The lift and drag characteristics and associated flowfields over the suction surface of an NACA 0015 airfoil with an aspect ratio of 2.90 were obtained at a Reynolds number of 250,000 for conditions both with and without freestream turbulence (FST). Increasing the FST from 0.25 to 9 % resulted in an increase in peak lift coefficient of 30 % with no measurable change in the slope of the lift coefficient CL vs the curve of the angle of attack alpha; no significant change in drag coefficient CD at each alpha occurred. Oil flow visualization results showed an elimination of the laminar separation bubble with FST, corresponding to a disappearance of the hysteresis loop in the performance data; a significant delay in separation was also shown for the case with FST, corresponding to the increase in peak lift coefficient. The results present engineers with information for the design of a wide variety of system where airfoils experience FST.
Effects of freestream turbulence on the performance characteristics of an airfoil
Einflüsse der Freistrahlturbulenz auf die Leistungscharakteristiken des Tragflügels
AIAA Journal ; 29 , 9 ; 1353-1354
1991
2 Seiten, 5 Bilder, 2 Quellen
Article (Journal)
English