An optimal formulation for 3D moving conductor eddy current problems with smooth rotors

A finite-element technique for modeling 3D transient eddy currents in smooth-rotor conductors moving at a constant velocity is described. The method does not require the electric scalar potential inside conducting regions in moving-conductor problems. The interface between moving and stationary conductors requires a jump in magnetic vector potential when the electric scalar is not present. This is handled using a thin-surface element. The method has been implemented in the MEGA software package for modeling 2D and 3D electromagnetic fields. Eddy-current regions are modeled using a magnetic vector potential. Nonconducting regions require magnetic scalar potentials. Validation by comparison with experiment has been carried out. The study of eddy currents in an electromagnetic launcher is considered