A coupled BE-IBC formulation for multiple conductor eddy current problems

A coupled boundary-element-impedance-boundary-condition (BE-IBC) method in which the IBC can be applied to one or more, but not all, of the conducting regions is considered. It is shown that in order to apply the IBC selectively, it is necessary to consider carefully the manner in which the system matrix is formulated. The case of the electromagnetic mold, consisting of a right cylindrical conductor coaxial with an induction coil and short-circuit turn, is used as an application. The IBC is applied to the right cylinder, and the full BE formulation is used for the short-circuit turn. Results are presented for the electromagnetic pressure predicted by a full BE formulation and the coupled BE-IBC formulation and compared with published results. The accuracy of the numerical results and the advantages offered by the coupled BE-IBC formulation (reduced CPU time and memory requirements) are illustrated.<>