基于PML的FDTD法正演模拟

Forward Modeling of FDTD Method on PML

自首次提出时域有限差分法以来,其应用价值备受关注。FDTD法的核心问题是边界条件的设置。采用完全匹配层作为FDTD法的吸收边界条件,首先简介了一般Maxwell方程及FDTD法的基本原理,然后详细推导了二维TM波在PML条件下的麦克斯韦方程组,最后利用Matlab软件对高斯脉冲波在一维情况下的PML进行正演模拟以及二维TM波在PML吸收层中的传播情况进行正演模拟。结果表明:模型中所设置的PML吸收边界条件对边界处的电磁波吸收效果比较好。

Since the finite difference in time domain(FDTD)method is proposed firstly,the value of the application has attracted much attention.The core problem of FDTD is the setting of boundary conditions.In this paper,the perfectly-matched layer(PML)is used as the absorption boundary condition of FDTD method.Firstly,the general Maxwell equation and the basic principle of FDTD method are introduced.Then,Maxwell equations of 2D TM wave under PML condition are deduced in detail.Finally,the forward modeling of the Gaussian pulse wave in one-dimensional case is simulated by Matlab software.The propagation of two-dimensional TM wave in PML absorption layer is simulated by forward modeling.The results show that the absorption boundary conditions of PML in the model are better for the electromagnetic wave absorption at the boundary.