On the non-conformal domain decomposition algorithms of FE-BI-MLFMA for 3-D electromagnetic scattering and radiation problems

The non-conformal domain decomposition algorithms of the hybrid finite element-boundary integral-multilevel fast multipole algorithm are presented for computing large electromagnetic scattering and radiation problems. The numerical performance of different transmission conditions between finite element method (FEM) subdomains, and FEM and boundary integral (BI) domains is studied in the paper. It is found that the Dirichlet transmission condition employed on the interface between FEM and BI domains has faster convergence than the Robin-type transmission condition. Furthermore, the cement-element-based dual-primal finite element tearing and interconnecting (FETI-DP) domain decomposition method has faster convergence than the Lagrange-multiplier-based FETI-DP method under the FE-BI system.