Efficient solution of the combined-field integral equation with the parallel multilevel fast multipole algorithm

We present fast and accurate solutions of large-scale scattering problems formulated with the combined-field integral equation. Using the multilevel fast multipole algorithm (MLFMA) parallelized on a cluster of computers, we easily solve scattering problems that are discretized with tens of millions of unknowns. For the efficient parallelization of MLFMA, we propose a hierarchical partitioning scheme based on distributing the multilevel tree among the processors with an improved load-balancing. The accuracy of the solutions is demonstrated on scattering problems involving spheres of various radii from 80lambda to 110lambda. In addition to canonical problems, we also present the solution of real-life problems involving complicated targets with large dimensions.