CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > OpenFOAM

fvm::laplacian appropriate for d/dx(d/dy)

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Search this Thread Display Modes
Old   August 11, 2009, 22:40
Default fvm::laplacian appropriate for d/dx(d/dy)
Sven Winkler
Join Date: May 2009
Posts: 70
Rep Power: 13
sven is on a distinguished road

I am currently working on understanding the source code of the LaunderGibsonRSTM model.

In this model the Reynolds Stress equation reads:

tmp<fvSymmTensorMatrix> REqn
      + fvm::div(phi_, R_)
      - fvm::Sp(fvc::div(phi_), R_)
    //- fvm::laplacian(Cs*(k_/epsilon_)*R_, R_)
      - fvm::laplacian(DREff(), R_)
      + fvm::Sp(Clg1_*epsilon_/k_, R_)
      + (2.0/3.0*(Clg1_ - 1)*I)*epsilon_
      - Clg2_*dev(P)

        // wall reflection terms
      + symm
            I*((yr_.n() & reflect) & yr_.n())
          - 1.5*(yr_.n()*(reflect & yr_.n())
          + (yr_.n() & reflect)*yr_.n())
        )*pow(Cmu_, 0.75)*pow(k_, 1.5)/(kappa_*yr_*epsilon_)
My question now concerns the forth term from the top:

 //- fvm::laplacian(Cs*(k_/epsilon_)*R_, R_)
This term seems to represent a part of the diffusion of the turbulent reynolds stresses. However, in all books on turbulence this equation looks like d/dx(Cs*k/epsilon*R*dR/dy), where d/dx and d/dy are derivatives in different directions.

Is it possible to translate this term into OpenFOAM source Code by using the fvm::laplacian scheme, even though the two derivatives (d/dx,d/dy) have different directions?
sven is offline   Reply With Quote

Old   December 10, 2009, 13:24
New Member
xiang chai
Join Date: Aug 2009
Posts: 13
Rep Power: 13
chai is on a distinguished road
Hi, Sven
I am facing a similar problem. Did you find a solution to your problem?
chai is offline   Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
Question about fvmlaplacian operator cosimobianchini OpenFOAM Running, Solving & CFD 0 February 1, 2007 14:40

All times are GMT -4. The time now is 15:25.