Momentum coefficient of airfoil flow
 

Hi all,

studying some papers about the calculation of airfoil flow I have got the impression that standard k-eps model with wall function is not suitable at all for that case. Especially when it comes near the stall angle. Even low-re versions of k-eps model do not give accurate results because separation on the suction side is surpressed often. Could someone tell if my impressions concerning that topic are rigth ? Improvement was shown by using k-w models because separation is better captured. Could one also expect improvement when using k-w model with wall functions ? In papers the improvement is mostly shown on the values of cd and ca. Does someone know if I can expect the same improvement for the momentum coeficient ?

Any comment on that are appreciated !

Marat

Re: Momentum coefficient of airfoil flow
 

Hi,

You're right, RANS models often fail to predict the stall angle.

The Wilkox's k-omega model seems to give better prediction in some case as other model like the Spalart-Almars's one equation model. I think there was an Ercoftac Workshop one or two days ago, organized by TUdelft, where one of the test case was an Aerospatial-A airofoil at 13.3 degre. At this angle a recirculating flow appears on the suction surface and most of the usual turbulent models don't predict it.

I'm not sure that the k-omega turbulence model was design to be used with wall function.

Sylvain

momentum coefficient
 

Hi
Is the momentum coefficient with power coefficient to calculate the relationship?How can be calculated.
please help me...
thank you.:)