Hello, I want to use a SGS
 

Hello,

I want to use a SGS model + wall function.

I have read in a threat that to do so you have to
declare "nuSgsWallFunction" as type BC for nuSgs.

However, while doing this, I have the following error message when runninf the application:

I use openFoam 1.3 version.

How should it be declared so taht it wokds ?

--------------------------------------------
--> FOAM FATAL IO ERROR : keyword value is undefined in dictionary "/home/anne/OpenFOAM/anne-1.3/run/OBSTACLE_HIGH_RE/0/nuSgs::bottomWall"

file: /home/anne/OpenFOAM/anne-1.3/run/OBSTACLE_HIGH_RE/0/nuSgs::bottomWall from line 245801 to line 245801.

From function dictionary::lookupEntry(const word& keyword) const
in file db/dictionary/dictionary.C at line 152.

FOAM exiting
------------------------------


Thanks you

anne

You need to add a value entry
 

You need to add a value entry to your nuSgsWallFunction boundary condition, like so:

bottomWall
{
type nuSgsWallFunction;
value uniform 1e-10;
}

Most boundary conditions require such a placeholder value entry even though the initial specification is not important. It is simply a result of the way the boundary class is derived from its base type.

thanks , it runs now Ann
 

thanks ,

it runs now

Anne

Hi again, I would like just
 

Hi again,

I would like just some clarification:

when using LES+wall function,

Is the correct way to apply a fixed zero type BC for
U ?

Anne

Yes, wall functions are applie
 

Yes, wall functions are applied to the velocity field via an enhanced viscosity.

tau_w = (nu + nu_w) * du/dn_w

where the appropriate nu_w is calculated using the wall function.

Dear All, I also try to do
 

Dear All,

I also try to do LES with wall functions.

My problem is, that if I apply the type "nuSgsWallFunction" to a wall patch, as mentioned above, I get the error message: This is an unknown patch field, if I try to decompose the case.

If I run it without decomposition the solver starts and doesn't complain about the patch.

In the .OpenFOAM/controldict the switch disallowDefaultFvPattchField is set to 1.

I'm using the 1.4.1-dev version of Foam.

So I'm not shure if wall functions are applied or not. Can someone help?

Thanks in advance
Thomas