|
[Sponsors] |
December 5, 2008, 20:27 |
Hi,
I am trying to modify t
|
#1 |
Member
Daniel Harlacher
Join Date: Mar 2009
Location: Davis, CA, United States
Posts: 60
Rep Power: 17 |
Hi,
I am trying to modify the dissipation equation in the standard kEpsilon model. The problem is the following: The dissipation equation looks like this: // Dissipation equation tmp<fvscalarmatrix> epsEqn ( fvm::ddt(epsilon_) + fvm::div(phi_, epsilon_) - fvm::Sp(fvc::div(phi_), epsilon_) - fvm::laplacian(DepsilonEff(), epsilon_) == C1_*G*epsilon_/k_ - fvm::Sp(C2_*epsilon_/k_, epsilon_) ); Instead of C1 I want to put: fvScalarMatrix C1star = C1_+C1_*0.38*k_/epsilon_*1.0/(Gstar)*fvm::ddt(Gstar); but it complains - from my understanding the variable types are not compatible G looks like this: volScalarField G = nut_*2*magSqr(symm(fvc::grad(U_))); and Gstar: volScalarField Gstar = 0.5*magSqr(U_)+k_; Has anyone an idea how I can make them compatible ? - the problem was, that 'fvm::ddt(Gstar)' only works in a fvScalarMatrix for me. thanks - harly |
|
December 9, 2008, 09:07 |
Hi Harly!
Have a look at th
|
#2 |
Assistant Moderator
Bernhard Gschaider
Join Date: Mar 2009
Posts: 4,225
Rep Power: 51 |
Hi Harly!
Have a look at the programmers guide section 2.4 (especially page 36): in order to get a source term for another equation you have to use the explicit form of the differential operators (in your case that might be fvc::ddt) Bernhard
__________________
Note: I don't use "Friend"-feature on this forum out of principle. Ah. And by the way: I'm not on Facebook either. So don't be offended if I don't accept your invitation/friend request |
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Adding viscous dissipation term to energy equation | newbee | OpenFOAM Running, Solving & CFD | 6 | March 3, 2021 10:37 |
Modify the htc using UDF on NT | frederic | FLUENT | 1 | February 23, 2020 23:26 |
How to modify a value by a UDF? | jwt | FLUENT | 3 | May 23, 2003 12:01 |
how to modify model | wang | FLUENT | 1 | April 14, 2002 03:40 |
expansion of Hanjalic dissipation model of the RS equation | Ehab Haj-Qasem | Main CFD Forum | 0 | July 26, 1999 12:58 |