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

Energy equation in OpenFoam

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 23, 2014, 22:35
Default Energy equation in OpenFoam
  #1
Member
 
Kan
Join Date: Feb 2014
Location: Australia
Posts: 54
Rep Power: 12
nwpukaka is on a distinguished road
Dear OpenFoamer,

I have a question regarding the energy equation in rhoSimpleFoam. see code:

fvm::div(phi, h)
- fvm::Sp(fvc::div(phi), h)
- fvm::laplacian(turbulence->alphaEff(), h)
==
- fvc::div(phi, 0.5*magSqr(U), "div(phi,K)")

I think this energy equation written in enthalpy has missed viscous related term, is that right? because I use this solver to simulate a shear driven flow, but the temperature increase is small compared to experiment results.

If I am right, how can I add this viscous related term to my energy equation?

Thank you!
Kan
nwpukaka is offline   Reply With Quote

Old   June 24, 2014, 00:34
Default
  #2
Member
 
Kan
Join Date: Feb 2014
Location: Australia
Posts: 54
Rep Power: 12
nwpukaka is on a distinguished road
I've included this stresses term to energy equation, see below:

(1)
volTensorField gradU = fvc::grad(Urel);
(2)
volTensorField tauEff = turbulence->muEff()*(gradU + gradU.T()) + turbulence->muEff()*dev2(T(fvc::grad(Urel)));
(3)
- (tauEff && gradU)

The second point is the code for stresses term in energy equation. I saw this from #18

http://www.cfd-online.com/Forums/ope...-equation.html

I don't quite understand this code: turbulence->muEff()*dev2(T(fvc::grad(Urel)))? can anyone explain this?

Thank you!
Kan
nwpukaka is offline   Reply With Quote

Old   June 24, 2014, 03:40
Default
  #3
Member
 
Kan
Join Date: Feb 2014
Location: Australia
Posts: 54
Rep Power: 12
nwpukaka is on a distinguished road
volTensorField tauEff = turbulence->muEff()*(gradU + gradU.T()) + turbulence->muEff()*dev2(T(fvc::grad(Urel)))
this term is for stress term.

I am just curious that why the compressible solver in OpenFoam didn't consider this term in energy equation?
nwpukaka 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
Pyrolisis energy equation yaqb OpenFOAM Programming & Development 0 May 22, 2014 18:25
Wave Action Equation Solver for OpenFOAM chyczewski OpenFOAM Programming & Development 7 September 4, 2013 12:06
error message cuteapathy CFX 14 March 20, 2012 07:45
New OpenFOAM Forum Structure jola OpenFOAM 2 October 19, 2011 07:55
SIMPLE and energy equation convergence Fabio Main CFD Forum 0 June 1, 2007 07:06


All times are GMT -4. The time now is 22:18.