[dogan]

Hello everyone,

i am currently working on a diffusor case and i am trying to find the best wall function to simulate a centrifugal pump in OpenFOAM. I have tried nutkWallFunction, nutUWallFunction and nutUSpaldingWallFunction. i got pretty good results in especially nutUSpaldingWallFunction.

My turbulence model is kOmegaSST, and i am using openFOAM 2.1.x version.

I have compared the results with CFX kOmegaSST, which uses automatic wall function treatment, and i realised that the OpenFOAM results are as good as CFX results even though nutUSpaldingWallFunction is a continuous wall function treatment.

In this point, i have couple of questions:

1) is there a difference between nutSpalartAllmarasWallFunction (which is used in the earlier versions of OpenFOAM) and nutUSpaldingWallFunction?

2) Is it possible automatic wall treatment in openFoam, and if yes, how?

3) i think the formulation of nutUSpaldingWallFunction is coming from the "Spalding's law of the wall" model, or is there a difference between the formulations of the code and the "law of the wall" theory?

thanks in advance to all of you