In your test case, have you made the top surface a wall or a constant pressure outlet patch? Sounds like that is what you want. That will help keep the 'outlet' behaving physically.

Hi Nima
I've changed the type of outlet pressure to buoyantPressure but the following error obtained:
--> FOAM FATAL ERROR:
Continuity error cannot be removed by adjusting the outflow.
Please check the velocity boundary conditions and/or run potentialFoam to initialise the outflow.
Total flux : 1e-300
Specified mass inflow : 1.27e-05
Specified mass outflow : 0
Adjustable mass outflow : 0


From function adjustPhi(surfaceScalarField& phi, const volVectorField& U,const volScalarField& p
in file cfdTools/general/adjustPhi/adjustPhi.C at line 115.

FOAM exiting

I try to implement groovybc and tell you the result.

Outlet Pressure
 

Hi Kwardle,
What do u mean exactly by constant pressure outlet patch. could u please check my file for this case? I don't know how to consider constant pressure above the surafce and hydrostatic pressure below the surface.

Mohammad,
I took at your 0 BCs. You have a boundary in p_rgh called atmosphere which is not used. Anyway, your outlet patch is not set up correctly. You will want to use inletOutlet for alpha1, totalPressure for p_rgh and pressureInletOutletVelocity for U on your outlet patch. If you had not set up the inlet as you have done with a partial patch of alpha1, I think in order to get this to solve and not blow up you would have also had to make the upperWall an 'outlet' boundary with all the same BC types as your named outlet patch. Attached is a 0 directory with the changes that work for me.

Here is an animation through 1s.

https://sites.google.com/site/kwardl...edirects=0&d=1

Please take a close look through the BCs and make sure it is clear what I have changed so you can do it yourself in the future. Hope this helps!
-Kent

new case
 

Hi Kwardle,
Thanks a lot for your attention. I did what you said and the results obtained was the same as yours. In order to model my case, I built a model and implement the required changes. It's result is a little strange. I reallly couldn't explain what happen.
Here is my file:
http://www.4shared.com/file/4k8mRux_/D13T.html

Thanksgod, You really made me hopefull for learning openFoam better.

Please post the file here directly. I cannot get the file from your link.

flow on step new case
 

really thanks Kwardle, Mesh file is bigger than the uploading limit. what shoul I do? could u please give me your email.

Hi,
Is it generated from blockMesh? If so, just upload the blockMeshDict only without the mesh.
-Kent

Hi Mohammad !

Can u upload file or post your solver on forum ? This is best reference.
thanks

phuc