一种快速计算多柱体散射问题的区域分解时域有限差分方法  

A Novel Domain Decomposition FDTD Algorithm (DD-FDTD) for the Analysis of Multi - Cylinders Scattering Problem

作　　者：许锋[1] 洪伟[1] 丁振宇[1] 

机构地区：[1]东南大学国家毫米波重点实验室,江苏南京210096

出　　处：《电子学报》2002年第9期1327-1329,共3页Acta Electronica Sinica

基　　金：国家杰出青年资金(No.69925102)

摘　　要：本文提出一种用于计算多柱体散射问题的区域分解时域有限差分算法（DD-FDTD）.当各散射柱体相互间距离比较远时,采用经典的FDTD方法进行计算时,计算域是非常大的,大量的网格浪费在散射体之间.文中我们使用区域分解的思想,把各个柱体处理为各个子域.各柱体间大量的网格被省去,代之以二维时域Green函数将各个子域连接起来.采用近远场变换方法,并将柱体间互偶处理为等效柱面波人射场,从而大大压缩了计算时间.由于二维时域Geen函数含有关于时间的积分,且此积分是一个反常积分,采用半解析的方法,精确地算出了其中的反常积分值,大幅度提高了计算精度.最终.使该方法得以实现。A novel domain decomposition FDTD method (DD-FDTD) is presented for solving multi-cylinder scattering problem. When the distances between cylinders are rather far, the computational domain of classical FDTD is very large. The idea of domain decomposition is introduced here for greatly decreasing the computational time. Based on this idea,the original domain is decomposed into several sub-domains according to each cylinder. All of sub-domains are connected by use of the 2-D time domain Green s function. However,the integral for time is included in the 2-D time domain Green s function,and it is an abnormal integral. In this article, by means of quantifying the positions of equivalent sources and arranging the time series, the calculations of the time integrals of equivalent sources are converted to the calculation of matrix multiplying. Besides, by using the analytic method, the abnormal integral for the time is obtained exactly. Several 2-D scattering problems are calculated by using this method and the accuracy of the solution validates the usefulness and exactness of this method.

关 键 词：区域分解 时域有限差分法 二维时域Green函数 多柱体散射 DD-FDTD 

分 类 号：TN011[电子电信—物理电子学]