CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   OpenFOAM Post-Processing (https://www.cfd-online.com/Forums/openfoam-post-processing/)
-   -   WallShearStress for settlingFoam (https://www.cfd-online.com/Forums/openfoam-post-processing/106399-wallshearstress-settlingfoam.html)

Elise August 28, 2012 04:25

[solved] WallShearStress for settlingFoam
 
I did a case with settlingFoam in a special geometry; water is flowing into a hemisphere as well as sand.

Now i would like to calculate the bed shear stress at this hemisphere, but the function wallshearstress only uses nu from the singlephase transport model.

What do I have to change in the file wallshearstress.C or createFields.H to obtain this wall shear stress in postprocessing mode?

I can also do the calculation myself with

tau = mu * dU/dy

Only how do I calculate this gradU normal to this hemisphere does wallgradU does this automatically or do I have to add a normal vector but how to do this?

Elise August 28, 2012 05:50

I changed the wallGradU.C file to

wallGradU.boundaryField()[patchi]= - U.boundaryField()[patchi].snGrad*patch().nf();

Is this the correct way to do this or does the wallgradU allready gives the values related to the wall instead of to the
defined axes?

Answere was in http://www.cfd-online.com/Forums/ope...tml#post186008


All times are GMT -4. The time now is 11:46.