附加场强度对低工况AF-MPDT性能的影响

Effects of the intensity of applied magnetic field impacted on AF-MPDT performance operated at low power

附加磁场强度与位形是大功率磁等离子体动力推力器(Applied Field Magnetoplasmadynamic Thruster, AF-MPDT)重要工作参数之一。为验证附加磁场强度对低工况下AF-MPDT性能的影响,采用北京控制工程研究所联合北京航空航天大学研制的100 kW级AF-MPDT原理样机,利用推力靶测量系统进行高温震动环境下的推力测量,针对不同附加磁场强度(30～230 mT)下的推力器开展中低功率性能研究实验。实验结果表明,在一定范围内,增加磁场强度可提升低工况下推力器推力、比冲、放电电压及效率等性能指标,并且放电电流越大,性能提升效果越明显。分析表明,低工况下AF-MPDT推力、比冲与磁场强度的平方根呈线性关系;推力器放电电压与磁场强度呈线性关系;推力器效率随磁场强度增强而增加,最终达到相应工况下的极限。

Intensity and profile of applied magnetic field are working parameters of great significance for the applied field magnetoplasmadynamic thruster(AF-MPDT).A 100 kW AF-MPDT principle prototype developed by Beijing Institute of Control Engineering and Beihang University was used to estimate the performance of MPDT under medium power with applied magnetic field varied from 30 mT to 230 mT.A target thrust measurement method under high temperature and vibrating environment was applied.The test results show that within a certain range,increasing the intensity of applied magnetic field could improve the thrust,impulse,discharge voltage and efficiency of AF-MPDT under low power.Besides, the performance improvement of AF-MPDT is more obviouse under higher discharge current.Further analysis shows that when the AF-MPDT was operated under low power, thrust and impulse are proportional to the square root for intensity of magnetic field;discharge voltage is proportional to intensity of magnetic field;efficiency increases with intensity of magnetic field but finally reaches the up limit under the corresponding working condition.