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

How can check the eddy viscosity at the wall with LES

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

Reply
 
LinkBack Thread Tools Display Modes
Old   August 14, 2015, 02:21
Default How can check the eddy viscosity at the wall with LES
  #1
New Member
 
Sungjin Won
Join Date: Dec 2012
Location: Seoul/Republic of Korea
Posts: 9
Rep Power: 5
sjwon1991 is on a distinguished road
Hi, I checked my code based on 3D turbulent channel flow model (Re_tau=180).

Staggered grid which contains eddy viscosity at the center of grid is used.

Due to the properties are placed on the grid center, I confused about checking the properties of eddy viscosity at the wall. When I plot the time averaged eddy viscosity data, the tendency doesn't look like going to zero.

The data starts from y+ = 0.583690705381331.

Thanks in advance.
Attached Images
File Type: jpg eddy viscosity.jpg (33.5 KB, 20 views)
sjwon1991 is offline   Reply With Quote

Old   August 14, 2015, 07:57
Default
  #2
Senior Member
 
Filippo Maria Denaro
Join Date: Jul 2010
Posts: 2,693
Rep Power: 33
FMDenaro will become famous soon enoughFMDenaro will become famous soon enough
The static Smagorinsky eddy viscosity model cannot give zero at wall...
Usually, a dumping function is supplied
FMDenaro is offline   Reply With Quote

Old   August 16, 2015, 04:38
Default
  #3
New Member
 
Sungjin Won
Join Date: Dec 2012
Location: Seoul/Republic of Korea
Posts: 9
Rep Power: 5
sjwon1991 is on a distinguished road
Quote:
Originally Posted by FMDenaro View Post
The static Smagorinsky eddy viscosity model cannot give zero at wall...
Usually, a dumping function is supplied
Thank you for replying!

As you said, static Smagorinsky eddy viscosity cannot give zero at wall.

But when if I wanna check the dynamic eddy viscosity, is there a way to check it?
sjwon1991 is offline   Reply With Quote

Old   August 16, 2015, 04:47
Default
  #4
Senior Member
 
Filippo Maria Denaro
Join Date: Jul 2010
Posts: 2,693
Rep Power: 33
FMDenaro will become famous soon enoughFMDenaro will become famous soon enough
Quote:
Originally Posted by sjwon1991 View Post
Thank you for replying!

As you said, static Smagorinsky eddy viscosity cannot give zero at wall.

But when if I wanna check the dynamic eddy viscosity, is there a way to check it?
in the dynamic procedure, the eddy viscosity function must go to zero at a wall, you can check by looking to the vertical profiles as you did in the previous figure
FMDenaro 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
Divergence in AMG solver! marina FLUENT 15 August 9, 2016 20:15
Problem with divergence TDK FLUENT 11 July 31, 2016 06:03
Wall modeling in LES chivaee Main CFD Forum 1 May 31, 2012 15:34
Constant Eddy Viscosity faisal_durr Main CFD Forum 0 February 15, 2012 06:53
Multicomponent fluid Andrea CFX 2 October 11, 2004 05:12


All times are GMT -4. The time now is 00:29.