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Magnetization independent variables

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Hi,
I am trying to model a material with the AC/DC module using 3.5a and I have equations which describe the magnetization of the material in the horizontal (x) and vertical (y) directions. BOTH equations use the horizontal magnetic field to determine the magnetization (Bx_emqa).

I am using the constitutive relation B=mu0(H+M) and defining M as the equations I described above. This creates problems when I try and solve the model as I think COMSOL will not allow me to define magnetization in the vertical (y) direction with a horizontal field (x direction). Can anyone verify this for me? Does anyone have any ideas on how I can represent the horizontal field without using Bx_emqa/mu0? I have already tried defining Bx as sqrt(normB^2 +By^2) , but that doesn't work either. Functions maybe? or some other way?

Thanks for your help.

2 Replies Last Post Jul 26, 2010, 9:51 a.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Jul 24, 2010, 8:17 a.m. EDT
Hi
did you define the derivative of the material function ? I believe this is mandatory, check the doc

--
Good luck
Ivar
Hi did you define the derivative of the material function ? I believe this is mandatory, check the doc -- Good luck Ivar

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Posted: 1 decade ago Jul 26, 2010, 9:51 a.m. EDT
Thanks for your help. After receiving your comment I manually defined the material derivative for each variable, but the system still does not converge. If I remove Bx_emqa from the My definition box, the system does converge. Do you have any other suggestions? Thanks again.
Thanks for your help. After receiving your comment I manually defined the material derivative for each variable, but the system still does not converge. If I remove Bx_emqa from the My definition box, the system does converge. Do you have any other suggestions? Thanks again.

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