节点文献
电弧加热发动机的设计与研究
Design and Study on Arcjet
【作者】 陈黎明;
【作者基本信息】 清华大学 , 工程热物理, 2002, 博士
【摘要】 星上推进系统是为航天器提供机动和控制推力的装置。目前,电推进系统以其优越的性能逐步取代传统的化学推进系统,被广泛的用于空间飞行任务。作为电推进的一种方式,电弧加热发动机以较高的推力/功率比、推力密度、中高的比冲、良好的系统继承性和可靠性等特点,成为当前国际研究和应用的热点。随着空间技术的发展和未来航天任务的需求,先进的电弧加热发动机将是理想的选择。因此,开展对电弧加热发动机的研究具有十分重要的意义。本文设计、建造一套性能先进的低功率电弧加热发动机。详细讨论了发动机对不同组件的性能要求,并根据要求对每一个构件选择了合适的材料,使其稳定可靠工作。本文通过优化发动机其内部结构,减小了热损失,提高了比冲。本文设计、建立了一套满足真空度要求的真空模拟系统和电弧加热发动机性能测量系统,并对电弧加热发动机进行实验研究和性能测试。以氩气作为推进剂,在不同工况下进行点火实验,测量获得了其工作推力、电弧电压和电流、推进剂流率和弧室压力等宏观参数,得到了不同实验条件下其工作的实际比冲、推力效率、推力/功率比以及比功率等性能参数,分析了推进剂质量流率、电弧功率、电弧加热发动机电弧室结构尺寸等因素对其性能的影响,为数值模拟研究和实际的低功率电弧加热发动机优化设计及研制提供了实验基础。本文优化并改进了一套高速、高精度的多谱线电弧等离子体光谱诊断系统,使其适用于电弧加热发动机羽流激发温度的诊断,并利用该系统诊断了发动机出口羽流的非平衡程度和温度沿径向的分布。本文还研究了发动机运行参数,如电流、流量对羽流平衡态和温度分布的影响。本文建立了电弧加热发动机工作的简化的一维理论分析模型。该模型实现了快速、有效地预报了电弧加热发动机的性能,有助于分析实验结果和理解发动机内部电弧复杂的物理过程,为其实际应用到我国空间任务提供了理论基础。
【Abstract】 The propulsion system is used to provide impetus for motion and control of spacecraft. At present, electric propulsion system has been widely applied in space fight missions and ascendant performance of electric propulsion makes it a substitution of traditional chemical propulsion system gradually. Arcjet is one of the highlight of electric propulsion investigation and application because of its high thrust density, high ratio of thrust and power, preferable specific impulse, better system successiveness and reliability. Advanced Arcjet system will be one of the favorite choices with the development of space technology and the demand of aerospace task. So it has important significance to investigate the Arcjet system.A low power Arcjet with high performance has been designed and constructed in this dissertation. This Arcjet can run steadily with high temperature status and in low-pressure environment. Detailed requirements are discussed for every component of the Arcjet. According to the specific requirement for every component, suitable material is selected for it. The internal structure has been optimized to reduce the heat loss and increase the specific impulse.Much works has been distributed to the development of a vacuum system to simulate the outer space and a measurement system to test the Arcjet performance. Ignition experiments in various operational modes have been done with Argon as propellant. Macroscopical working parameters including thrust, mass flow rate, voltage, current, inlet pressure and vacuity are obtained by the test measurement system and actual performance parameters including specific impulse, thrust efficiency, ratio of thrust and power and ratio of power and mass flow are calculated. The influence of parameters such as mass flow, input power, and constrictor size on Arcjet performance is also analyzed. This work provides an experimental foundation for the numerical simulation study and optimized design of Arcjet.A high-speed, high-resolution, multi-line spectroscopic diagnostic system has been improved to diagnostic the excitation temperature of Arcjet plume. The extent of
【Key words】 Arcjet; Plasma; Plume; Diagnostics; Numerical simulation;