wall functions.-E value, epsilon calculation
I am reading through the wall functions code for OF and comparing it with fluent and I noticed some strange things:
1- For the value E instead of using 9.781 as fluent 9 is used.
2- When OF calculates the epsilon for the wall function uses the following formula:
epsilon_[faceCelli] +=Cmu75*pow(k_[faceCelli], 1.5)/(kappa_.value()*RASModel::y_[patchi][facei]);
In Fluent the same formula is used but what is bothering me is the faceCelli term. In fluent epsilon_ is calculated at the point (epsilonp), however, in OF the term epsilon_[faceCelli] seems to refer to the value at the wall.
Thank you in advance,
I'm also interested how OF is dealing with the wall functions.
So far I'm not really deep in it but about the E thing I found out that they overwriting the E=9 to E=9.8 in the respective turbulence Model with this autoCreateEpsilon (-Nut etc.) function.
I am also interested in OpenFOAM deals with wall functions. In which file did you find the
equation epsilon_[faceCelli] +=Cmu75*pow(k_[faceCelli], 1.5)/(kappa_.value()*RASModel::y_[patchi][facei]); you mention in 2.? Thanks a lot!
On this note of the epsilonWallFunction, does anybody know the source of the formulation mentioned above by Sven? I wish to know the reasoning behind why epsilon @ the first node near wall is recalculated this way.
If anyone can direct me to the scientific article, which forms the basis of the epsilonWallFunction, I would be grateful. Thanks.
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