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-   -   Wall function coefficients (http://www.cfd-online.com/Forums/openfoam-solving/58143-wall-function-coefficients.html)

seb62 January 8, 2009 10:53

Hi everyone, I am currently
 
Hi everyone,

I am currently working with RANS turbulence models on a flat plate.
As a postprocessing, I am plotting U+ = f(y+) at different x locations. The slope in the log region is good, but I have a shift between the more or less commonly accepted log law (U+ = (1/kappa)(y+) + B ; B close to 5) and my results.
Then looking at the turbulence properties file, I can see two constants for the wall function : kappa and E.
Does someone know the meaning of E and if it is linked to what I call B in the log law?

Thanks a lot

Seb

antonio_ing January 8, 2009 11:07

actually the log law can be ex
 
actually the log law can be expressed in two different ways:

1)U+=1/kappa*log(y+)+B

2)U+=1/kappa*log(E*y+)

these expressions are equivalent

seb62 January 8, 2009 12:07

thank you very much for your a
 
thank you very much for your answer,

Seb


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