CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > General Forums > Main CFD Forum

derivation of epsilon equation of k-epsilon model

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 2, 2007, 20:32
Default derivation of epsilon equation of k-epsilon model
  #1
Ricardo Rezende
Guest
 
Posts: n/a
Does anybody have the deduction of the transport equation for the rate of dissipation of the k-epsilon model? I already deduced the equation for k but the equation for epsilon I am having difficulties. Can anybody help myself? Thanks!

  Reply With Quote

Old   April 3, 2007, 16:30
Default Re: derivation of epsilon equation of k-epsilon mo
  #2
Richard
Guest
 
Posts: n/a
Ricardo, You can find the complete epsilon equation in this paper

Rodi, W. and Mansour, N.N., Low Reynolds number kâ€"eps modelling with the aid of direct simulation data. J. Fluid Mech. 250 (1993) 509â€"529.

http://journals.cambridge.org/action...=-1&aid=339411

good luck! Richard
  Reply With Quote

Old   April 3, 2007, 17:07
Default Re: derivation of epsilon equation of k-epsilon mo
  #3
pennysworth
Guest
 
Posts: n/a
The epsilon equation that is used in the k-epsilon model is itself modelled after the k equation, because the exact equation is not useful from a modelling point of view. Thus, similar to the k equation, on has

D/Dt(eps) = Prod_eps + diffus_eps - destruct_ eps

Production is motivated by self-similar evolution of homogeneous shear turbulence. Destruction is motivated by self-similar decay of homogeneous turbulence, and diffusion is modelled in a gradient diffusion form just like diffusion of k.
  Reply With Quote

Old   April 5, 2007, 05:33
Default Re: derivation of epsilon equation of k-epsilon mo
  #4
p
Guest
 
Posts: n/a
i'll get it (hand written material)scanned and send you.
  Reply With Quote

Old   April 10, 2007, 14:11
Default Re: derivation of epsilon equation of k-epsilon mo
  #5
Ricardo Rezende
Guest
 
Posts: n/a
Thaks for all for your help.
  Reply With Quote

Old   May 1, 2007, 06:38
Default Re: derivation of epsilon equation of k-epsilon mo
  #6
Jane Hockey
Guest
 
Posts: n/a
I'm having trouble with this derivation as well. Turbulence is giving me grief because stats really isn't my strong point. If it's not too much trouble, would it be possible for me to take a look at the derivation as well?
  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
Calculation of the Governing Equations Mihail CFX 7 September 7, 2014 07:27
Derivation of Momentum Equation in Integral Form Demonwolf Main CFD Forum 2 October 29, 2009 20:53
Two-Phase Buoyant Flow Issue Miguel Baritto CFX 4 August 31, 2006 13:02
How to define Epsilon in RSM model? David FLUENT 0 March 17, 2004 10:39
Extra term in Epsilon equation Valdemir G. Ferreira Main CFD Forum 0 April 30, 2000 09:57


All times are GMT -4. The time now is 14:51.