An Iterative Solution to FEM-BEM Algebraic Systems for Open-Boundary Electrostatic Problems

This paper shows that the global system of equations in the hybrid FEM-BEM solution of open-boundary electrostatic problems can be efficiently solved in an iterative way by making use of the conjugate gradient solver for the FEM equations and the direct LU solver for the BEM equations. To do so, it is convenient to implement the BEM equations in a non-conventional way, by making the nodes for the potential non coinciding with the nodes for its normal derivatives