# Description

LS-DYNA's EM solver provides a novel FEM/BEM monolithic approach which allows the user to solve non-linear time transient actuator or electric motor problems while removing the need to mesh the air and fully couple the results to LS DYNA's mechanical solver. This benchmark problem has been proposed by N. Allen and D.Rodger in "Description of TEAM Workshop Problem 24: Nonlinear Time-Transient Rotational Test Rig". School of Electrical Engineering, University of Bath, Bath, BA2 7AY, U.K. It consists of a rotor mounted on a nonmagnetic stainless steel shaft and a fixed stator. The rotor is locked at a specific angle with respect to the stator. The steel magnetization curve and conductivity have been measured and are provided as input. The coils are modelled as stranded conductors with a provided voltage, resistance and number of turns. Coil current, torque, search coil flux, and Hall probe flux density are Post Treatment quantities.

To solve this problem, either the current is considered a known quantity and directly imposed (see current_team24.k). In that case, the coil is not part of the FEM/BEM system (The current generates a external source term on the FEM/BEM system) and therefore mtype=1 in the coil's associated EM_MAT. The alternative is to use a voltage driven coil. In that case, the current is considered as an unknown and therefore mtype=2 in the coil's associated EM_MAT. In addition to the voltage, the resistance and the number of turns must also be provided in EM_CIRCUIT_SOURCE.