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-   -   Help on a case of a Submarine which diverges (http://www.cfd-online.com/Forums/openfoam-solving/97282-help-case-submarine-diverges.html)

thibautsimon1 February 13, 2012 23:11

Help on a case of a Submarine which diverges
 
Hi all,

I'm working on a simple case of a submarine in Deep-water with a k-omega SST turbulence model, using simpleFoam resolution.
My problem is that the case always diverges after 1000 iterations, whatever I do on the mesh or in the settings.

Here my settings:


Number of cells: 4 100 000
Re= 1.146 E+006
y+=3.8
aspect ratio <100
Speed=0.717 m/s
Lenght of the hull=1.52m


And here is a part of my fvShemes file:

gradSchemes
{
default Gauss linear;
grad(p) Gauss linear;
grad(U) Gauss linear;
// grad(U) cellLimited Gauss linear 1;
}

divSchemes
{
default none;
div(phi,U) Gauss linearUpwindV grad(U);
div(phi,k) Gauss linearUpwind grad(k);
div(phi,omega) Gauss linearUpwind grad(omega);
div((nuEff*dev(T(grad(U))))) Gauss linear;
}


Someone has any idea of wath I did wrong?
Thanks for your help

linnemann February 14, 2012 03:19

2 Attachment(s)
Hi

Try these settings (OF 2.1).

Also you should always start with upwind on everything if you have stability issues. It's just BPG (Best Practice Guidelines). Also for Marine CFD look at this for BPG

thibautsimon1 February 15, 2012 21:07

Thanks a lot for your help,
I change few settings in my fvSchemes file, it seems to work now with this settings:

divSchemes:

div(phi,U) Gauss upwind grad(U);
div(phi,k) Gauss upwind grad(k);
div(phi,omega) Gauss upwind grad(omega);
div(phi,epsilon) Gauss upwind grad(epsilon);
div((nuEff*dev(T(grad(U))))) Gauss linear;
}

laplacianSchemes
{
default Gauss linear corrected;



I didn't change everythings cause I'm using the OF2.0

I let you know of my advances...

Thanks again


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