小功率直流氨电弧等离子体推力器性能和等离子体特性研究

项目名称： 小功率直流氨电弧等离子体推力器性能和等离子体特性研究

项目编号： No.11475239

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 孟显

作者单位： 中国科学院力学研究所

项目金额： 96万元

中文摘要： 卫星小型化的应用发展对其在轨精确定位的小推力器技术提出了迫切需求。本项目依此背景，选择空间电推进中有成熟应用积累、结构简单、易于小型化、与卫星系统协调性好的电弧加热推进方法，以高密度方便携带且安全性好的氨为推进剂，采用实验诊断为主，辅以理论分析和数值模拟的方法，对低于100W的推力器放电参数、0.3mm直径通道内放电行为、在阳极表面贴附形态、离开喷管的羽流状态、推力器产生的毫牛级推力进行实时观测；数值模拟由连续介质流动向自由分子流过渡的等离子体流动；分析阳极/喷管内的能量转换过程。系统研究推力器结构和工作参数对等离子体放电模式、伏安特性、羽流参数以及推力器性能的影响，探寻约0.1mm直径的氨电弧在高达10000Pa/mm的流向压力梯度下稳定运行的参数组合，掌握影响稳定放电和推力器性能的主控因素；深化对该类等离子体放电过程、特性和机理的认识，为高性能小功率氨等离子体推力器设计提供参考数据。

中文关键词： 直流电弧等离子体；小功率；放电特性；参数诊断；数值模拟

英文摘要： In recent years, with the development of the satellite miniaturization, there has been an urgent need for small propulsion thruster technology with the purpose of obtaining precise location in orbit. Arc-heated plasma thruster is one type of electric propulsion device, which has had long periods of successful applications, is simple in structure, and can be made compatible with the small satellite system. Ammonia is a propellant of high density, easily storable and safe to carry on board. In this project, very-low-power DC ammonia arc plasma thruster will be investigated, mainly experimentally, supplemented by theoretical analysis and numerical simulation. For the plasma thruster with arc power lower than 100W, electric discharge behavior within the 0.3mm-diameter channel, the arc root attachment on the inner wall of the anode, plasma plume status leaving the nozzle exit, and mN class thrust produced by the thruster will be experimentally studied. Numerical methods will be used to simulate the plasma flow from continuum to free molecular, and to analyze the energy conversion process within the nozzle. The effect of thruster structure and working parameters on the arc discharge mode, volt-ampere characteristics, plume parameters and thruster performance will be systematically investigated. The parameter combinations enabling stable operation of the thruster under the extreme conditions of pressure gradient up to 104 Pa/mm in the small discharge channel of 300 ?m will be explored. Through these studies, the main factors controlling stable discharge and performance of the thruster, the discharge processes and mechanisms of this kind of DC arc plasma will be better understood, and they will also provide reference data for the design of stable and high performing very-low-power ammonia plasma thruster.

英文关键词： DC arc plasma;low-power;discharge characteristics;parameter diagnostics;numerical simulation