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-   -   How to solve coupled transport equations (http://www.cfd-online.com/Forums/openfoam-solving/58306-how-solve-coupled-transport-equations.html)

nandiganavishal November 20, 2008 19:21

Hi All I would like to solv
 
Hi All

I would like to solve coupled transport equations (not using relaxation technique). Can someone help me which tutorial I should go about looking to solve my problem.

These are my equations

ddt(C1) = - K1 * laplcian(C1) - K2 * laplacian (phi)
ddt(C2) = - K1 * laplcian(C2) - K2 * laplacian (phi)
K3 * laplacian (phi) = K4

where k1,k2,k3,k4 are some constant values..

Kindly help me out. I tried searching in the forum and could not get any information pertaining to this. I don't think I can use conjugate heat transfer solver for this.


Vishal

prashant24983 November 21, 2008 01:22

Look at scalarTransportFoam in
 
Look at scalarTransportFoam in the '$FOAM_SOLVERS/basic' folder

caw November 21, 2008 02:41

What about solving your equati
 
What about solving your equations in a segregated manner?

First solve:
K3 * laplacian (phi) = K4
and then:
ddt(C1) = - K1 * laplcian(C1) - K2 * laplacian (phi)
ddt(C2) = - K1 * laplcian(C2) - K2 * laplacian (phi)

or is there any coupling in C1 and C2?

Best regards
Christian

nandiganavishal November 21, 2008 16:53

Hi Christian and Prashanth,
 
Hi Christian and Prashanth,


Thanks a lot for the reply. I just missed one term in my equation. The equations look like this,

ddt(C1) = K1 * laplcian(C1) + K2 * laplacian (phi)
ddt(C2) = K1 * laplcian(C2) + K2 * laplacian (phi)
K3 * laplacian (phi) = K4 * f(C1) + K5 * f(C2) (Further this is a stiff equation)

where k1,k2,k3,k4 and k5 are some constant values.. I want to solve them directly and not using relaxation procedure.

Kindly offer some suggestions as to how to go about solving them. May I know which tutorial i have to follow.

Thanking You

Vishal

nandiganavishal November 22, 2008 17:43

Thanks a lot for the reply. I
 
Thanks a lot for the reply. I just missed one term in my equation. The
equations look like this,

ddt(C1) = K1 * laplcian(C1) + K2 * laplacian (phi)
ddt(C2) = K1 * laplcian(C2) + K2 * laplacian (phi)
K3 * laplacian (phi) = K4 * f(C1) + K5 * f(C2) (Further this is a
stiff equation)

where k1,k2,k3,k4 and k5 are some constant values.. f(C1) and f(C2) means the equation is a function of C1 and C2.

I want to solve
them directly and not using relaxation procedure.

Kindly offer some suggestions as to how to go about solving them. May
I know which tutorial i have to follow.

Thanking You

Vishal


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