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Setting Values of the Solution Vector

Posted 18 nov 2011, 14:29 GMT-5 Low-Frequency Electromagnetics, Parameters, Variables, & Functions, Studies & Solvers Version 4.0a, Version 4.1, Version 4.2, Version 4.2a 2 Replies

Matt Cherry
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Hello,

Is there a way to, say, in the frequency dependent electromagnetic problem, set the the value of electric potential in a certain domain as some constant, basically fixing some of the degrees of freedom in the problem? I know I could just use Ampere's Law in that particular domain, but coupling between multiple domains with guage fixing gets kind of messy, and I'm looking for a more general way to set values in the solution vector anyway.

Thanks for any help,
-Matt
2 Replies Last Post 8 dic 2011, 12:07 GMT-5
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 19 nov 2011, 09:44 GMT-5
Hi

normally the ("right hand side") BCs values you define in a frequency solver sequence are the amplitudes of a sinus excitation and NOT constants (harmonic development).
You need probably to do two models, to solve for stationary with DC values and for the harmonic case. Then check if your model does not allow to simply add the two

--
Good luck
Ivar
Hi normally the ("right hand side") BCs values you define in a frequency solver sequence are the amplitudes of a sinus excitation and NOT constants (harmonic development). You need probably to do two models, to solve for stationary with DC values and for the harmonic case. Then check if your model does not allow to simply add the two -- Good luck Ivar
Matt Cherry
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Posted: 1 decade ago 8 dic 2011, 12:07 GMT-5
Thank you very much for your reply,

When I say constant, I really mean that i want the values of the scalor electric potential to equal zero in the air domains of the problem, not on the boundary. There would be a jump on the boundaries between conductive and non-conductive domains. I could just use Ampere's Law in the air domain, but then I have to couple the conductive and non-conductive domains somehow, which may be difficult when gauge fixing is active. Do you have any ideas on this?

Thanks again,
-Matt
Thank you very much for your reply, When I say constant, I really mean that i want the values of the scalor electric potential to equal zero in the air domains of the problem, not on the boundary. There would be a jump on the boundaries between conductive and non-conductive domains. I could just use Ampere's Law in the air domain, but then I have to couple the conductive and non-conductive domains somehow, which may be difficult when gauge fixing is active. Do you have any ideas on this? Thanks again, -Matt

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