# nutUSpaldingWallFunction

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 February 26, 2013, 16:01 nutUSpaldingWallFunction #1 Member   Dogan Join Date: Nov 2012 Location: Bochum/Germany Posts: 42 Rep Power: 13 Hi everybody, I am working on the wall treatment in OpenFOAM, and as i've learned, the so called nutUSpaldingWallFunction is giving very good results in all y+ regions. I also made some calculations with it using kOmegaSST turbulence model, and as expected, it gave me very good results. But i would like to go deep with this wall treatment, and i would like to know the formulation (governing equations) of this wall function. Does anyone can help me with this? how can i find the governing equations of nutUSpaldingWallFunction in OpenFOAM? thanks in advance Dogan

 March 30, 2013, 05:10 #2 Senior Member     Fumiya Nozaki Join Date: Jun 2010 Location: Yokohama, Japan Posts: 266 Blog Entries: 1 Rep Power: 18 Hi dogan, You might want to read the doctoral thesis by Dr. Eugene de Villiers(pp.80-81): http://powerlab.fsb.hr/ped/kturbo/Op...ersPhD2006.pdf Best regards, Fumiya

March 31, 2013, 13:32
#3
Senior Member

Join Date: Nov 2012
Posts: 171
Rep Power: 13
Hi,

the source paper:

Spalding, a single formula for the law of the wall. Journal of applied mechanics. 1961.

The story is complete there.

Quote:
 Originally Posted by dogan Hi everybody, I am working on the wall treatment in OpenFOAM, and as i've learned, the so called nutUSpaldingWallFunction is giving very good results in all y+ regions. I also made some calculations with it using kOmegaSST turbulence model, and as expected, it gave me very good results. But i would like to go deep with this wall treatment, and i would like to know the formulation (governing equations) of this wall function. Does anyone can help me with this? how can i find the governing equations of nutUSpaldingWallFunction in OpenFOAM? thanks in advance Dogan

 April 2, 2013, 06:14 #4 Member   Dogan Join Date: Nov 2012 Location: Bochum/Germany Posts: 42 Rep Power: 13 Thanks a lot to you all, it really helped your answers. regards Dogan

February 5, 2018, 11:58
#5
Member

Amir
Join Date: Jan 2017
Posts: 32
Rep Power: 8
Hello Foamers,

I am solving the 3D flow around the cylindrical pile in OpenFOAM 2.3, as a single-phase with RANS (k-omegaSST) with simpleFoam.
I want to solve it with low-Re model near the bed.
my mesh is generated with ICEM and the yplus is less than 2 for all cells in bed. I have used the o-grid mesh around the cylinder.
the boundary that has been applied to the bed for turbulence properties are:
Code:
```    BED
nut
{
type            calculated;
value           uniform 0;
}
omega
{
type            omegaWallFunction;
value           uniform 1000;

}
k
{
type            fixedValue;
value           uniform 1e-10;
}```
and here is my fvSchemes

Code:
```ddtSchemes
{
}

{
default         Gauss linear;
}

divSchemes
{
default         none;
div(phi,k)      bounded Gauss upwind;
div(phi,omega)  bounded Gauss upwind;
}

laplacianSchemes
{
default         Gauss linear limited 0.333;
}

interpolationSchemes
{
default         linear;
}

{
default         limited corrected 0.333;
}

fluxRequired
{
default         no;
p;
Phi;
}```
I have attached the results of the bed shear stress from wallShearStress utility. as you can see there is a problem in area generated with o-grid. changing the size of the mesh or resolution of the mesh do not change anything.

when I used the nutUSpaldingWallFunction for nut the results are very good.
I think the problem is the orthogonality of the cells in o-grid part!!
Could anybody help me with this problem?

Bests,
Amir
Attached Images
 bedshearstress.png (91.4 KB, 178 views)

 August 2, 2023, 06:16 #6 New Member   Join Date: Aug 2023 Posts: 3 Rep Power: 2 OpenFOAM 2.3's simpleFoam is helping me solve the three-dimensional flow around the cylinder using Reynolds Averaged Navier-Stokes (RANS, k-omega SST). Near the bed is where I hope to find a solution, with a low-Re model. All bed cells in my ICEM-generated mesh have yplus values below 2, and the mesh itself is smooth. Around the cylinder, I've utilized an o-grid mesh. geometry dash Last edited by reichelmarcia; August 7, 2023 at 05:34.