Iterative solutions to hybrid electromagnetic problems

This paper discusses some iterative solving strategies for open-boundary electromagnetic problems, in which the global algebraic system is partly sparse and partly dense. Three problems are considered: electrostatic, time-harmonic skin effect, and time-harmonic scattering in open-boundary domains. These problems are formulated, respectively, by means of the hybrid FEM -BEM, FEM -DBCI and FEM -RBCI methods. The paper shows that in all these cases a very good solving strategy is based on the use of the GMRES solver, virtually applied to a suitably reduced algebraic system, in which the unknowns are only the truncation boundary ones.