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probleme of simpleFoam convergence

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Old   January 23, 2014, 13:30
Default probleme of simpleFoam convergence
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xingyu SIMA
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hallo, foamers,
- Introduce of my case:
I'm doing a simulation of incompressible, turbulent flow, two outlets with different pressure, I use inletoutlet boundary condition.For solver i use simpleFoam.
There is no problem of my mesh quality, checked by 'checkMesh'.
If i close one outlet, it will converge well.
(Here in the attachments is my 'boundary conditions' 'fvScheme' and 'fvSolution'. and my result of calculate)
Problem:
You can see that the 'Initial residual' increase after about '50' iterations. I have no idea about this..
I think it's the problem of settings in 'fvScheme', but i don't know how to deal with it, because i don't understand these schemes at all. If anyone can give me some suggestions...
Thanks very much for your help.
resultat.txt
Attached Files
File Type: txt U.txt (1.3 KB, 9 views)
File Type: txt p.txt (1.2 KB, 7 views)
File Type: txt fvSchemes.txt (1.8 KB, 9 views)
File Type: txt fvSolution.txt (2.3 KB, 9 views)
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Old   January 24, 2014, 04:07
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xingyu SIMA
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is there anyone know why?
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Old   January 24, 2014, 04:45
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Alexey Matveichev
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Hi,

As you've only provided fvSchemes and fvSolution, try using PCG instead of GAMG and PBiCG instead of smoothSolver.

Attach solution logs at least if you've got rather secret case files.
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Old   January 24, 2014, 05:38
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Quote:
Originally Posted by alexeym View Post
Hi,

As you've only provided fvSchemes and fvSolution, try using PCG instead of GAMG and PBiCG instead of smoothSolver.

Attach solution logs at least if you've got rather secret case files.
Thanks very much for your reply, log file is this: resultat.txt . i just copy some iterations, can you open it?
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Old   January 24, 2014, 08:30
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Alexey Matveichev
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Well, you've just shown a log with GAMG and smoothSolver. Still there are lots of possibilities of what's happening. So I can keep guessing or let it go.

1. What are your BCs for turbulence model?
2. What will happen if you remove relaxation?
3. Are you sure there is steady state in the problem?
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