真实气体效应对等离子体鞘套及电磁参数的影响

针对高速飞行器高超声速飞行环境，建立了热化学非平衡流动数值模拟技术，并对计算方法的可靠性进行了验证，接着开展了真实气体效应对飞行器等离子体鞘套及其电磁参数的影响规律分析。结果表明:飞行器物面中心线等离子体密度峰值与飞行试验符合良好；对于碰撞频率，沿滞止流线，双温模型以及Park反应模型对等离子体碰撞频率的影响趋势是一致的；对于相对介电常数，除激波附近，流场其他区域的实部接近1，激波附近小于1，虚部沿滞止流线逐渐升高；双温模型以及Park反应模型对相对介电常数实部和虚部的影响趋势是一致的。      

基于滑动弧的燃烧室头部强化燃烧特性

为了研究基于滑动弧的燃烧室头部强化燃烧效果，探究了燃烧室头部的点火过程以及不同等离子体电源输入功率下的点/熄火边界，利用像增强系统获得了CH*基团的分布云图。实验结果表明：输入功率的增大使得燃烧室的点/熄火边界均得到拓展，与160 W工况相比，输入功率为320 W时，点火边界平均拓宽约17.6%，与未放电相比，输入功率为320 W时，熄火边界平均拓宽约45.3%，滑动弧放电对熄火边界拓宽效果明显；当滑动弧能够点燃来流新鲜混合气时，输入功率的增加使得CH*基团分布向上游移动，当输入功率为320 W时，燃烧火焰驻留在燃烧室头部，当滑动弧激励器仅具有助燃作用时，输入功率的增加使得局部CH*基团辐射强度增强，热释放速率增加。     

基于等离子体磁壳的行星探测器制动机理研究

等离子体磁壳制动技术是一种新型的行星探测器制动手段，具有制动阻力可调、可靠性高、结构质量小等优势，具有潜在的应用前景。开展了等离子体磁壳制动产生方式与工作机理的数值仿真研究。首先，以火星探测器的制动为背景，将等离子体磁壳简化为圆柱构型，建立了等离子体磁壳宏观模型，得到了制动阻力、有效捕获面积和探测器速度随轨道高度的变化关系。随后以等离子体磁壳中离子、电子和次中性粒子之间的相互作用为研究对象，建立了等离子体磁壳微观模型，获得了等离子体粒子数密度和温度随时间变化的规律。微观模型与宏观模型计算出的制动阻力一致，验证了两种模型的有效性。     

长寿命热障涂层的剥落机理及抗剥落结构设计

涂覆于高温合金热端部件表面的热障涂层,具有隔热防护作用,属新一代燃气轮机的关键核心技术。等离子喷涂制备的热障涂层隔热性能好,但长时间高温服役后存在开裂剥落问题,引发基体烧蚀、造成巨大经济损失。因此,发展长寿命热障涂层是该技术领域的重大难题。本文从等离子喷涂热障涂层的独特层状结构特征入手,阐述涂层在高温服役中结构和性能的演变规律,揭示涂层剥落失效机理,总结长寿命热障涂层设计方法。研究表明,等离子喷涂热障涂层呈现以连通2D孔隙为主的层状多孔结构,具有优异的隔热功能和协调应变能力。然而,涂层在高温服役中发生烧结,2D孔隙大量消失,涂层显著刚化,使热障涂层开裂驱动力急剧增加,引发微观裂纹扩展并贯通形成大尺度裂纹,导致涂层最终剥落失效。据此,分别从降低开裂驱动力和增加开裂阻力两方面着手,总结抗开裂新结构涂层设计方法,为研发长寿命热障涂层指明了发展方向。在未来研究中,如何保证涂层高隔热和长寿命并同时兼顾经济性,是发展新一代高性能热障涂层的重点方向。     

临近空间地面模拟装置等离子体源仿真研究

为了指导临近空间地面模拟装置中等离子体源结构设计及等离子体环境参数优化，围绕相关指标体系要求，采用数值模拟方法，分析临近空间等离子体环境地面模拟装置中的射流等离子体与下游目标模拟体相互作用。通过研究射流入口处等离子体状态与下游等离子体对钝体包覆效果的依赖关系，明确了影响包覆特性的关键等离子体参数、重要外控参量，及其对下游目标模拟体包覆特性的影响规律。仿真结果表明：相对于其他因素，射流入口的半径、气体流速、速度偏角、气体温度、钝体直径、环境背压等工况对有效实验区长度及厚度参数的影响较大。相关结果对于临近空间等离子体环境地面模拟装置中等离子体源优化设计及等离子体环境参数定向调控具有指导和借鉴意义。     

