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

eddy viscosity

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 3, 2006, 16:03
Default eddy viscosity
  #1
Mike
Guest
 
Posts: n/a
Hi all,

I have one more question. The cfx manual states that eddy viscosity should be of the order of 1000 times the dynamic viscosity for a fully turbulent flow. I am checking the values of eddy viscosity in the domain and it varies 0-300 times to dynamic viscosity. How does this affect the results? So if most part of the domain is not fully turbulent what happens? any help would be very much appreciated.

Mike
  Reply With Quote

Old   April 4, 2006, 13:12
Default Re: eddy viscosity
  #2
Robin
Guest
 
Posts: n/a
Hi Mike,

It's hard to say exactly what the effect will be. Most Turbulence models are created by making some simplifying assumptions about the Reynolds averaged flow. These assumptions may no longer apply.

See how your results compare when you run laminar flow. You could also try the SST transition model, although I suggest reviewing the documentation carefully to ensure its applicability as well.

Regards, Robin
  Reply With Quote

Reply


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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Boussinesq eddy viscosity assumption siw Main CFD Forum 2 February 17, 2011 12:30
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
Question about eddy viscosity ratio limit Piti CFX 2 January 17, 2008 16:49
Vertical eddy viscosity in channal flow? Liu Main CFD Forum 0 June 15, 2004 21:07


All times are GMT -4. The time now is 07:37.