Non-conformal DDM-FEM-BI with Gauss-Seidel preconditioner for scattering from coating objects

A non-overlapping and non-conformal domain decomposition method (DDM) is presented for solving scattering from coating objects. This method decomposes the original problem into several non-overlapping sub-domains and adopting the finite element tearing and interconnecting like algorithm for electromagnetic problems. The 1st-order transmission condition is employed on interfaces between adjacent sub-domains to enforce the continuity of electromagnetic fields and ensure the well-posed property of sub-domain problems. The final system matrix is symmetrical and solved by Krylov solvers that is equipped with a Gauss-Seidel preconditioner. Numerical results are shown to demonstrate the accuracy and efficiency of the proposed method.