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Use Integral on Boundaries without Knowledge of the Boundary Conditions
Posted Aug 28, 2009, 2:25 a.m. EDT 3 Replies
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Hello,
I want to compute the (freqency dependant) current distribution in a body consisting of different materials. So I don't know the conditions on the boundaries, but the magnetic field's integral over the boundary equals the current.
If I use the boundary coupling variables and add a constraint in weak mode, the result is still dependant on the boundary conditions and depends on them. Is there any way to avoid this effect?
Thanks
Kurt
I want to compute the (freqency dependant) current distribution in a body consisting of different materials. So I don't know the conditions on the boundaries, but the magnetic field's integral over the boundary equals the current.
If I use the boundary coupling variables and add a constraint in weak mode, the result is still dependant on the boundary conditions and depends on them. Is there any way to avoid this effect?
Thanks
Kurt
3 Replies Last Post Oct 3, 2009, 1:11 p.m. EDT
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Posted:
1 decade ago
The fact that the body of interest to you is "consisting of different materials" suggests to me that it is not a simple boundary condition, like a perfect electric or magnetic conductor. Rather, your body of interest is part of the physics problem too, not just its boundary! Therefore, you should be meshing and including that body in your finite element model. This makes the boundary you have been talking about an interior boundary. As an interior boundary, you do not have to set a boundary condition on it at all. Rather, you set the volume conditions. But if you turn on the feature to specify interior boundary conditons, then be sure to specify "continuity" for the interior boundary in question. Then the fields everywhere, including on your interior boundary, should be computed correctly.
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Posted:
1 decade ago
I already tried to put a disc of air around it, but nonetheless I have to put some boundary conditions on it, which I don't know.
The current distribution inside the body determines the magnetic field outside and all I know about the field is that its integral over the boundary must equal the overall current in the body. However I don't match to model it correctly. Any further ideas are appreciated.
The current distribution inside the body determines the magnetic field outside and all I know about the field is that its integral over the boundary must equal the overall current in the body. However I don't match to model it correctly. Any further ideas are appreciated.
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Posted:
1 decade ago
I'm a bit confused about the nature of your problem. If the body has a current on (or in) it, then something is driving that current! Either it is being driven by external fields (which you would specify via external boundary conditions) or there is a current source on or connected to the body (such as an antenna driven by a microwave source). Are you using a current source on or in the body? Are you imposing an external field, incident wave, etc? Once you define the source of the current excitation, you will be a lot closer to an unambiguous definition of your problem.