# Problem in applying Gamma-Retheta transition model

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

November 6, 2012, 23:10
Problem in applying Gamma-Retheta transition model
#1
Senior Member

Mehdi
Join Date: Jan 2011
Location: Iran
Posts: 130
Rep Power: 6
dear friends;
hi, I face the problem in applying Gamma-Retheta transition model in my code. in fact, it started to converge, but after 2000 iteration, its results are not correct. as you can see figures, Cf is not correct and it should match with analytical turbulent Cf on flat plate after transition to turbulent regime.
I think the problem stems from the velocity profile, as you can see in second figure, velocity profile near flat plate doesn't have turbulent velocity profile shape. in fact, it is similar to Laminar profile and even the shape of the flow that face with adverse pressure gradient.
I guess problem comes from the intermittency equation. next figure shows intermittency in where above velocity profile was taken.
and amazingly, as you can see in K profile in next figure, code does not work and it has very strange shape.

I don't know why this happens. I have tried to find the reason of the problem, but I can not find any thing. the initial and boundary conditions for this case are :

Reynolds Number= 752536.0

Rmu (mut/mu)= 6
Tui in inlet= 3.1% , Tui in leading edge= 1.99%

Attached Images
 friction coef..jpg (21.1 KB, 9 views) velocity.jpg (51.4 KB, 8 views) intermittency.jpg (64.4 KB, 8 views) Kinetic Energy.jpg (22.2 KB, 6 views)
__________________
Best Regards;
Mehdi
E-mail: mb.pejvak[at]Gmail[dot]com

 November 6, 2012, 23:48 #2 Senior Member   Mehdi Join Date: Jan 2011 Location: Iran Posts: 130 Rep Power: 6 I should mentioned that I used Malan et al. and menter (2009) empirical correlation formula for Flength and critical momentum thickness Re and non of them provide good results. __________________ Best Regards; Mehdi E-mail: mb.pejvak[at]Gmail[dot]com

 November 13, 2012, 11:27 #3 Senior Member   Mehdi Join Date: Jan 2011 Location: Iran Posts: 130 Rep Power: 6 any idea which can fix the problem? __________________ Best Regards; Mehdi E-mail: mb.pejvak[at]Gmail[dot]com

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post msrinath80 OpenFOAM Running, Solving & CFD 18 March 3, 2015 06:36 johnp FLUENT 6 November 13, 2014 05:40 dhrubo CFX 3 June 5, 2010 05:32 pablo FLUENT 0 August 7, 2006 15:44 Srinivas Main CFD Forum 1 November 7, 2005 15:16

All times are GMT -4. The time now is 01:59.