FDTD ALGORITHM IN CURVILINEAR COORDINATES
FDTD ALGORITHM IN CURVILINEAR COORDINATES
复制标题
DOI：
10.1109/8.43592
复制
发表时间：
1990-01-01
影响因子：
5.7
通讯作者：
FUSCO, M
中科院分区：
文献类型：
--
作者：
FUSCO, M
用于解决电磁散射问题的时域有限差分 (FDTD) 算法在二维广义坐标中表述，并在具有以柱坐标表示的最低阶 Bayliss-Turkel 辐射边界条件的代码中实现。结果表明，对于完美导体，这样的公式会产生稳定的适定算法，并且在坐标线曲率不大的区域中，色散和各向异性效应可以忽略不计。这种效应在高曲率区域变得更加明显，导致非物理相移。使用圆柱网格通过数值实验研究这种偏移的幅度和波前畸变的量。给出了每种偏振的两种典型形状的近场结果：圆柱体以及方形和矩形横截面的圆柱体。将这些结果与通过精确特征函数展开技术、矩量法 (MM) 解决方案以及通过替代 FDTD 方法获得的解决方案进行比较。在每种情况下，一致性都非常好。还研究了在没有散射体的情况下平面波通过极地空间的传播，结果表明 FDTD 算法能够紧密跟踪入射波。<>
The finite-difference-time-domain (FDTD) algorithm for the solution of electromagnetic scattering problems is formulated in generalized coordinates in two dimensions and implemented in a code with the lowest-order Bayliss-Turkel radiation boundary condition expressed in cylindrical coordinates. It is shown that, for a perfect conductor, such a formulation leads to a stable, well-posed algorithm and that, in regions where the curvature of the coordinate lines is not great, the dispersion and anisotropy effects are negligible. Such effects become more pronounced in regions of high curvature, leading to unphysical phase shifts. The magnitude of such shifts and the amount of wavefront distortion is studied via numerical experiments using a cylindrical mesh. Near-field results are given for two canonical shapes for each polarization: the circular cylinder and cylinders of square and rectangular cross sections. These results are compared with those obtained by exact eigenfunction expansion techniques, with method-of-moments (MM) solutions, and with solutions obtained from an alternate FDTD approach. In each case, agreement is excellent. The propagation of a plane wave through a polar space in the absence of a scatterer is also examined, and it is shown that the FDTD algorithm is capable of tracking the incident wave closely.<>