VELOCITY AND VORTICITY DISTRIBUTIONS OVER AN OSCILLATING AIRFOIL UNDER COMPRESSIBLE DYNAMIC STALL

THE velocity and vorticity fields around an oscillating airfoil in com pressible dynamic stall are reported. Phase averaged, two component la ser velocimetry data were obtained at a freestream Mach number of 0.3 and a reduced frequency of 0.05. This is the first set of velocity dat a available at a high Reynolds number (540,000) under compressible flo w conditions and it serves as a good database for development and vali dation of computer codes. Of particular interest is the formation of a separation bubble, which bursts coincidentally with the formation of the dynamic stall vortex, adding an extra degree of physical complexit y to the problem.