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

wall function and grid independency?????

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

Reply
 
LinkBack Thread Tools Display Modes
Old   October 22, 2006, 07:42
Default wall function and grid independency?????
  #1
scott
Guest
 
Posts: n/a
I am new ,very new I have question about turbulence modeling and mesh independency.

I am using k-epsilon and wall functions to resolve the flow. Now I have to optimize the mesh for my case. 1-when the wall function is valide? i read the manual and i I didn't understand: i follow y+ or y star

2-How can I attin the grid independency ? 3- y+ satisfated imply that i have an independent mesh est regards

  Reply With Quote

Old   October 23, 2006, 08:47
Default Re: wall function and grid independency?????
  #2
Ralf Schmidt
Guest
 
Posts: n/a
http://www.cfd-online.com/Forum/flue...cgi?read=42778
  Reply With Quote

Old   October 23, 2006, 17:25
Default Re: wall function and grid independency?????
  #3
scott
Guest
 
Posts: n/a
i read the help but i haven't understand
  Reply With Quote

Old   October 26, 2006, 12:31
Default Re: wall function and grid independency?????
  #4
hugo
Guest
 
Posts: n/a
When the wall function is valide?,

When the normal stresses are negligible. for example in straight ducts.

In curve ducts like a 90 degrees bend, the normal stresses are important and the wall function is not correct.

if you use wall function you need to check the Y plus and in this case the Y plus must be close 20 or 30

if you don't use wall function Y plus must be close 1

  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
wall function and grid Y FLUENT 3 March 17, 2005 07:48
wall function and grid dependency Bob Main CFD Forum 10 April 28, 2004 02:15
Onera Wing Wall function? Dianhong Main CFD Forum 0 November 21, 2003 21:19
Grid Independent Solution Chuck Leakeas Main CFD Forum 2 May 26, 2000 11:18
Wall function in adverse pressure gradients stephane baralon Main CFD Forum 11 September 2, 1999 04:05


All times are GMT -4. The time now is 19:57.