CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > ANSYS > CFX

Turbulence model choice

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

LinkBack Thread Tools Search this Thread Display Modes
Old   December 18, 2015, 12:54
Default Turbulence model choice
New Member
Join Date: Oct 2015
Posts: 3
Rep Power: 10
dave13 is on a distinguished road

I have a question regarding my choice of the turbulence model for my two-way FSI simulation as it seems to be not entirely correct.

I'm simulating flow through a channel (6x2.5x40mm) with a circular membrane (d=5mm) on the bottom which is inflated to give 15% strain. It's a steady state simulation with flowrates from 0.1 - 0.5 m/s.
At the inlet, I input a velocity profile from a previous solution with a longer geometry to have fully developed channel flow at the inlet. Additionally I specify the turbulent kinetic energy and dissipation at the inlet from this boundary condition profile (previous simulation with medium turbulence option). The flow is turbulent along the entire channel.

What we are interested in is the wall shear distribution on the membrane, so it is important that we get a correct result at the 'wall' (membrane) and apply the best turbulence model for that. I am though not sure if I am using the correct turbulence model as it seems to predict a too high wall shear compared to experimental data.

I used the SST model which to me seems most suitable for the case. I used it with the production limiter option (clip factor 10) because of stagnation points we get on the membrane and curvature correction (production correction factor 1.0). It does give similar results as with SST only (no advanced options), but slightly lower WSS. It predicts separation behind the membrane for all flowrates, unlike the k-e model (which does not give good near-wall results as expected though). I also tried to check the results with reynolds stress models, the BSL model confirmed the SST results whereas the SSG model gave similar results as the k-e model.

I am confused though as the SST model still seems to give too high wall shear values. Any inputs/suggestions what I did wrong, or which model you would apply?

Thanks a lot!

Last edited by dave13; January 10, 2016 at 11:02.
dave13 is offline   Reply With Quote

Old   December 22, 2015, 00:02
Senior Member
Bharath kumar
Join Date: Apr 2009
Posts: 169
Rep Power: 17
bharath is on a distinguished road
Hi dave
You are doing it right.Each turbulence model have its own advantages and also disadvantages.Which one you think right after your detailed analysis?
bharath is offline   Reply With Quote

Old   December 22, 2015, 04:42
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,727
Rep Power: 143
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
I would go back to basics here. I would ensure that your turbulence models can predict wall shear along a straight duct first. Then find a benchmark result which has a turbulent duct with a similar obstruction in it - hopefully you can find a case. You could use an airfoil blade boundary layer if you have to, but hopefully you can find something closer to your case. Once you see how the various turbulence models go on these benchmarks cases you can then approach your real case with more confidence.
ghorrocks is offline   Reply With Quote

Old   December 22, 2015, 07:12
New Member
Join Date: Oct 2015
Posts: 3
Rep Power: 10
dave13 is on a distinguished road
Thanks for your input! I will look into it.
dave13 is offline   Reply With Quote


channel flow, turbulence model

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
Use of k-epsilon and k-omega Models Jade M Main CFD Forum 40 January 27, 2023 07:18
Fluent :- turbulence Model prince_pahariaa FLUENT 9 May 20, 2016 03:41
Spalarat - Allmaras turbulence model saisanthoshm88 Main CFD Forum 1 June 16, 2014 16:33
Compressible turbulence model issues 351Cleveland OpenFOAM 5 October 24, 2013 15:41
Low Reynolds k-epsilon model YJZ ANSYS 1 August 20, 2010 13:57

All times are GMT -4. The time now is 15:02.