A Novel Finite Element Mesh Truncation Technology Accelerated by Parallel Multilevel Fast Multipole Algorithm and its Applications

Abstract

In order to meet the highly accurate requirements of nowadays scattering and antenna problems, the finite element method requires the use of very accurate mesh truncations techniques able to absorb any outgoing wave completely. In this paper a novel implementation of the finite element mesh truncation technique called Finite Element-Iterative Integral Equation Evaluation (FE-IIEE) is studied. This method can provide a numerical exact radiation boundary condition while the original sparse and banded structure of the finite element method (FEM) matrix is retained. Also, an efficient parallel multilevel fast multipole algorithm (MLFMA) is included to drastically accelerate the time-consuming near field calculation process required by the truncation technique. In order to achieve a high parallel efficiency, both algorithms have been implemented together from scratch, being able to run over several thousands of CPU cores. Through comparisons with commercial software such as HFSS, the accuracy and efficiency of the method are validated showing excellent performance. Finally, a large 100- elements array antenna with more than 24 million unknowns is effectively analyzed using 2560 CPU cores.