Hi, I am validating the aerodynamic coefficinets of airfoils from FLUENT against experimental data. Test conditions of mach 0.35 at chord Re of 6.0 million are used. With the three airfoils that i have tested, FLUENT over predicts the Clmax in all cases where the onset of flow seperation is not accurately captured (is overpredicted). I am using the k-w SST model with two fluid zones given that the BL tranistion point is known from the experimental data. How can i rectify the over estimation of Clmax???? (I believe it could be my BC's..in particular the inelt turbulence intesity factor...however i am not sure what a suitable value is...) Thanks heaps

Unfortunately your experience is quite common (and expected based on the published literature) for the class of turbulence model you are using. The Reynolds Stress Model available in Fluent may provide improved predictions, but it is much less robust. The use of LES may also give better results.