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

default values of kOmega (Wilcox) different from paper

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   July 26, 2011, 09:04
Default default values of kOmega (Wilcox) different from paper
  #1
Senior Member
 
romant's Avatar
 
Roman Thiele
Join Date: Aug 2009
Location: Eindhoven, NL
Posts: 374
Rep Power: 21
romant is on a distinguished road
Hej,

does anyone know why the default values for the k omega model by Wilcox from 1988, which is implemented into OpenFOAM are different from the ones that the paper suggests.

alpha = 5/9 in the paper but 13/25 in OpenFOAM (it is also 13/25 in the 2006 version of the model, which adds a cross diffusion term and a stress delimiter)

beta = 3/40=0.075 in the paper, but 0.072 in OpenFOAM (in the 2006 model, this term is modelled by the stress delimiter modification).

The paper is http://adsabs.harvard.edu/abs/1988AIAAJ..26.1299W
__________________
~roman
romant is offline   Reply With Quote

Old   August 2, 2011, 11:39
Default
  #2
Senior Member
 
Dave
Join Date: Jul 2010
Posts: 100
Rep Power: 16
daveatstyacht is on a distinguished road
roman,
The beta of 0.072 is equivalent to the beta0 of the 1998 version of k-w on the NASA langley turbulence page for k-w: http://turbmodels.larc.nasa.gov/wilcox.html . This beta0 term is then multiplied by (1+70*chiomega)/(1+80*chiomega) to form beta. Note that term differs from the 2006 version as well. I have not looked at the code for the k-w model in OpenFOAM to see which formulation has been implemented but both of those cofficients match those of the 98' formulation.
Regards,
Dave
daveatstyacht is offline   Reply With Quote

Old   August 3, 2011, 06:43
Default
  #3
Senior Member
 
romant's Avatar
 
Roman Thiele
Join Date: Aug 2009
Location: Eindhoven, NL
Posts: 374
Rep Power: 21
romant is on a distinguished road
Quote:
Originally Posted by daveatstyacht View Post
roman,
The beta of 0.072 is equivalent to the beta0 of the 1998 version of k-w on the NASA langley turbulence page for k-w: http://turbmodels.larc.nasa.gov/wilcox.html . This beta0 term is then multiplied by (1+70*chiomega)/(1+80*chiomega) to form beta. Note that term differs from the 2006 version as well. I have not looked at the code for the k-w model in OpenFOAM to see which formulation has been implemented but both of those cofficients match those of the 98' formulation.
Regards,
Dave

Thank you, I think I will check with the NASA website and see if the terms correspond to the model as well.
__________________
~roman
romant is offline   Reply With Quote

Reply

Tags
komega, turbulence modelling

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
Ensight - node values -cell values leo FLUENT 1 May 12, 2010 08:47
How to reference paper which is in review Zonexo Main CFD Forum 4 June 10, 2008 23:13
Changing default values dcwnj CFX 1 February 6, 2008 15:46
cfx default values for coeffients of k-e model Mike CFX 2 August 1, 2006 09:56
cfx default values for coeffients of k-e model Mike CFX 0 July 25, 2006 09:50


All times are GMT -4. The time now is 03:10.