High-Efficiency Domain Decomposition Method of Hybrid Finite Element-Boundary Integral for Composite Electromagnetic Problems

To accurately and efficiently analyse large-scale and composite electromagnetic problems, an improved complete domain decomposition method (CDDM) of the hybrid finite element-boundary integral (FE-BI) is proposed in this paper. The recently proposed CDDM of FE-UI effectively integrates volume-based nonconformal Schwarz FE-DDM and surface-based nonconformal interior penalty UI-DDM, which has been proved to be flexible and powerful for time-harmonic scattering and radiation problems. To further improve its capability, a new cost-effective additive Schwarz preconditioner is introduced. The new preconditioner is constructed from sparse submatrices which is obtained by rarefying the FE-BI submatrix based on the characteristics of boundary integral equation. Comparing with the previous matrix system, the new preconditioned matrix system consumes less memory and time under the premise of fast convergence. The capability of the improved CDDM of FE-BI is demonstrated by numerical experiments closing to realistic application.