An IE-ODDM-MLFMA Scheme With DILU Preconditioner for Analysis of Electromagnetic Scattering From Large Complex Objects
An IE-ODDM-MLFMA Scheme With DILU Preconditioner for Analysis of Electromagnetic Scattering From Large Complex Objects
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DOI：
10.1109/tap.2008.922608
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发表时间：
2008-05
影响因子：
5.7
通讯作者：
Weidong Li;W. Hong;Houxing Zhou
中科院分区：
文献类型：
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作者：
Weidong Li;W. Hong;Houxing Zhou
对于电大尺寸的复杂电磁散射问题，大多数电磁场求解器都需要占用大量的内存，这对于个人计算机甚至工作站来说都是非常困难的。虽然多层快速多极子算法（MLFMA）在一定程度上有效地处理电大尺寸问题，但它仍然是非常大的对象消耗时间和内存。为了进一步减少CPU时间和内存需求，提出了一种基于积分方程重叠区域分解法（IE-OFDM）、多层快速移动法（MLFMA）和块对角不完全上下三角矩阵（DILU）预条件子的混合算法，用于电大尺寸问题的分析.前两种技术大大减少了MLFMA中聚合、平移和解聚合三个过程中平面波展开的主要内存需求。DILU预处理器有效地加快了MLFMA求解每个重叠子域的迭代过程。在集成这些技术后，所提出的混合算法是更有效的计算时间和内存需求相比，传统的MLFMA，更适合于分析非常大的电磁散射问题。在相当多的外部迭代内可以获得足够精确的解，其中外部迭代意味着对所有子域的完全扫描。数值算例验证了该方法的有效性。
For electrically large complex electromagnetic (EM) scattering problems, huge memory is often required for most EM solvers, which is too difficult to be handled by a personal computer (PC) even a workstation. Although the multilevel fast multipole algorithm (MLFMA) effectively deals with electrically large problems to some extent, it is still time and memory consuming for very large objects. In order to further reduce the CPU time and the memory requirement, a hybrid algorithm, based on the overlapped domain decomposition method for integral equations (IE-ODDM), MLFMA and block-diagonal, incomplete lower and upper triangular matrices (DILU) preconditioner, is proposed for the analysis of electrically large problems. The dominant memory requirement for plane wave expansions in the three processes of aggregation, translation and disaggregation in the MLFMA is drastically reduced by the first two techniques. The iterative procedure for each overlapped subdomain solved by the MLFMA is effectively sped up by the DILU preconditioner. After integrating these techniques, the proposed hybrid algorithm is more efficient in computing time and memory requirement compared to the conventional MLFMA and is more suitable for analyzing very large EM scattering problems. Enough accurate solution can be obtained within quite a few outer iterations, where an outer iteration means a complete sweep for all the subdomains. Some numerical examples are presented to demonstrate its validity and efficiency.