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Extrapolating BH curve & Relative permeability


The BH curve from experimental data is normally in the first quadrant.

When I extrapolate using the given methods, the extrapolated BH curve in the 3rd quadrant is unrealistic and am concerned about the -ve values for both H and B.

Am thinking of manually mirroring the data along y = x, i.e. by multiplying with a -1 for the both quantities and then load the data in Comsol, because am not sure what Comsol does with negative B-H quantities.

To set relative permeability, I copied the expression for normB and normH under the property group of BH curve, i.e.

1/mu0_const * BH(normH[m/A])[T] / sqrt(H1^2+H2^2+H3^2)

In addition I disabled the HB curve, to ensure that its only the BH curve that is active during simulations.

I just want to confirm whether I have done the right thing.


1 Reply Last Post Sep 19, 2013, 9:27 AM EDT
COMSOL Moderator

Hello John Wanjiku

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Christopher Burgy
Posted: 4 years ago Sep 19, 2013, 9:27 AM EDT
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