Simple Method to Reduce Computation Time in Planar Air-Gap 3-D FEM Non-Linear Problems

In this article, an easily implementable method to reduce the CPU time for some 3-D finite-element method (FEM) problems is presented. A translational displacement between two parts on both sides of a planar air gap is considered with a change of coordinates in the air-gap region along the z-axis. To achieve this, formulation and postprocessing are slightly adapted. The proposed method is applied to an academic problem and to an axial electric rotating machine. Results are compared with a usual method. Time savings, ease of implementation, and precision on results are really encouraging with a strong reduction in the CPU time, keeping a low relative deviation. The method could be easily applied to any configurations with the planar air gap as an axial motor.