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

Does RSM use wall function?

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

Reply
 
LinkBack Thread Tools Display Modes
Old   March 2, 2005, 02:09
Default Does RSM use wall function?
  #1
Sam
Guest
 
Posts: n/a
Hi,

Just have a quick question for LRR or SSG Reynolds stress models. Does these models use wall function to model the near wall flow? If so, we will need to consider the Yplus limit, right? If not, How can the near wall flow be modelled if RSM is used. Thanks for any comments here.
  Reply With Quote

Old   March 2, 2005, 04:37
Default Re: Does RSM use wall function?
  #2
Hrvoje Jasak
Guest
 
Posts: n/a
Yes, they need wall functions, with all the limitations that brings in. There are also some low-Re Reynolds stress models in literature, but I have never implemented one myself. Rumour is that they are very unstable/dificult to solve and don't give you the benefit you expect (but my news may be a generation behind the "latest and greatest").

Hrv
  Reply With Quote

Old   March 2, 2005, 19:31
Default Re: Does RSM use wall function?
  #3
Sam
Guest
 
Posts: n/a
Hi Hrvoje,

Thanks for your comment here. I recently run a case using a pretty fine mesh near the wall. No problem to converge if k-w/k-e model is used. When it comes to RSM, it just doesn't want to converge properly. I guess RSM is more sensitive to the Y+ value in this case ( I say so because when I increase the wall distance from first node, it does improve the convergence). Just wonder why.....
  Reply With Quote

Old   March 2, 2005, 22:53
Default Re: Does RSM use wall function?
  #4
JC
Guest
 
Posts: n/a
Hi,

I am not a turbulence modeling expert; however, a google on reynolds stresses and near wall showed the following:

It probably is what you want, and it comes from one of the big school in turbulence modeling:

http://personalpages.umist.ac.uk/sta...r/turbcfd2.pdf

Good luck, and let us know how it goes

JC..
  Reply With Quote

Old   March 3, 2005, 00:58
Default Re: Does RSM use wall function?
  #5
Sam
Guest
 
Posts: n/a
Hi Jc,

Thanks for the link. It's really handy.

I think there's some low-Re kw-RSM models available as well.... I'll try it out later...
  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
BlockMesh FOAM warning gaottino OpenFOAM Native Meshers: blockMesh 7 July 19, 2010 14:11
Problem with compile the setParabolicInlet ivanyao OpenFOAM Running, Solving & CFD 6 September 5, 2008 20:50
Problem with rhoSimpleFoam matteo_gautero OpenFOAM Running, Solving & CFD 0 February 28, 2008 07:51
Question about wall function Gary Main CFD Forum 1 December 3, 2007 11:54
Wall function problem in Fluent mefpz FLUENT 1 October 10, 2007 13:43


All times are GMT -4. The time now is 20:10.