CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM

Near Wall treatment

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 11, 2009, 19:32
Default Near Wall treatment
  #1
Member
 
Sven Winkler
Join Date: May 2009
Posts: 70
Rep Power: 17
sven is on a distinguished road
I am using OpenFOAM to calculate a turbulent channel flow with a Reynolds Stress Model using wall functions. Since my results are not quite what they should be, I am interested how OpenFOAM deals with the near wall region, because I think this could be the course for my bad results. So, my questions are:
  1. In which file can I find how the near wall region is treated?
  2. I am especially interested in how the velocity gradient for the cell next to the wall is calculated (which order, with which values), where can I find this?
  3. Where can I get more information on how the wall Functions in OpenFOAM work?
Thanks a lot!
sven is offline   Reply With Quote

Old   September 13, 2009, 21:57
Default
  #2
Member
 
Sven Winkler
Join Date: May 2009
Posts: 70
Rep Power: 17
sven is on a distinguished road
I found out that the gradient at the wall is somehow defined in fvPatchField.C. In the source Code of this file, it says:

Code:
// Return gradient at boundary                                                      
template<class Type>
Foam::tmp<Foam::Field<Type> > Foam::fvPatchField<Type>::snGrad() const
{
    return (*this - patchInternalField())*patch_.deltaCoeffs();
}
and I also found the declaration of deltaCoeffs() in the file fvPatch.H:

Code:
//- Return the face - cell distance coeffient                                       
            //  except for coupled patches for which the cell-centre
            //  to coupled-cell-centre distance coeffient is returned
            const scalarField& deltaCoeffs() const;
Unfortunately I do not really understand how the gradient at the boundary is calculated. Does anyone understand this source code and cann tell me how the gradient is calculated?
sven is offline   Reply With Quote

Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
[Commercial meshers] Fluent3DMeshToFoam simvun OpenFOAM Meshing & Mesh Conversion 50 January 19, 2020 16:33
LES wall treatment Valerio FLUENT 0 April 26, 2008 08:12
Errors running allwmake in OpenFOAM141dev with WM_COMPILE_OPTION%3ddebug unoder OpenFOAM Installation 11 January 30, 2008 21:30
RSM with enhanced wall treatment zwdi FLUENT 1 April 24, 2005 21:36
Multicomponent fluid Andrea CFX 2 October 11, 2004 06:12


All times are GMT -4. The time now is 04:38.