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Which way round do the fluxes go?
Posted 2 sept. 2016, 11:24 UTC−4 Modeling Tools & Definitions Version 5.2 0 Replies
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I have a model using general form PDE with different domains governed by PDEs with a different flux. One domain is inside the other and it is in 3D (see attached picture). I need a condition across the interior boundary such that:
n . (\Gamma_i - \Gamma_o) = n . v
where \Gamma_i is the flux of the inside domain, \Gamma_o is the flux in the outside domain, n is the outward normal of the inner domain and v is a constant.
I have 2 questions:
*** Do I need to use an assembly? Or can I specify this on the one domain between the two regions (and therefore just need a union).
*** I think (from looking at the comsol guide) the flux/source condition on an interior boundary (given on comsol as $-n . \Gamma = g - qu$) translates to actual maths as $-n . (\Gamma_1 - \Gamma_2 = g - qu)$. Which $n$ is being used here and which way round are $\Gamma_1$ and $\Gamma_2$? I have been trying to work out whether it matters but I think it does to choose the sign of the constant.
Thanks to anyone that can help!
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Hello Ian Roper
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