CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > Siemens > STAR-CCM+

Transition Models Help

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

LinkBack Thread Tools Search this Thread Display Modes
Old   September 22, 2011, 15:57
Default Transition Models Help
New Member
Paul Nardone
Join Date: Sep 2011
Location: Lawrence KS
Posts: 3
Rep Power: 14
paulnardone is on a distinguished road
hello folks out there in cd-adapco land.

My name is Paul and I'm working on my graduate research project. The basic Idea behind this project is to model "Bypass" transition along a flat plate (the plate being similar to a turbine blade).

I know there are 2 transition models in the Star-CCM+ product which are

1. The Gamma Re-Theta model, and
2. The Turbulence Suppression model.

Does anyone have any advice on which of these to use or are they both useless for this case since such a transition is not typical. (hence why we are studying it). I'm able to get them both to work but I'm not sure if they are outputting the correct answers yet.

Beyond this if any one out there has experience with modeling Transition especially "bypass" transition feel free to contact me with information.

thank you

Paul Nardone Jr
University of Idaho, Idaho Falls
Nuclear Engineering Department
paulnardone is offline   Reply With Quote

Old   September 22, 2011, 17:45
Senior Member
Join Date: Oct 2009
Location: Germany
Posts: 636
Rep Power: 21
abdul099 is on a distinguished road
I'm not sure what you mean by "Bypass transition". But for the Gamm Re Theta model, you will need a huge number of prism layers.

Regarding to the user guide, the turbulence suppresion model is not a true transition model:
"The Turbulence Suppression model allows the user to mimic the effect of transition by suppressing the turbulence in a certain pre-defined region. Since it does not have a predictive capability, it is arguably not a true transition model."
Should be self-explaining.
abdul099 is offline   Reply With Quote

Old   September 22, 2011, 19:16
New Member
Paul Nardone
Join Date: Sep 2011
Location: Lawrence KS
Posts: 3
Rep Power: 14
paulnardone is on a distinguished road
Hey thanks for your response. I assumed that the turb. suppression was no good as you mentioned because it wasn't a true transition model.

I'm currently running a Gamma Re Theta model and I did apply a more significant prism layer... 30 layers over a 2 cm boundry layer with a 1.2 cell growth rate. I'm running my model locally with 8-gigs or ram so I didnt want to go too crazy with the mesh (700,000 cells currently)... but my solution blew up... so I think I need to adapt my mesh and a few other parameters.

when I said "bypass" transition I meant that transition from a laminar to turbulent state is prematurely onset primarily due to strong free stream turbulence...

it's definitely a doosie of a problem for me

thanks again for your response and if you have any more advice on the matter I'll definitely take it into consideration

paulnardone is offline   Reply With Quote


bypass, model, transition

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Transition Turbulence Models Apurva Main CFD Forum 3 September 7, 2018 05:48
Ansys 12, Fluent, SST Transition models bugra FLUENT 9 February 8, 2016 01:57
Issue with transition models k.vimalakanthan CFX 1 April 26, 2011 22:15
Fluent 12.1 - transition viscous models kdrbrk FLUENT 4 July 29, 2010 11:34
Code release: Flow Transition and Turbulence Chaoqun Liu Main CFD Forum 0 September 26, 2008 17:15

All times are GMT -4. The time now is 21:49.