
[Sponsors] 
July 14, 2012, 20:25 
A question about UEqn sonicFoam

#1 
Member

Hi, I have a question about the UEqn implemented into sonicFoam, the code of the UEqn is:
Code:
fvVectorMatrix UEqn ( fvm::ddt(rho, U) + fvm::div(phi, U) + turbulence>divDevRhoReff(U) ); Code:
tmp<fvVectorMatrix> kEpsilon::divDevRhoReff(volVectorField& U) const { return (  fvm::laplacian(muEff(), U)  fvc::div(muEff()*dev2(fvc::grad(U)().T())) ); } but after examining the definition of dev2 in src/OpenFOAM/primitives/Tensor/TensorI.H I found the following: is the rateofstrain tensor given by but according to the definition of DivDevRhoReff And manipulating the expression (1) I conclude that the term Code:
+ turbulence>divDevRhoReff(U) If someone can help me with my confusion about this term, I was very thankful
__________________
Felipe G Last edited by lfgmarc; July 15, 2012 at 14:34. 

January 24, 2013, 13:26 

#2 
Senior Member
Join Date: Jul 2011
Posts: 101
Rep Power: 6 
Quote:
I hope I can find out what is wrong. 

February 15, 2013, 10:07 

#3 
Senior Member
Jens Klostermann
Join Date: Mar 2009
Posts: 117
Rep Power: 8 

June 14, 2013, 15:36 

#4 
Senior Member
Sasan Ghomi
Join Date: Sep 2012
Location: Iran  Tehran
Posts: 185
Rep Power: 5 

June 17, 2013, 09:57 

#5 
Senior Member
Jens Klostermann
Join Date: Mar 2009
Posts: 117
Rep Power: 8 
No, I didn't habe time to work further on this problem.


December 24, 2014, 16:48 

#6  
Senior Member
Dongyue Li
Join Date: Jun 2012
Location: Torino, Italy
Posts: 700
Rep Power: 8 
Quote:


February 1, 2015, 17:49 

#7 
New Member
Panagiotis Giannatselis
Join Date: Jan 2015
Location: Athens, Greece
Posts: 5
Rep Power: 2 
Reading Calculating divDevReff I concluded that this term is zero if the fluid is incompressible and near convergence it doesn't concern us. The term remains for stability reasons when we are still far from the solution. If somebody more experienced confirms my thinking, the problem is solved.
I don't feel able to tell you that my point is 100% correct. 

Thread Tools  
Display Modes  


Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
solving the momentum equation in UEqn.  callahance  OpenFOAM  2  October 18, 2012 09:38 
Question Re Engineering Data Source  imnull  ANSYS  0  March 5, 2012 14:51 
one question about turbulence + Ueqn ?  lfgmarc  OpenFOAM Programming & Development  0  October 25, 2011 10:57 
internal field question  PitzDaily Case  atareen64  OpenFOAM Running, Solving & CFD  2  January 26, 2011 16:26 
Poisson Solver question  Suresh  Main CFD Forum  3  August 12, 2005 04:37 