基于粒子模拟的舱内布局对霍尔推进器可靠性评估真空羽流的影响

对霍尔推进器地面测试过程中真空环境下的羽流流场进行模拟研究,通过直接蒙特卡洛(DSMC)方法进行多种布局方式下的系列数值模拟,重点研究地面测试设施中舱内的抽氙冷板、束流挡板在不同布局环境下对真空羽流流场的影响。数值模拟结果显示:抽氙冷板的布局位置对羽流流场影响较不明显,但应考虑舱内各处均布以防压力局部集聚过高形成阻力;束流挡板对返流粒子的抑制作用明显,对抽氙冷板等具有较好的防护功能,但也同时改变了羽流流场分布,甚至会影响到推进器的放电特性和性能表现。通过该数值模拟方法可以实现对舱内工艺设备的设计指导,对抽氙冷板、束流挡板等进行布局优化,继而为推进器地面测试提供更为有效的测试环境。

Effect of cabin layout on vacuum plume of Hall thruster based on particle simulation

The plume field in a vacuum facility for Hall thruster ground testing was investigated in detail through a series of simulations using direct simulation Monte Carlo (DSMC) code. The focus here was put on the effects of vacuum plume flow field in testing facility under different distributions of the xenon pump and beam baffle. The results showed that the position of xenon pump had little influence on the plume flow field. However, it should be considered that the xenon pump should be uniformly arranged to prevent locally excessive increase of pressure and formation of resistance. The beam baffle had an obvious inhibitory effect on the backflow particles, and had a good protection function for xenon pump. However, it also changed the plume flow field distribution, even the discharge characteristic and performances of Hall thruster. There were also some considerations for distribution of process equipments to reach a better and real testing environment. The numerical simulation is great beneficial to the design and layout optimization of test facility, which provides a more effective test environment for ground tests of electric propulsion.