CFD Online Logo CFD Online URL
Home > Forums > FLUENT

low reynolds airfoil simulation

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

LinkBack Thread Tools Display Modes
Old   March 1, 2010, 16:30
Default low reynolds airfoil simulation
New Member
Join Date: Jan 2010
Posts: 11
Rep Power: 9
miguel.soto is on a distinguished road
Sponsored Links
Hello everybody

Im trying to simulate low reynolds airfoil flow. The Re number is about 4*10^5, and the goal is to get the airfoil polar, drag against lift curve. I try to do that using k-epsilon viscous model, and y+=1,by means of a boundary layer, but the polar differs to much from the experimental one.

Could you please tell me wich viscous model would be the appropiate for that kind of simulations. I heard that some people uses michel criterion or e^n models, to calculate the transition point between laminar and turbulent, using user-defined functions. Others say that spalart-allmaras is the best one for low reynolds.

Best Regards
miguel.soto is offline   Reply With Quote
Sponsored Links

Old   March 1, 2010, 19:09
Join Date: Oct 2009
Posts: 30
Rep Power: 9
thanos is on a distinguished road
hi! i use the spalart-almaras, it gives an accurate Cl for the angles of attack before stall but i can not have good results in stall angle. Also the Cd diverges a lot from the experimental values.
Is there anything common between mine and yours results?
thanos is offline   Reply With Quote

Old   March 3, 2010, 09:59
New Member
Stefano UniCT
Join Date: Feb 2010
Posts: 4
Rep Power: 9
StefaCT is on a distinguished road
try the SST transitional model (4 equations model) findable in fluent 12.0.
Be careful on the Turbulent Intensity and Turbulent Viscosity Ratio values that you will put in the boundary conditions. You should find better agreement using low turbulent values with high AoA and high turbulent values with low AoA.
However stalled AoA is very difficult to simulate with RANS steady models, you have to try Unsteady RANS models or better DES model with SST-Kw to obtain better results.
StefaCT is offline   Reply With Quote

Old   March 3, 2010, 14:51
New Member
Join Date: Jan 2010
Posts: 11
Rep Power: 9
miguel.soto is on a distinguished road
I dont mind about stall values, im only worried about having more accurate cd vs cl values outside the stall threshold.

But, is this k-omega SST turbulent model different from the 2 equations SST at fluent 6.2? Perhaps it incorporate added equations to evaluate transition between laminar and turbulent.

miguel.soto is offline   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
Turbulence model for low Reynolds number flow? Nokadu Main CFD Forum 3 May 26, 2013 11:42
Solver settings-GMO-rotating coupled motion-very low reynolds no. doctsh FLOW-3D 1 February 15, 2010 23:42
Fluent 12.0, Low Reynolds Number Flows anandvksin2003 FLUENT 1 January 26, 2010 06:16
calculating drag at low Re no over FX airfoil M. Essuri FLUENT 1 November 1, 2006 16:55
Low Reynolds number airfoil. Pablo Cornejo FLUENT 14 October 19, 2005 09:41

Sponsored Links

All times are GMT -4. The time now is 11:05.