On the use of the impedance boundary condition with an indirect boundary formulation

The use of the impedance boundary condition (IBC) with an indirect boundary formulation is illustrated. The use of the IBC not only reduces significantly the computation effort but also enables the real nonlinear eB-H characteristic of the material to be presented. The indirect boundary formulation locates the source points and the observation points on two different boundaries. The particular case of a boundary-type solution based on the very simple and efficient method of fundamental solutions is considered. The formulation derived in the present work is valid for multiple conducting magnetic and/or nonmagnetic cylinders having arbitrary cross-sections. An illustrative example is given for the case of two circular conductors (one magnetic and the other nonmagnetic) carrying an impressed total current. Results are compared with those obtained without the use of the IBC approximation