CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

history effects of turbulence could u please..

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

LinkBack Thread Tools Display Modes
Old   May 22, 2006, 09:14
Default history effects of turbulence could u please..
Posts: n/a
It was mentioned in Jonas larson paper ' Two -Equation Turbulence Models For Turbine Blade Heat Transfer Simulations' that Navier stokes solver with algebriac turbulence models will give good results for simple cases but for cases with seperated regions ,shocks and high turbulence levels Navier stokes solver with transport turbulence models is good since it account for history effects .so , i want to know what is this history effect .
  Reply With Quote

Old   May 22, 2006, 13:42
Default Re: history effects of turbulence could u please..
Jonas Larsson
Posts: n/a
History effects in this context means that the turbulence in one point is dependent on the turbulence upstream of that point, ie what happened to the turbulent fluid before it reached the point, ie the history of the turbulence.

Algebraic models are local in the sence that they prescribe the turbulence in a point as a direct function of the local average flow-field in that point. Two-equation models account for history effects in the sence that they convect and diffuce both turbulent energy and a turbulent dissipation. So if you had something upstream that generated a lot of turbulence (like a separation) a two-equation model can account for this, whereas an algebraic model usually can't.
  Reply With Quote

Old   May 24, 2006, 01:14
Default Re: history effects of turbulence could u please..
Posts: n/a
Thanks Jonas the way of expressing is very precise and clear again thanking u for ur kind response ....regards bajjal

  Reply With Quote


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
Time history of turbulence intensity at one point trantoan2008 FLUENT 0 October 17, 2011 08:54
Turbulence postprocessing Mohsin FLUENT 0 September 19, 2011 21:05
Discussion: Reason of Turbulence!! Wen Long Main CFD Forum 3 May 15, 2009 09:52
Effects of turbulence on freesurface sek OpenFOAM Running, Solving & CFD 4 March 22, 2008 22:48

All times are GMT -4. The time now is 18:49.