Periodic Meshing

Periodic meshes are generated for the rotating machinery that has periodic structure in the rotational direction.

Meshing is applied to a part of the domain. The meshes are mirrored in the rotational direction.

This function is effective especially for the transient analysis and rotating machinery in the magnetic analysis.

Periodic meshing gives higher accuracy than usual meshing. It is considered to be effective especially for improving the symmetry of cogging torque.

Fig. 1 shows symmetric meshes generated on both sides of the plane of symmetry.

Plane of symmetry

Fig. 1: Periodic meshes of IPM motor

Fig. 2 is the result of cogging torque calculation. If a half-cycle waveform is mirrored laterally at 7.5 deg. and then mirrored vertically,

it is superimposed on the following half-cycle waveform. But they are slightly misaligned due to error.

Fig. 2: Cogging torque

Fig. 3 shows the error. The error of the periodic meshes is smaller in its degree than that of usual meshes.

Fig. 3: Error in symmetry