Computation of scattering by large inhomogeneous targets using hybrid h- and p-Type multiplicative Schwarz (h-p-MUS) preconditioned FE-BI-MLMFA

The scattering by inhomogeneous targets is computed by a hybrid h- and p-Type multiplicative Schwarz (h-p-MUS) preconditioned finite element-boundary integral-multilevel fast multipole algorithm (FE-BI-MLFMA). In the h-p-MUS preconditioner, the hierarchical higher-order FEM matrix is first rewritten by classifying unknowns into different groups corresponding to different FEM orders. Then a preconditioner is constructed by the p-type multiplicative Schwarz method (p-MUS). To speed the p-MUS construction, an h-type multiplicative Schwarz preconditioner is employed for different submatrices. Numerical results show that the scattering by large and complex inhomogeneous targets can be accurately and efficiently computed by this h-p-MUS preconditioned FE-BI-MLFMA.