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

Boussinesq eddy viscosity assumption

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

Reply
 
LinkBack Thread Tools Display Modes
Old   February 17, 2011, 09:25
Default Boussinesq eddy viscosity assumption
  #1
siw
Senior Member
 
Stuart
Join Date: Jul 2009
Location: Portsmouth, England
Posts: 432
Rep Power: 12
siw is on a distinguished road
Hi,

The Boussinesq eddy viscosity assumption is given at:

http://www.cfd-online.com/Wiki/Bouss...ity_assumption

where the Reynolds stress tensor contains the fluctuating components of the velocity components when they are Reynolds decomposed (http://www.cfd-online.com/Wiki/Reynolds_averaging).

My questions are:

1. Are the terms on the Right-Hand Side of the equation the instantaneous velocity, density and kinetic energy?

2. Would the eddy viscosity assumption be different if the Reynolds stress tensor contained fluctuating components of the velocity components when they are Favre decomposed (http://www.cfd-online.com/Wiki/Favre_averaging)?

I cannot find these answers anywhere.

Thanks
siw is offline   Reply With Quote

Old   February 17, 2011, 09:58
Default Hi
  #2
Member
 
Dynampally Pavitran
Join Date: Mar 2010
Location: India
Posts: 72
Rep Power: 6
pavitran is on a distinguished road
  1. They are average values not instantaneous.
  2. I guess the eddy viscosity assumption may not be different when the are favre decomposed.
pavitran is offline   Reply With Quote

Old   February 17, 2011, 12:30
Default
  #3
siw
Senior Member
 
Stuart
Join Date: Jul 2009
Location: Portsmouth, England
Posts: 432
Rep Power: 12
siw is on a distinguished road
Thanks for the reply.

Please can anyone explain the case for question 2?
siw 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
Eddy Viscosity Transport Model Jade M Main CFD Forum 0 April 21, 2010 14:17
Link between eddy viscosity and subgrid-scale turbulent viscosity in LES Marvin Main CFD Forum 6 December 4, 2009 11:08
Boussinesq Assumption tstorm FLUENT 3 October 26, 2009 06:11
Question about eddy viscosity ratio limit Piti CFX 2 January 17, 2008 16:49
eddy viscosity Mike CFX 1 April 4, 2006 13:12


All times are GMT -4. The time now is 03:16.