Summary

Prior to r10.1.3, EMSolution did not allow the use of sliding surfaces closed in the orthogonal direction of motion, requiring the ends to be on symmetry surfaces, periodic surfaces, external boundaries, or the central axis of cylindrical coordinates. We are pleased to report that this restriction has been removed.

Explanation

For example, consider the case where a movable part moves from the back to the front of the figure as shown in Fig. 1. In the 2D mesh that forms the base of the 3D model, the sliding surface is represented by a closed circumference. The input is the same as before. If the 2D mesh is extended in the z-direction using 2D_to_3D to create a 3D model, the sliding surface becomes cylindrical. In this case, the upper and lower surfaces of the model are set to anti-periodic symmetry. Since this model is axisymmetric and can be calculated with a two-dimensional model, there is no need to make this type of 360-degree model. However, we have made a 360-degree model in consideration of cases where there is no axisymmetry or periodic symmetry. Also, for circumferential sliding motion, it is now possible to define a sliding surface closed in the r-z plane, which was previously not possible.

Fig.1 Two-dimensional model mesh

Fig. 2 shows the results of the analysis. The figure shows half of the model so that the cross section can be seen. Since we performed a magnetostatic field analysis, the magnetic field distribution is not affected by the motion and does not change.

Fig.2 Result of magnetic field strength analysis

Currently, EMSolution cannot model periodicity in two directions. Also, when using sliding surfaces, periodicity is assumed in the direction of motion. Therefore, in the model above, even if there is periodicity in the circumferential direction, the model must be 360 degrees in the circumferential direction. We intend to improve this in the future.

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Analysis Model

・ input.ems : Input condition file
・ pre_geom2D.neu : Stator mesh file
・ rotor_mesh2D : Rotor mesh file
・ 2D_to_3D : 2D mesh stacking file