Discussion Forum

Hello all,

I am a relatively new COMSOL user attempting to model an electric motor design (of the out runner type) with the Rotating Magnetic Machinery physics. Currently I am working on the permanent magentas in the rotor, and have been unable to get them to work properly. I have modeled the permanent magnet using the Magnetic Conservation node with the constitutive relation . The magnet is attached to a steel ring which is the body of the rotor. Currently I am only modeling one magnet but will eventually have 14 magnets arrayed periodically within the ring. I have two problems:

1) When I perform the study I get the message that the relative error is greater than the tolerance. I have been able to play with things so the relative error is below ~50 each time I run the study, however this is still much greater than the tolerance (.001).
2) Despite the previous issue, the study does go to "completion," and I get some results that I can look at. However the results show a minuscule field within my magnet, much lower than the 1.3 T I have assigned to the magnet. Essentially the magnet does not display any field.

I am assuming the two issues are related, though I am not positive. Does this problem have to do with my meshing? Or am I implementing the Magnetic Conservation node improperly?

Any assistance will be greatly appreciated!

-Eli Zoghlin