Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.
A series of low speed wind tunnel tests were conducted to study the unsteady flow events on an airfoil oscillating in plunge mode beyond its static-stall angle of attack. Data were acquired at a Reynolds number of 0.42*106, over a range of reduced frequencies, k=0.03-0.1 and plunging amplitude of ±15cm. It was found that in the post stall region, there existed a fully separated flow over the upper surface of the airfoil and the dynamic stall vortex formed in the vicinity of the leading edge region. Also, the effect of the reduced frequency was investigated.