摘要
基于微机电系统技术的自由分子流微电热推力器(FMMR)是一种微型电热推力器,它具有集成化程度高、体积小、质量轻、响应速度快、推质比高、可靠性高和易于集成为推进阵列等特点,它在军事和民用微/纳航天器方面有广阔的应用前景。通过建立合理的数学模型,如分子与壁面相互作用模型采用CLL模型,分子模型采用变径硬球模型,分子碰撞对的选取采用取舍方法。采用直接模拟蒙特卡罗方法结合信息保存法对FMMR的流动特性进行了数值模拟计算和性能计算,并对影响推力器性能的各种因素进行分析。计算和分析结果表明,当采用氩气和水作为推进剂工质,薄膜电阻温度为600K,工作滞止压强为500Pa时,FMMR推进单元的比冲分别为47.900s(1s=9.8N·s/kg)和68.163s,推力为0.158mN,效率为25.8%。通过优化设计、系统集成等可以进一步提高推力器的比冲、推力和效率。
Free molecular micro-resistojet (FMMR) is a novel type of electrothermal microthruster based on micro-electromechanical systems (MEMS) technology. It possesses many advantages, such as high integration, small volume, light weight, fast response, high thrust mass ratio, high reliability, and being easy to integrate thruster array. FMMR has wide application prospect for on-orbit maneuvers on military and civil micro/nanospacecrafts. Various mathematical models are built which include the model of propellant gas molecular interaction with solid surface Cercignani-Lampis-Lord model, variable hard sphere model, and randomly sampled frequency methods. In this study numerical simulation is performed and the characteristics of a typical FMMR thruster predicted by using direct simulation Monte Carlo method incorporating with information preservation method. Using argon as propellant, when the FMMR propulsion unit operating temperature is 600K, and the plenum stagnation pressure is 500Pa, the calculation and analytical result shows that I_(sp)=47.900s(1s=9.8N·s/kg), F=0.158mN and η=25.8% . And under the same conditions, using water as propellant, I_(sp)=68.163s, F=0.158mN and η=25.8%. The performance of FMMR can also be improved through design optimization and system integration.
出处
《固体火箭技术》
EI
CAS
CSCD
北大核心
2004年第3期184-189,共6页
Journal of Solid Rocket Technology
