器加速机理研究与仿真

Study and simulation of acceleration mechanism of magnetoplasmadynamic thruster

磁等离子体动力推力器具有高比冲、大推力的特点,是一种非常有前途的空间电推进形式。为进一步提高推力器的性能,需要进行强磁场下的推力器加速机理研究。与传统小功率电推力器相比,磁等离子体动力推力器功率大,推进剂流量大,导致实验研究难度大,成本高,存在一定的危险性。利用等离子体电导率模型和磁流体方程组,对强磁环境下推力器进行建模,在0.2、0.53、0.66、1.54 T不同磁场强度下进行了仿真。结果表明,推力器比冲和电压随着磁场强度的提高而增加,比冲变化范围3400~4650 s,电压变化范围120~236 V,推力器效率先增加、后减小,从60.8%增加到72.6%,最后减小到57.9%。研究结果表明,磁流体模型和电导率模型能够反映出磁场对等离子体的加速作用,磁场强度会影响比冲和效率。该模型可为以后推力器的设计和优化提供参考。

The magnetoplasmadynamic thruster is a very promising space electric propulsion system with high specific impulse and high thrust.To further improve the performance of the thruster,it is necessary to study the acceleration mechanism of the thruster under a strong magnetic field.Compared with the traditional low⁃power electric thrusters,the magnetoplasmadynamic thrusters have larger power and larger propellant flow,which leads to the experimental research is difficult because of the high cost and certain dan⁃gers.The plasma conductivity model and the magnetohydrodynamics equations were used to model the thruster in the strong magnetic field,and the simulation was carried out under different magnetic fields of 0.2 T,0.53 T,0.66 T and 1.54 T.The results show that the specific impulse and voltage of the thruster increase with the increase of the magnetic field,the specific impulse changes from 3400 s to 4650 s,and the voltage changes from 120 V to 236 V.The efficiency of thruster first increases from 60.8%to 72.6%and then finally decreases to 57.9%.The research show that magnetohydrodynamics model and conductivity model can reflect the acceleration effect of magnetic field on plasma,and magnetic field strength can affect specific impulse and efficiency.The model can provide ref⁃erence for the design and optimization of thrusters in the future.