Development and coupling test of active spacecraft potential control – Next generation (ASPOC-NG)

The active spacecraft potential control (ASPOC) system developed in the 1990s emits positive ions to neutralise the spacecraft potential, such as used in several missions like Geotail, Equator-S, Cluster, Doublestar and MMS. With the experience gained, the next generation of the active spacecraft potential control (ASPOC-NG) instrument has been developed over the last three years. Thereby, three emission technologies were tested including Liquid Metal Ion Source (LMIS), Liquid Metal Electron Source (LMES) and Solid Metal Electron Source (SMES). The development of the emitter module by FOTEC and the corresponding electronics control unit by IWF is presented. Optimisations were carried out with the focus on the reduction of mass and power consumption to comply with the requirements of future scientific missions. Coupling tests of the modules and the electronics control unit were performed including range, accuracy and lifetime tests. Both ASPOC-NG instruments for positive and negative charge compensation and their performance values show excellent results.     

An atmosphere-breathing propulsion system using inductively coupled plasma source

CubeSats have attracted more research interest recently due to their lower cost and shorter production time. A promising technology for CubeSat application is atmosphere-breathing electric propulsion, which can capture the atmospheric particles as propulsion propellant to maintain long-term mission at very low Earth orbit. This paper designs an atmosphere-breathing electric propulsion system for a 3 U CubeSat, which consists of an intake device and an electric thruster based on the inductively coupled plasma. The capture performance of intake device is optimized considering both particles capture efficiency and compression ratio. The plasma source is also analyzed by experiment and simulation. Then, the thrust performance is also estimated when taking into account the intake performance. The results show that it is feasible to use atmosphere-breathing electric propulsion technology for CubeSats to compensate for aerodynamic drag at lower Earth orbit.     

Shocks and instabilities in the partially ionised solar atmosphere

The low solar atmosphere is composed of mostly neutral particles, but the importance of the magnetic field for understanding observed dynamics means that interactions between charged and neutral particles play a very important role in controlling the macroscopic fluid motions. As the exchange of momentum between fluids, essential for the neutral fluid to effectively feel the Lorentz force, is through collisional interactions, the relative timescale of these interactions to the dynamic timescale determines whether a single-fluid model or, when the dynamic frequency is higher, the more detailed two-fluid model is the more appropriate. However, as many MHD phenomena fundamentally contain multi-time-scale processes, even large-scale, long-timescale motions can have an important physical contribution from two-fluid processes. In this review we will focus on two-fluid models, looking in detail at two areas where the multi-time-scale nature of the solar atmosphere means that two-fluid physics can easily develop: shock-waves and instabilities. We then connect these ideas to observations attempting to diagnose two-fluid behaviour in the solar atmosphere, suggesting some ways forward to bring observations and simulations closer together.     

光谱01卫星脉冲等离子推力器电源处理单元的开发

针对光谱01卫星应用需求，提出了脉冲等离子推力器电源处理单元的设计方案，给出了验证结果。采用反激变换拓扑和恒功率方式实现了以2.5Hz的频率将5.76μF的储能电容器充电至1600V，将0.68μF的火花塞点火电容充电至800V；采用超快恢复高压整流管、高压绕组串联、高压整流管串联和开关频率设计解决了反激变换器整流二极管反向恢复引起的功率反向传输问题；采用输出钳位二极管和限流电阻解决了储能电容振荡负电压反向一次母线充电的问题。PPT的地面寿命试验和在轨测试结果表明，所设计的电源处理单元方案合理可行。     

热障涂层在航空发动机涡轮叶片上的应用研究

从热障涂层在涡轮叶片的应用需求出发,研究了陶瓷热障涂层的材料与制备方法,介绍了热障涂层的基本原理和主要工艺特点,解决了热障涂层在喷涂过程中所产生的堵塞气膜孔、减小排气面积、降低疲劳性能、遮挡等方面的难点问题,给出了热障涂层叶片在试验和试车中的考核结果。