Menu

Discussion Forum

New Discussion
Filtrer

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

concentration jumps in transport of diluted species model

Posted 12 janv. 2016, 03:20 UTC−5 6 Replies

Hansong Xue
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Hello,

I have transport of diluted species model defined on two domain with one interior boundary condition, and I want to define a concentration jumps at the interior boundary. Let's says the ratio of the concentration at the interior boundary is some value 0.5. By the way, there is flux discontinuity already defined there.

Anyone knows how to do it?

thanks,
Hansong
6 Replies Last Post 14 janv. 2016, 20:48 UTC−5
Lasse Murtomäki
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 9 years ago 12 janv. 2016, 04:30 UTC−5
I have done what you asked by using two physics nodes, one for each domain. Let's say that in domain 1 you have concentration C1 and in domain concentration C2 (they are the same molecules but in different domains). At the internal boundary, in domain 1 define

C1 = P*C2

and in domain 2

C2 = C1/P

and P is the partition coefficient between the domains.

For closer details, you can have a look at

dx.doi.org/10.1016/j.mbs.2014.03.014

BR
Lasse
I have done what you asked by using two physics nodes, one for each domain. Let's say that in domain 1 you have concentration C1 and in domain concentration C2 (they are the same molecules but in different domains). At the internal boundary, in domain 1 define C1 = P*C2 and in domain 2 C2 = C1/P and P is the partition coefficient between the domains. For closer details, you can have a look at http://dx.doi.org/10.1016/j.mbs.2014.03.014 BR Lasse
Hansong Xue
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 9 years ago 12 janv. 2016, 08:17 UTC−5
Hi Lasse,

thanks for the reply. How about define flux discontinuity when have two physics nodes? Shall I use the same way you mentioned below for defining flux discontinuity or I can use identity pairs for it?

regards,
Hansong
Hi Lasse, thanks for the reply. How about define flux discontinuity when have two physics nodes? Shall I use the same way you mentioned below for defining flux discontinuity or I can use identity pairs for it? regards, Hansong
Lasse Murtomäki
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 9 years ago 12 janv. 2016, 08:23 UTC−5
I do not understand these identity pairs, never used them.

Flux discontinuity is formed if you define different fluxes in domain 1 and 2 at the boundary. But as you certainly understand, flux discontinuity means accumulation or depletion of material at the interface.

BR
Lasse
I do not understand these identity pairs, never used them. Flux discontinuity is formed if you define different fluxes in domain 1 and 2 at the boundary. But as you certainly understand, flux discontinuity means accumulation or depletion of material at the interface. BR Lasse
Hansong Xue
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 9 years ago 13 janv. 2016, 03:57 UTC−5
As what you said above, I use two physics nodes, one for each domain. And I set the concentration and flux are continuous across the internal boundary, but now it is not converged. Do you know any idea why? The difference is just that when I use 1 physics node defined on two domain, by default the concentration and the flux are continuous and it is converged.

thanks,
Hansong
As what you said above, I use two physics nodes, one for each domain. And I set the concentration and flux are continuous across the internal boundary, but now it is not converged. Do you know any idea why? The difference is just that when I use 1 physics node defined on two domain, by default the concentration and the flux are continuous and it is converged. thanks, Hansong
Lasse Murtomäki
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 9 years ago 13 janv. 2016, 04:07 UTC−5
I need to see the model file, can you submit to me privately?

Lasse
I need to see the model file, can you submit to me privately? Lasse
Hansong Xue
Send Private Message Flag post as spam

Please login with a confirmed email address before reporting spam

Posted: 9 years ago 14 janv. 2016, 20:48 UTC−5
Hi Lasse,

I have figured out my problem already. It is just the sign of flux at the internal boundary which cause not convergence.

thanks,
Hansong
Hi Lasse, I have figured out my problem already. It is just the sign of flux at the internal boundary which cause not convergence. thanks, Hansong

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.

Suggested Content