离子电喷雾推力器束电流数学模型与敏感性分析  

Mathematical model and sensitivity analysis of beam currentfor ion electrospray thruster

作　　者：雪佳强 郭宁[1] 孟伟[1] 杨三祥 李春波 王墨戈 XUE Jiaqiang;GUO Ning;MENG Wei;YANG Sanxiang;LI Chunbo;WANG Moge(Science and Technology on Vacuum Technology and Physics Laboratory,Lanzhou Institute of Physics,Lanzhou 730000,China;College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073,China)

机构地区：[1]兰州空间技术物理研究所真空技术与物理重点实验室,甘肃兰州730000 [2]国防科技大学空天科学学院,湖南长沙410073

出　　处：《火箭推进》2024年第2期77-87,共11页Journal of Rocket Propulsion

基　　金：国家重点研发计划引力波探测专项(2021YFC2202704)。

摘　　要：虽然阵列式结构的离子电喷雾推力器具有小体积、高比冲、高推力分辨率等优点,但是其发展受到了缺乏理论研究的限制。针对该问题,基于多点发射现象发展了描述推力器束电流的数学模型,并通过智能优化算法对模型中的经验系数进行了辨识,研究了高、低电压下束电流及发射行为存在的不同特征。基于Sobol方法进行了全局敏感性分析,研究了发射体结构的几何参数对束电流的影响程度。模型计算结果与试验结果基本一致,当电压大于1.5 kV时,发射点基底半径与多孔储层孔隙半径相当,外加电场主要影响束电流的非线性增加;电压小于1.5 kV时,发射点数量较少,基底半径是多孔储层孔隙半径的1.5倍,发射点数量是影响束电流大小的关键因素。敏感性分析结果表明,发射体尖端与提取极之间的距离对束电流的影响程度最大,其1阶敏感性指数为0.841,在加工制造中须严格控制其公差大小。Although the ion electrospray thruster with an array emitter has advantages such as small volume,high specific impulse,and high thrust resolution,its development has been limited by the lack of theoretical researches.To address this issue,a mathematical model describing the beam current of the thruster based on the multi-site emission phenomenon was developed,and the empirical coefficients in the model were identified using intelligent optimization algorithms.The different characteristics of the beam current and emission behavior under high and low voltages were studied.Global sensitivity analysis based on the Sobol method was conducted to investigate the impact of geometric parameters of the emitter structure on the beam current.The model calculation results are basically consistent with the experimental data.When the voltage is greater than 1.5 kV,the base radius of the emission site is equivalent to the pore radius of the porous reservoir,and the external electric field mainly affects the nonlinear increase of the beam current.When the voltage is less than 1.5 kV,the number of emission sites is small,the base radius is 1.5 times the pore radius of the porous reservoir,and the number of emission sites is a key factor affecting the size of the beam current.The sensitivity analysis results show that the distance between the tip of the emitter and the extractor has the greatest impact on the beam current,with a first order sensitivity index of 0.841,and its tolerance must be strictly controlled in manufacturing processes.

关 键 词：纯离子状态 多点发射 束电流预测 数学模型 Sobol敏感性分析 

分 类 号：V439[航空宇航科学与技术—航空宇航推进理论与工程]