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

Turbulence modelling in CFD

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

Reply
 
LinkBack Thread Tools Display Modes
Old   September 2, 2002, 21:13
Default Turbulence modelling in CFD
  #1
Fabian
Guest
 
Posts: n/a
I am a final year undergraduate student at university, and am doing my thesis on the numerical modelling of a 2-Stroke Engine using CFD-ACE.

I have sucessfully modelled 3D laminar flow, and now am looking to model turbulent flow. The problem is that i don't have any values for K and D (epsilon), to input into the simulation.

I am seeking help from anyone who has even approximate values for K and D that i can use as a starting point for the turbulent modelling of this simulation.

Any help that could be offered would be greatly appreciated.

Cheers
  Reply With Quote

Old   September 6, 2002, 08:52
Default Re: Turbulence modelling in CFD
  #2
vinod
Guest
 
Posts: n/a
as far as i know the general practice to take K is 0.5* times the free stream kinetic energy. i.e 0.5* uinfty**2 but for D(epsilon) it can give some high value, say 30000 or so.

  Reply With Quote

Old   September 10, 2002, 10:12
Default Re: Turbulence modelling in CFD
  #3
Tim
Guest
 
Posts: n/a
For K & E value at inlet I use:

K = 1.5 * (I*Uin)^2

E = (k^1.5)/characteristic length

I is some turbulence intensity (varies from case to case) - try 0.05 for a start

Tim
  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
ASME CFD Symposium - Call for Papers Chris Kleijn Main CFD Forum 0 September 25, 2001 10:17
ASME CFD Symposium Chris Kleijn Main CFD Forum 0 August 22, 2001 06:41
CFD Design...The CFD Future John C. Chien Main CFD Forum 19 October 6, 1999 11:57
Turbulence Intensity Vs CFD Simulation Apple L S Chan Main CFD Forum 3 December 15, 1998 18:28
SMARTFIRE: A new interactive fire field modelling CFD code. John Ewer Main CFD Forum 0 July 7, 1998 03:46


All times are GMT -4. The time now is 10:12.