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

Turb. Kin. Energy - Interpretation ?

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

Reply
 
LinkBack Thread Tools Display Modes
Old   June 19, 2009, 04:22
Default Turb. Kin. Energy - Interpretation ?
  #1
New Member
 
Join Date: Jun 2009
Posts: 5
Rep Power: 8
Daniel is on a distinguished road
Greetings,

I want to present some results of my simulation for my Master thesis. At the moment i am looking for some physical Term to describe the Turbulence of my Flow (not reynolds Number). So is the Turb. Kin. Energy a good Value for this or are there any other usefull physical Terms (Eddy Freq. etc. ) ?
Daniel is offline   Reply With Quote

Old   June 19, 2009, 07:07
Default
  #2
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,954
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
Hi,

Sounds like you need a good turbulence modelling textbook. I cna recommend "Turbulence Modelling for CFD" by Wilcox.

In short - turbulence is usually characterised by two variables. The first is usually the intensity expressed as turbulence kinetic energy, and the second can be any of turbulence dissipation, turbulence frequency or turbulent length scales (there are also more obscure second variables but these are the most widely used ones). Of the second variables, all the different types are all linked by correlations after some assumptions are made (eg isotropy) so if you have one you can derive any of the others.

Glenn Horrocks
ghorrocks is offline   Reply With Quote

Old   June 20, 2009, 04:06
Default
  #3
New Member
 
Join Date: Jun 2009
Posts: 5
Rep Power: 8
Daniel is on a distinguished road
thanks glenn,

do you mean with the term "turbulence dissipation" the conversion of the kin turb. energy to heat energy ? or how can i understand it.

i am sorry, i have no more time for any deep literture, and i present the results also to people which know basics of fluid mechanics, but they are not specialiced in it. i just need a term or terms for describing how intense my turbulence is at a certain location. so i think, as a first guess to show the tubrulence kin. energy should be the right choice.
Daniel is offline   Reply With Quote

Old   June 20, 2009, 07:04
Default
  #4
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 10,954
Rep Power: 85
ghorrocks has a spectacular aura aboutghorrocks has a spectacular aura aboutghorrocks has a spectacular aura about
Hi,

"Deep literature"? I have told you exactly what book to look at! Just go to the library and pick it up. I am not going to write an explanation of turbulence modelling on the forum, that's why they write textbooks on it. I think your last comment is right - if you don't understand the term then don't use it.

Glenn Horrocks
ghorrocks 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
ATTENTION! Reliability problems in CFX 5.7 Joseph CFX 14 April 20, 2010 15:45
energy in sonicFoam joern OpenFOAM Running, Solving & CFD 0 June 16, 2009 15:53
Boundary Conditions for Turb. Energy + Dissipation sebastian Main CFD Forum 0 May 5, 2008 03:32
SIMPLE and energy equation convergence Fabio Main CFD Forum 0 June 1, 2007 06:06
Turb. Kinetic energy john FLUENT 1 March 20, 2006 13:57


All times are GMT -4. The time now is 11:12.