超声速气流电容耦合射频放电特性

Characteristic of Capacitive Coupled Radio-frequency Discharge in Supersonic Flow

针对如何产生均匀和稳定的超声速非平衡等离子体这一科学问题,为进一步探究超声速气流电容耦合射频放电特性,建立了超声速非平衡电离磁流体动力技术实验系统,开展了Ma=3.4条件下,超声速气流边界层与主流中心区的电容耦合射频放电特性研究;同时针对超声速放电等离子体的实时诊断问题,基于均匀射频放电模型,联立能量平衡方程,建立等离子体诊断模型对平均电子数密度与电子温度等参数进行诊断。结果表明:超声速气流条件下,通过电容耦合射频可以产生均匀和稳定的放电等离子体;分子数密度是影响超声速气流放电特性的主要因素,同时超声速气流对平均电子温度的影响很小,约为0.46 e V。

Aiming at the scientific problem of how to produce the uniform and stable supersonic flow non-equilibrium plasma, and in order to further explore the characteristics of capacitively coupled radio-frequency（CCRF） discharge in supersonic flow, we established a supersonic non-equilibrium ionization MHD technology experiment system to experimentally research the CCRF discharge characteristics for the main flow and boundary region in Ma=3.4 supersonic flow.Moreover, aiming at the problem of real-time diagnosis of supersonic plasma, we established a diagnostic model based on the homogeneous radio-frequency discharge model coupling with power balance equation to diagnose the mean electron number density and electron temperature. The result shows that the uniform and stable plasma can be produced in the supersonic flow by CCRF; the number density of molecules is the main influential factor of characteristic of discharge in supersonic flow, and the supersonic flow has slight effect on the mean electron temperature and is approximately 0.46 e V.