等离子体时域有限差分方法及再入等离子体涂覆目标电磁特性研究

发布时间：2019-06-10 17:42

【摘要】：本文研究了等离子体媒介时域有限差分方法;给出了梯形递归卷积时域有限差分数值计算方法(TRC-FDTD)在磁化、非磁化情况下详细的推导过程;对再入飞行器进行建模;分析了再入等离子体媒介涂覆典型目标以及再入钝锥体的电磁特性。论文的主要工作如下:1.利用麦克斯韦方程组及相关方程,结合梯形递归卷积理论,以及Yee提出的离散处理的办法,给出了非磁化等离子体媒介中的梯形递归卷积时域有限差分数值计算方法(TRC-FDTD)详细的推导过程;通过相应的算例,校验了方法的正确性及有效性。2.研究了磁化等离子体梯形递归卷积时域有限差分数值计算方法(TRC-FDTD);研究了不同入射角入射的极化电磁波与磁化冷等离子体彼此之间的作用;当电磁波传播方向平行于磁场方向时,分别计算了左旋极化波以及右旋极化波的相关电磁特性参数,在一定频率域内,入射角增大,反射系数增大;当电磁波的传播方向与磁场方向互相垂直时,对非寻常波以及寻常波进行了分析讨论同时也讨论了截止频率。3.建立了再入飞行体钝锥体模型,利用计算流体力学得到再入等离子体流场。通过TRC-FDTD算法,讨论了电磁波通过再入等离子体平板中的电磁特性;分析了参考点位置、再入速度、再入高度、等离子体涂层厚度等参数对电磁散射特性的影响;研究了磁化与非磁化情况再入体等离子体媒介涂覆不同形状的典型目标以及再入钝锥体的雷达散射截面(RCS),讨论了参考点位置、再入速度、再入高度、回旋频率、等离子体涂层厚度等参数变化产生的影响,发现不同参数的变化对不同目标的RCS变化影响很大。
[Abstract]:In this paper, the finite difference time domain method of plasma medium is studied, the finite difference time domain numerical method of ladder recurrent convolution (TRC-FDTD) is deduced in detail under the condition of magnetization and unmagnetization, and the reentry vehicle is modeled. The electromagnetic characteristics of typical targets coated with reentry plasma medium and reentry obtuse cone are analyzed. The main work of this paper is as follows: 1. By using Maxwell equations and related equations, combined with the theory of ladder recurrent convolution, and the method of discrete processing proposed by Yee, The finite difference time domain method (TRC-FDTD) of ladder recurrent convolution in unmagnetized plasma media is deduced in detail. The correctness and effectiveness of the method are verified by the corresponding examples. 2. The finite difference time domain method (TRC-FDTD) of magnetized plasma ladder Recursive convolution is studied, and the interaction between polarized electromagnetic wave and magnetized cold plasma with different incident angle is studied. When the propagation direction of electromagnetic wave is parallel to the direction of magnetic field, the related electromagnetic characteristic parameters of left-handed polarization wave and right-handed polarization wave are calculated respectively. in a certain frequency domain, the incident angle increases and the reflection coefficient increases. When the propagation direction of electromagnetic wave is perpendicular to the direction of magnetic field, the unusual waves and ordinary waves are analyzed and discussed, and the cutoff frequency is also discussed. The blunt cone model of reentry flight body is established, and the reentry plasma flow field is obtained by computational fluid dynamics (CFD). Through TRC-FDTD algorithm, the electromagnetic characteristics of electromagnetic wave passing through the reentry plasma plate are discussed, and the effects of reference point position, reentry velocity, reentry height and plasma coating thickness on the electromagnetic scattering characteristics are analyzed. The typical targets with different shapes coated with magnetized and unmagnetized reentry plasma media and the radar cross section (RCS), of reentry obtuse cone are studied. the position of reference point, reentry velocity, reentry height and cyclotron frequency are discussed. It is found that the change of RCS of different targets is greatly affected by the change of plasma coating thickness and other parameters.
【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN011

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