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Anisotropic Diffusion
Posted Jul 9, 2013, 7:15 a.m. EDT Chemical Reaction Engineering 2 Replies
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Hi,
I have a 2D geometry in which I want to define anisotropic diffusion. When I select this option in the menu and solve the problem I get weird results. When I check again the options, 'anisotropic diffusion' has been automatically changed to 'Diagonal' and I think this is what is causing the problem.
Any suggestion is much appreciated
I have a 2D geometry in which I want to define anisotropic diffusion. When I select this option in the menu and solve the problem I get weird results. When I check again the options, 'anisotropic diffusion' has been automatically changed to 'Diagonal' and I think this is what is causing the problem.
Any suggestion is much appreciated
2 Replies Last Post Jul 9, 2013, 9:22 a.m. EDT
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Posted:
1 decade ago
Dear Borja,
I have seen this before, it does not cause problems. If you select anisotropic diffusion but provide constants that are only diagonal COMSOL automatically does that switch. Similarly if you put off-diagonal terms symmetrically then COMSOL switches to symmetric.
Nagi Elabbasi
Veryst Engineering
I have seen this before, it does not cause problems. If you select anisotropic diffusion but provide constants that are only diagonal COMSOL automatically does that switch. Similarly if you put off-diagonal terms symmetrically then COMSOL switches to symmetric.
Nagi Elabbasi
Veryst Engineering
Please login with a confirmed email address before reporting spam
Posted:
1 decade ago
Thanks for the answer.
You are right, that seems to work fine when I solve the diffusion equation in my particle with a constant concentration boundary condition. However, when I couple this, via flux term, with a convection diffusion equation to solve for the macroscopic concentration in a packed bed, the concentration profile does not make sense.
Borja
You are right, that seems to work fine when I solve the diffusion equation in my particle with a constant concentration boundary condition. However, when I couple this, via flux term, with a convection diffusion equation to solve for the macroscopic concentration in a packed bed, the concentration profile does not make sense.
Borja