A Novel Split-Domain Iteration Scheme for Solution of Electromagnetic Diffusion Problems Modeled by the Hybrid Finite-Element-Boundary-Element Formulation

The hybrid finite-element (FE)-boundary-element (BE) formulation for electromagnetic diffusion problems provides some advantages in modeling including the following: 1) no truncation error; 2) ease of model generation; and 3) ease in solving problems involving moving conductors. However, the resulting matrix from this formulation loses its symmetry and is not banded, unlike the FE method. This results in significantly lower convergence rates in iterative solution schemes. A novel split-domain iteration scheme was developed to reduce computation times. The new scheme splits the domain into FE and BE subdomains. Only the matrix associated with the FE subdomain is solved subject to initial guessed potentials along the interface of two subdomains. The BE equation is then used as the corrector to update the prescribed interface potentials. The iteration scheme proceeds with these newly corrected interface potentials until the solution converges within the required prescribed error tolerances. In this paper, detailed descriptions of the newly developed scheme and performance comparisons are presented with a sample railgun problem.