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Convection-diffusion equation with open boundary

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Hi,
I am trying to solve a convection- diffusion equation with an open boundary condition. I think this option is not available for this kind of problem. Does anybody had already tryed to solve a problem like that?
thanks,
Joana.

4 Replies Last Post 18.12.2013, 20:25 GMT-5

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Posted: 1 decade ago 08.10.2013, 21:28 GMT-4
Hi
I have been working on diffusion. Not sure about what your exact problem statement is, but their is a "open boundary" condition when you right click your model in comsol. I am talking about comsol 4.2. In 3.5 I think you can just specify 0 concentration on those boundaries.

Hi I have been working on diffusion. Not sure about what your exact problem statement is, but their is a "open boundary" condition when you right click your model in comsol. I am talking about comsol 4.2. In 3.5 I think you can just specify 0 concentration on those boundaries.

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Posted: 1 decade ago 09.10.2013, 09:51 GMT-4
Thanks for your answer.
I agree with you, there is an option for open boundary when you right click your model when you work with a transport of diluted species. I am working with atmospheric dispersion pollutant, and I chose model my problem with a convection diffusion equation, in the mathematics options. When I right click my model, the open boundary option does not appear. It causes a mistaken result, because comsol automaticaly includes a zero flux at this boundary. I am working with comsol 4.3.

Joana.
Thanks for your answer. I agree with you, there is an option for open boundary when you right click your model when you work with a transport of diluted species. I am working with atmospheric dispersion pollutant, and I chose model my problem with a convection diffusion equation, in the mathematics options. When I right click my model, the open boundary option does not appear. It causes a mistaken result, because comsol automaticaly includes a zero flux at this boundary. I am working with comsol 4.3. Joana.

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Posted: 1 decade ago 18.12.2013, 14:49 GMT-5
Hi Joana,
I have the same issue with implementing an open boundary condition with mathematics module. Did you solved the problem ?
Thanks a lot.

Clément
Hi Joana, I have the same issue with implementing an open boundary condition with mathematics module. Did you solved the problem ? Thanks a lot. Clément

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Posted: 1 decade ago 18.12.2013, 20:25 GMT-5
I didn't find any option for open boundary in the mathematics module. That's why I changed for the chemical transport module, which in my case works the same way.
Good luck,
Joana.
I didn't find any option for open boundary in the mathematics module. That's why I changed for the chemical transport module, which in my case works the same way. Good luck, Joana.

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