2023-12-15T16:04:10.000-0500

MAGNET

Conductor dividing mesh with odd periodic causes issues. Please upgrade to the latest release of Simcenter MAGNET to avoid this issue altogether.

An odd-periodic 3D model can produce erroneous results if a conductor divides the non-conductor mesh into multiple disjoint regions. This especially concerns "slab" models (2D models solved in 3D). We have examples of this happening with each of the 3D solvers. The figure below shows a thin slab model of a motor whose conducting rotor divides the non-conductor mesh into disjoint inner and outer regions. This is followed by the initial current solution, where an anomalous hot spot appears on the rotor.

MAGNET should either support this situation, or else check for it and issue an error code explaining the limitation.

**Note**: This discussion is also relevant to the type of model shown below. One may think that the conducting region does not divide the non-conductor mesh into two regions, but in fact the master and slave odd-periodic faces meet at the axis, and because the solution there must be equal and opposite on master and slave, it constrains the solution to zero, which is the same as Field Normal, which makes that edge "non-conductor".

**Possible workarounds:**

- Double the size of the model to give it even-periodic symmetry;
- Put a hole through the conductor to connect the disjoint regions;
- Assign a low conductivity to enough of the non-conductor mesh that it becomes no longer divided. Note that this could slow down convergence.