CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Pre-Processing

k-epsilon or k-omega or other models which is more appropriate for internal flow?

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

Like Tree1Likes
  • 1 Post By jola

Reply
 
LinkBack Thread Tools Display Modes
Old   May 17, 2013, 00:57
Default k-epsilon or k-omega or other models which is more appropriate for internal flow?
  #1
Senior Member
 
immortality's Avatar
 
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,174
Rep Power: 16
immortality is on a distinguished road
in an internal flow with walls,inlet and outlet which model is more suitable for including both free stream outside of the boundary layer and also near the wall in the boundary layer so that can capture near wall phenomena the best?
Suggestions are appreciated.
__________________
Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King.
To Be or Not To Be,Thats the Question!
The Only Stupid Question Is the One that Goes Unasked.
immortality is offline   Reply With Quote

Old   May 17, 2013, 02:49
Default
  #2
Administrator
 
jola's Avatar
 
Jonas Larsson
Join Date: Jan 2009
Location: Gothenburg, Sweden
Posts: 157
Rep Power: 10
jola is on a distinguished road
Send a message via MSN to jola Send a message via Skype™ to jola
Experts disagree. There is no clear concensus on this. We use SST k-omega for some applications, where secondary flows are strong and a model that is extra conservative for separation predictions is needed. For other applications we user a realizable k-epsilon model, which is easier to work with, converges better and is most often also conservative for separation (not always though)
immortality likes this.

Last edited by jola; May 17, 2013 at 03:22.
jola is offline   Reply With Quote

Old   May 17, 2013, 07:10
Default
  #3
Senior Member
 
immortality's Avatar
 
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,174
Rep Power: 16
immortality is on a distinguished road
thank you Mr.Larsson
1)If i want to use realizable k-epsilon model how should i treat in the mesh?
I have regions of separation.should i fine the mesh til y+<1 or its sufficinet to be bigger and arround 30?
2)does realizable k-epsilon has an automatic function like kOmegaSST into itself that change to wall function near the wall when 30<y+<60?
Thank you so much.
__________________
Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King.
To Be or Not To Be,Thats the Question!
The Only Stupid Question Is the One that Goes Unasked.
immortality is offline   Reply With Quote

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
reversed flow during RNG in turbulence-k epsilon Suman Kandula FLUENT 4 April 2, 2012 07:12
Standard K Epsilon and Transitional SST models Robin FLUENT 1 January 17, 2010 19:06
SimpleFoam k and epsilon bounded nedved OpenFOAM Running, Solving & CFD 1 November 25, 2008 21:21
justification of the form models of Omega dali Main CFD Forum 0 March 25, 2005 05:11
computation about flow around a yawed cone Tylor Xie Main CFD Forum 0 June 9, 1999 07:33


All times are GMT -4. The time now is 13:20.