脉冲等离子体推力器特氟隆烧蚀过程数值模拟

电弧推力器约束通道内流动特性数值模拟魏福智;何艳;耿金越【摘要】约束通道对电弧推力器的性能有着重要的影响,文章采用基于局域热力学模型(LTE)的数值模拟方法对中等功率电弧推力器内等离子体流动进行了数值模拟,考察了电流、入口压力、约束通道尺寸及不同推进剂对约束通道内等离子体流动的影响,分析了约束通道内非均匀流动现象,最后对推力器的性能、效率等进行了讨论.计算结果表明,随着电流的增加电弧高温区变粗变长,随着入口压强的增加电弧高温区半径减小而长度增加,随着约束通道半径的减小电弧高温区变得细长,随着约束通道长度的增加高温区的长度增长而半径无明显变化,氢气的高温区明显小于氮气和氩气;约束通道内只有小部分气体通过高温区被电离,大部分气体沿着壁面附近的低温区流动;约束通道内焦耳热约占总焦耳热的60%~80%,主要受约束通道长度影响.%The constrictor is a key part of arcjet thrusters,which has a significant effect on the performance and efficiency of the arcjet thruster.A modeling study was performed to investigate the plasma flow through the constrictor of medium power arcjet thrusters based on the local thermal equilibrium (LTE ) assumption. The effects of the current, inlet pressure,constrictor dimensions and different propellants on the plasma flow characteristics, including the nonuniform flow characteristics,within the arcjet constrictor were studied.And the effects of the current,inlet pressure and constrictor dimensions on the performance and efficiency were further presented.The numerical results show that the hot arc region radius and length increase with the increase of the current;with the increase of the inlet pressure,the radius of hot arc region decreases butlength increases;with the decrease of the constrictor radius,the hot arc region radius decreases while length increases;the hot arc region length increases and radius shows no significant changes with the increase of the constrictor length;and the hot arc region with hydrogen as the propellant is apparently smaller than those with nitrogen and argon as the propellant. It is also found that a small amount of the gas passes through the hot arc region where the gas is ionized,and most of the gas flows through the low temperature region near the wall.The Joule heating within the constrictor approximately accounts for 60%-80% of the total Joule heating within the arcjet thruster,mainly affected by the constrictor length.【期刊名称】《中国空间科学技术》【年(卷),期】2016(036)001【总页数】8页(P43-50)【关键词】电弧推力器;数值模拟;约束通道;等离子体;流动【作者】魏福智;何艳;耿金越【作者单位】北京控制工程研究所,北京 100190;中国空间技术研究院通信卫星事业部,北京 100094;北京控制工程研究所,北京 100190【正文语种】中文【中图分类】V439+.4作为电弧推力器的关键组成部分,约束通道一般为等截面直管,连接压缩段和喷管扩张段。

等离子体推动器一、为什么要使用电推动器？1.传统化学推进剂的缺点：〔a〕在深空探测中，化学推进剂占航天器重量的绝大局部，有效载荷小，效率低，造价高。

－〔附：肼〔联氨〕-----一种无色发烟的、具有腐蚀性和强复原性的液体化合物NH2 NH[hydrazine],它是比氨弱的碱,通常由水合肼脱水制得,燃烧热较大主要用作火箭和2喷气发动机的燃料,用在制备盐(如硫酸盐)及有机衍生物中〕在探索更远的星球时，化学燃料推动已不可行。

〔b〕通信卫星长寿命增加〔15 年〕,为保持轨道定点位置,所需的推进剂越来越多〔使用次数愈来愈多〕,大量挤占了有效载荷的重量。

因此,大型通信卫星的推进系统改用电推进已势在必行。

目前航天领域广泛使用的化学火箭发动机，对于完成航天器从地面向空间轨道的发射任务，还难以用其它动力装置代替。

但由于化学推进的比冲偏小，最大不超过4.6kN*s/kg，所以，如果对于航天器的轨道转移、轨道修正、姿态控制、对接交会、位置保持、南北轨控和星际航行等特殊任务仍然采用化学动力装置，那么就会使一直昂贵的航天器发射本钱居高不下，而且也会严重影响其使用寿命。

2.电推进器的优缺点优点：〔a〕效率高―――喷射离子速度远高于化学燃烧气体粒子速度；电推进技术的推进剂效率(或比冲) 是化学推进系统的几倍甚至几十倍〔b〕所需重量降低；〔c〕最终速度高〔化学推进剂： 5 km/s，电推动：10-20 km/s〕。

缺点：推力小，加速时间长，需要电源，二、推进器的任务✹轨道转移；✹遥感卫星的轨道调整和姿态控制；✹通讯卫星的轨道保持；✹深空探测；三、电推进简史1．国际电推动开展史☞第一次离子推动实验室实验By 1916 Goddard and his students were conducting perhaps the world's first electric propulsion experiments with ion sources. Four years later Goddard devoted passages of his technical reports to his EP experiments.☞第一次电推动飞行实验世界上首次电推进(脉冲等离子体推进) 空间飞行试验是前苏联于1962 年进展的；〔该次发射的意义：标志科学界已承受电推进技术，进入一个新的历史时期：不再是证明电推进是否有价值的时期，而是解决静电推进存在的问题。

两种激光烧蚀微推力器工作模式的讨论叶继飞;李南雷;常浩【摘要】The laser ablation micro-thruster technology is one of the most promising technologies to realize the engineering application of laser propulsion technology. As a new kind of electric propul-sion thruster technology in the field of space propulsion, it has high degree of system integration, low power consumption, precision impulse element and other characteristics, forms a vivid feature in the aspects of propulsion performance and system integration, and possesses a potential application value for a variety of space missions. In this paper, the development trend of laser ablation micro-thruster technology is summarized by taking development history of laser ablation micro-thruster as the back-ground, two working modes of the laser ablation micro-thruster, which have highest research value at present, are put forward, and the performances of the two working modes with high specific impulse and low specific impulse are analyzed respectively. Application prospect of the laser ablation micro-thruster is prospected. Finally, some suggestions for further research are given.%激光烧蚀微推力器技术是激光推进技术最有可能率先实现工程应用的技术研究方向.作为一种新型的空间推进领域电推进推力器技术,以其系统集成度较高、电功耗较低、冲量元精准等优势特性,在推进性能和系统集成等方面形成鲜明的特色,对于多种空间推进任务具备潜在的应用价值.以激光烧蚀微推力器发展历程为背景,总结提炼当前推力器技术发展趋势,提出了激光烧蚀微推力器目前最具研究价值的两种工作模式,分别对高低比冲两种不同工作模式进行了性能分析和比对,对激光烧蚀微推力器应用前景进行了展望,最后给出了进一步研究的建议.【期刊名称】《火箭推进》【年(卷),期】2017(043)005【总页数】7页(P7-13)【关键词】激光推进;推力器;冲量耦合;激光烧蚀微推力器【作者】叶继飞;李南雷;常浩【作者单位】装备学院激光推进及其应用国家重点实验室,北京101416;装备学院激光推进及其应用国家重点实验室,北京101416;装备学院激光推进及其应用国家重点实验室,北京101416【正文语种】中文【中图分类】V439-34经过近50年的发展，激光推进技术做为一种新概念航空宇航推进技术，在理论论证、实验演示和数值模拟等方面都取得了令人瞩目的进展。