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Soft magnet close to permanent magnet

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Hello everyone,

I'm trying to simulate a pair of soft magnetic tips, actuated by an external permanent magnet.

In the folliwing pictures, you can see the two soft magnetic tips. The permanent magnet is placed on the left far from the soft magnets and it has a magnetization in the x direction. The soft magnetic behaviour is given by a BH curve.

I want to maximise the field gradient on the line in between the tips, but I have numerical issues when I change the shape of the design.

You can see for example on the first picture that the result is smooth and the field is high close to the tip. When I change the angle of the tips, the field gradient between increases or decreases. But sometimes the simulation gave non-smooth results as shown on the second picture. The gradient is dramatically decreased and the simulation sometimes doesn't converge. When I increase the total size of the soft magnets, this strange behaviour is more and more frequent.

I think these results are not physical but that it is a numerical problem, because it happens abruptly when increasing the magnets size. Have someone of you ever encountered this kind of results ? Do you have an idea of what it can come from ?

If you have an idea, i'll be very happy to hear from you.

Thanks,

Simon



0 Replies Last Post Jan 9, 2019, 10:50 a.m. EST
COMSOL Moderator

Hello Simon Dumas

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