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Wrong pole directions give "accurate" results in permanent magnet model

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I'm modelling a simple permanent magnet with north and south pole.

The problem I'm having is using the remanent flux density, the magnetic field I've initialized has both north and south pole in the same direction, yet the solution given of the magnetic flux density is fairly concordant with what I'm getting in a hall probe.

Intuitively, this would be clearly wrong as the streamline/arrow surface are assymetrical and don't resemble the field lines that you'd typically see in a permanent magnet. However, with opposite directions, the solution does not resemble the values of the hall probe at all.

I'm hoping that someone who is more experienced in magnets would shed some light on this, and let me know if the results of my model are purely coincidental or if there is something else to it.

Thanks



1 Reply Last Post 2021年3月3日 GMT-5 10:29
Robert Koslover Certified Consultant

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Posted: 4 years ago 2021年3月3日 GMT-5 10:29
Updated: 4 years ago 2021年3月3日 GMT-5 10:31

First, the remanent flux density in an ideal bar magnet should be all in one direction. You should be specifying the direction of the flux density, not poles per se. Second, the blocks you have labeled "north" and "south" and which you have stacked along the z-direction, are (unexpectedly) magnetized in the x-direction! See image attached. I suspect you intended to magnetize the structure in the z direction, right? If so, that's your problem.

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Scientific Applications & Research Associates (SARA) Inc.
www.comsol.com/partners-consultants/certified-consultants/sara
First, the remanent flux density in an ideal bar magnet should be all in one direction. You should be specifying the direction of the flux density, not poles per se. Second, the blocks you have *labeled* "north" and "south" and which you have stacked along the z-direction, are (unexpectedly) magnetized in the x-direction! See image attached. I suspect you intended to magnetize the structure in the z direction, right? If so, that's your problem.

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