基于传输矩阵法的等离子体鞘套传输特性分析

引入分层模型传输矩阵法，分析高速临近空间飞行器等离子体鞘套传输特性.通过对典型飞行器模型进行纳维-斯托克斯方程组数值求解，仿真了等离子体鞘套的流场电子密度分布，分析了电磁波在等离子体鞘套内传输时的衰减常数，给出信号传输的反射系数和透射系数.基于传输矩阵法的仿真结果与理论分析结果和时域有限差分法仿真分析结果有良好的一致性，同时，该方法有效降低了计算复杂度，适用于任意电子密度分布和厚度的等离子体鞘套传输特性的数值求解.

Study on the transmission properties of plasma sheath based on transfer matrix method

Due to compression and pyrogenation by shock wave, plasma sheath is formed around the surface of vehicle when hypersonic aerocrafts fly in near space. Plasma sheath can absorb and reflect electromagnetic wave radiated by the antenna on the vehicle. In order to analyze transmission property of plasma sheath, transfer matrix method is introduced. Based on the typical vehicle model and fundamentals of computational fluid dynamic, the Navier-Stokes equations are solved and electron density distribution in the plasma sheath is obtained. On the basis of propagation theory of electromagnetic wave and correlative characteristics of plasma sheath, the attenuation coefficient of electromagnetic wave in plasma sheath is diagnosed. On the other hand, propagation characteristics of electromagnetic signals which mainly include refection and transmission coefficients are analyzed. Analysis results show that good agreement is achieved among numerical results of transfer matrix method, theory analysis results and simulation results of FDTD (Finite Difference Time Domain). It is proved that the proposed method dramatically decreases computation complexity and is suitable for any kind of electron density distribution and thickness of plasma sheath.