非轴对称性对霍尔推力器等离子体流动过程的影响研究

The Hall thruster is an electromagnetic plasma discharge system which has been widely used for various space propulsion missions. Compared with the traditional electric propulsion system, the movement of charged particles under electromagnetic condition must be considered in Hall thrusters, which makes its complicated working mechanism. Experimental results show that, the transport process of the working gas, magnetic field, wall profile and some other factors can lead to the non-axisymmetric distribution, which makes the increase of plume divergence angle and finally the reduction of thruster performance...A new viewpoint is proposed in this proposal that the influence of non-axisymmetric characteristics on plasma flow inside Hall thruster should be studied. Non-axisymmetric characteristics can destroy the stable and closed electron Hall drift, induce azimuthal plasma oscillation, increase electron conductivity, further influence ions’ movement and finally decrease the performance of the thruster. The proposal will do the research by numerical simulation combined with experiments, aiming at understanding the mechanism of non-axisymmetric characteristics on plasma behaviors and thruster performance. Through the project development, the systematic study on the generation mechanism of the non-axisymmetric characteristics and its influence on plasmas will be done. It will provide theoretical direction on the optimal design of Hall thrusters.

霍尔推力器是一种新型的航天动力装置，相对于化学推进，霍尔推力器需要考虑带电粒子在电磁环境下的流动过程，机理更为复杂。目前霍尔推力器设计主要基于轴对称模型，但是存在工质输运、磁场和壁面等非轴对称因素。较强的非轴对称性会增大推力器羽流发散角，降低推力器效率，严重限制了霍尔推力器性能的进一步提升。.本课题首次提出采用数值模拟、理论分析结合实验的研究手段，系统研究非轴对称性对霍尔推力器工质流动过程的影响机制。首先分析非轴对称条件下的电子周向霍尔漂移运动，研究非轴对称性所诱导的周向等离子体振荡。在此基础上，进一步分析非轴对称性对电子传导和电势分布的影响，研究其导致的工质电离和加速过程的变化。最终得到非轴对称性与霍尔推力器性能参数的相互关系。通过本课题的开展，能够进一步理解霍尔推力器物理过程，完善霍尔推力器等离子体流动理论，最终为霍尔推力器的优化设计提供指导。

霍尔推力器是一种新型的航天动力装置，相对于化学推进，霍尔推力器需要考虑带电粒子在电磁环境下的流动过程，机理更为复杂。目前霍尔推力器设计主要基于轴对称模型，但是存在工质输运、磁场和壁面等非轴对称因素。较强的非轴对称性会增大推力器羽流发散角，降低推力器效率，严重限制了霍尔推力器性能的进一步提升。.课题首次采用数值模拟、理论分析结合实验的研究手段，系统地研究了非轴对称性对霍尔推力器工质流动过程的影响机制。首先分析了霍尔推力器的非轴对称性的来源及影响因素，评估了各种非轴对称性因素对电子传导和等离子体参数的影响规律，研究非轴对称性所诱导的周向等离子体振荡。在此基础上，进一步分析了非轴对称性导致的工质电离和加速过程的变化。最终得到非轴对称性与霍尔推力器性能参数的相互关系，对霍尔推力器进行改进设计。新研制的霍尔推力器具备推力大范围连续可调、推力稳定、寿命长等优势，通过课题的研究分析了其在重力场测量、引力波探测等高精度任务中的应用前景。.基于以上研究成果，发表SCI论文16篇，在科学出版社出版专著一部。与项目相关的研究成果共授权专利12项。本项目的研究成果在小型霍尔推力器设计中得到成功应用。研制的微牛级会切型霍尔推力器为我国空间引力波探测任务无拖曳控制的方案之一。该推力器作为支撑技术获批国家重点研发计划一项。同时作为关键技术之一，获国家科技进步二等奖一项。