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

Yplus checking

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

Reply
 
LinkBack Thread Tools Display Modes
Old   March 28, 2008, 12:52
Default Yplus checking
  #1
Steven
Guest
 
Posts: n/a
Hi

Ive been running a simulation with K epsilon turbulence model and hence in cfx mesh have been defining an first layer thickness for inflation layer with a Yplus of 20 as it says in cfx help. When i plot a graph in post processing of Yplus vs x distance around the inflation layer (its a flat plate) most of the graph is above 20 on the upper surface but at the tip and tail the vlaue goes as low as 2. Id say about 85 % was above 15.

How can i change this or this acceptable? Im using 10 layers of inflation but due to aspect ratios and setting the internal angle to 15deg there is only 3-4 layers at the tips/tail

Thnaks

Steven
  Reply With Quote

Old   March 30, 2008, 18:55
Default Re: Yplus checking
  #2
Glenn Horrocks
Guest
 
Posts: n/a
Hi,

If you use the SST turbulence model then you can use automatic wall functions and therefore the range of y+ would be fine. Whether the y+ range you have with a k-eps model is a problem depends on the simulation. You will need to do a validation study to find out.

Glenn Horrocks
  Reply With Quote

Old   April 7, 2008, 09:29
Default Re: Yplus checking
  #3
Adam
Guest
 
Posts: n/a
Also, your y+ value is heavily dependent upon your local Reynolds number, so in areas with stagnated flow such as the leading edge, your y+ will automatically decrease

Adam
  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
critical error during installation of openfoam Fabio88 OpenFOAM Installation 21 June 2, 2010 04:01
Problems in compiling paraview in Suse 10.3 platform chiven OpenFOAM Installation 3 December 1, 2009 08:21
OpenFOAM installation problem on Linux 32bit kumar OpenFOAM Installation 0 April 27, 2007 06:41
Help%7e%7einstall openfoam13 on fc5%7e%7e aderliner OpenFOAM Installation 2 September 11, 2006 08:24
Gerris software installation mer Main CFD Forum 2 November 12, 2005 09:50


All times are GMT -4. The time now is 22:27.