A Hybrid Iterative-Direct Solver Based on Fast Multipole Method for Efficient Finite Element-Boundary Element Coupling Analysis

The coupling of FEM-BEM in electromagnetic modeling can be beneficial for problems involving open boundary or motion, or more general for problems with complex geometry. However, its efficiency is limited because of the dense block introduced by the BEM discretization. In this work, a hybrid iterative-direct solver based on fast multipole method is proposed and implemented for efficient FEM-BEM coupling to accelerate the computational procedure. The computational time and memory usage can be reduced to linear complexity with the proposed approach.