一种使用八叉树的半空间MLFMA区域分解算法  

Algorithm for half-space MLFMA domain decomposition utilizing an octree

作　　者：翟畅[1] 林中朝[1] 赵勋旺[1] 张玉[1] ZHAI Chang;LIN Zhongchao;ZHAO Xunwang;ZHANG Yu(Shaanxi Key Laboratory of Large Scale Electromagnetic Computing,Xidian University,Xi’an 710071,China)

机构地区：[1]西安电子科技大学陕西省超大规模电磁计算重点实验室,陕西西安710071

出　　处：《西安电子科技大学学报》2021年第6期144-150,共7页Journal of Xidian University

基　　金：国家自然科学基金(61901323);国家重点研发计划(2017YFB0202102);中央高校基本科研业务费专项资金(XJS190210);济南市高校20条项目(2018GXRC015)。

摘　　要：为了在有限资源的情况下快速准确地分析半空间电大目标的电磁散射特性,提出一种使用八叉树结构的并行半空间多层快速多极子区域分解算法。通过利用多层快速多极子算法在空间中形成的八叉树结构,自适应地对未知量进行分组来实现区域的划分,从而避免了在区域之间创建虚拟交界面,降低了模型的处理工作量。为保证区域间电流的连续性,在边界处严格计算1/4阻抗,使结果更加精确。对于半空间环境,引入复镜像源来计算半空间近相互作用,并且引入实镜像源来计算半空间远相互作用。通过与商业软件FEKO整体解对比分析,证明了算法的可靠性和精确性。采用核外算法将转移因子等复用数据存储在硬盘中,并与整体解资源消耗进行对比,证明这种算法能有效地减少内存消耗。最后,给出一个千波长半空间舰船区域分解算例,证明所提出的算法能够在有限的计算资源情况下仿真电大尺寸模型。In order to quickly and accurately analyze the electromagnetic scattering of electrical large objects in half space under the condition of limited resources,a parallel half-space multi level fast multipole algorithm(MLFMA)with the domain decomposition method utilizing an octree is proposed.By using the octree structure formed by the MLFMA,the unknowns are grouped adaptively to realize the domain decomposition,thereby avoiding the creation of artificial interface between domains and reducing the workload of model processing.To ensure the current continuity between domains,the 1/4 impedance on the boundary of the domain is rigorously calculated,with the results more accurate.To deal with the half-space environment,the complex image source is introduced to calculate the near interaction,and the real image source is introduced to calculate the far interaction.A comparison of numerical results from the proposed algorithm and the commercial software FEKO is given,which proves the reliability and accuracy of the algorithm.An out-of-core algorithm is used to store data such as translators in the hard disk,which can significantly reduce the memory consumption.Finally,a numerical example including a 1000-wavelength ship model in half space is given,which demonstrates that the proposed algorithm can simulate electrical large objects under the condition of limited resources.

关 键 词：区域分解 并行计算 多层快速多极子 半空间问题 八叉树策略 核外算法 

分 类 号：TN820[电子电信—信息与通信工程]