Research On The Parallel Computing Of Extremely Large-Scale Targets’s Scattering Characteristics And Related Problems

With higher frequencies applied in practial engineering application, large-scale and extremely large-scale targets analysis becomes more and more important in the field of computational electromagnetic. As a fast algorithm for solving scattering and radiation probelms, Multilevel Fast Multipole Algorithm has become important means and hot focus during its low computational complexit and high accuracy. This paper focuses on inter-node parallelisms based on MPI and intra-node parallelisms based on OpenMP in Multilevel Fast Multipole Algorithm. Meanwhile higher-order basis functions can keep good error convergence rate and maintain the virtue of high accuracy with less unknowns and less memory requirement compared with low-order basis functions, so we introduce them to MLFMA parallelisms in order to solve larger scale targets in the same computer platform compared with other basis functions. The scattering character-stic analysis of targets consisting of dielectric and metal section is essential for military invisible research, and VSIE is a available numerical method on the basis of Method of Moments to solving this situation, the paper also combines VSIE and MLFMA paralle-lisms aimed at the scattering and radiation probelms research in a batter platform.Firstly, the pivotal techniques of basic method-Method of Moments (MoM), which MLFMA is applied to, are introduced, and the hardware architecture and software envi-ronment follow. MPI-OpenMP programming mode and the evaluation criteria of parallel efficiency are described in detail.Secondly, MLFMA, accelerating matrix vector multiplication in solving the integral equation, is discussed detailed. During the program development of parallel algorithms, from judging basis functions to establishing multi model, and from the calculation of the near-field interaction and transfer factor to the final moments of matrix vector multiplication, and so on, everyone is be effectively analysed. A lot of effective work are done in order to obtain efficient computing speed and adequate parallelism, such as the hybrid parallelization based on MPI and OpenMP is used to judging the basis functions, transfer factor is calculated separately for the difference between the upper level and the lower level compared with the transition level, and preparation working for efficient iterative solution, and so on.Moreover, using curvilinear triangular patch to describe the surface of scattering target, this paper successfully combines the new travelling standing wave basis functions and MLFMA parallelisms. We achieve an effective analysis for scattering properties of large-scale and extremely large-scale targets.Finally, as the characteristics of scattering from the hybrid structure containing metal and dielectric materials is always a problem concerned and explored by scholars, this paper successfully combines method of moments based on the hybrid integral equations and MLFMA parallelisms. The scattering problem of the hybrid structure gets an efficient solving method.