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Re: [femm] relative speed



brvusit@xxxxxxxx wrote:
Dear femm users,

I would like to know if is there the possibility to set, using femm,
the relative speed between two elements (i.e a magnet and a copper
bar). I would like to evidence eddy currents (i.e an electromagnetic
brake) in a copper disk due relative speed with a magnet.
Thank you.

Bruno Vusini
 

You can't really solve this problem directly with femm--the program doesn't model motion-induced eddy currents.

In certain cases, where the moving part is passing through a field that is spatially periodic, you can pose the problem in a way that approximately gives you what you are after.  An example would be the analyses of 3-phase induction motors that have been discussed recently.  In such cases, the effects of motion are approximated by doing the analysis in a reference frame that is fixed with respect to the moving parts.  The motion is then represented by choosing AC currents phased so that the field moves past the object (instead of the object moving past the field).  Without knowing more about your geometry, it's hard to say whether your problem is amenable to this sort of approximation.

Dave.
 

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