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Boundary conditions in magnetic field no currents physics
Posted 18 nov. 2015, 07:36 UTC−5 Low-Frequency Electromagnetics, Modeling Tools & Definitions, Parameters, Variables, & Functions Version 5.1 2 Replies
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Hi
I am trying to calculate the field around a permanent magnet for which I am using the ACDC module with the magnetic field no currents (mfnc) physics. I also have several symmetry planes in my geometry which I would like to utilize to reduce the size of my mesh, but this gives some problems.
What I want to do, is described very nicely here:
www.comsol.com/blogs/exploiting-symmetry-simplify-magnetic-field-modeling/
Boundaries for which n dot B = 0 (surface vector dot field) can be specified with the magnetic insulation boundary condition. Here the field is parallel to the surface.
I can however not figure out how to specify boundaries where n x B = 0 (surface vector cross field), eg. where the field is normal to the surface.
Unfortunately the "perfect magnetic conductor" boundary condition used in the link above, is not available in the mfnc physics. Do you have any suggestions on how to impose the same boundary condition in mfnc, on how to eventually use boundary conditions from mf physics in the mfnc physics (if possible, I am new to this), or if there is some good mathematical reason why this boundary condition is not available in the mfnc physics?
Cheers,
Simon (version 5.1)
I am trying to calculate the field around a permanent magnet for which I am using the ACDC module with the magnetic field no currents (mfnc) physics. I also have several symmetry planes in my geometry which I would like to utilize to reduce the size of my mesh, but this gives some problems.
What I want to do, is described very nicely here:
www.comsol.com/blogs/exploiting-symmetry-simplify-magnetic-field-modeling/
Boundaries for which n dot B = 0 (surface vector dot field) can be specified with the magnetic insulation boundary condition. Here the field is parallel to the surface.
I can however not figure out how to specify boundaries where n x B = 0 (surface vector cross field), eg. where the field is normal to the surface.
Unfortunately the "perfect magnetic conductor" boundary condition used in the link above, is not available in the mfnc physics. Do you have any suggestions on how to impose the same boundary condition in mfnc, on how to eventually use boundary conditions from mf physics in the mfnc physics (if possible, I am new to this), or if there is some good mathematical reason why this boundary condition is not available in the mfnc physics?
Cheers,
Simon (version 5.1)
2 Replies Last Post 18 nov. 2015, 10:33 UTC−5
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Posted:
9 years ago
Dear Simon,
please have a look at this mfnc model that exploits 8-fold symmetry of a horseshoe magnet.
ch.comsol.com/model/permanent-magnet-78
Best regards,
Sven Friedel
please have a look at this mfnc model that exploits 8-fold symmetry of a horseshoe magnet.
ch.comsol.com/model/permanent-magnet-78
Best regards,
Sven Friedel
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Posted:
9 years ago
Dear Sven
Thank you for the answer, that was exactly what I was looking for.
Best regards,
Simon
Thank you for the answer, that was exactly what I was looking for.
Best regards,
Simon