Aerodynamic Characteristics of an Airfoil in Periodic Gusts : Effects of Separation Bubble's Behavior on Airfoil Performance

Abstract

The effects of periodic gusts on the performance of an airfoil are investigated. Periodic gusts were generated by the movement of a row of cylinders crossing in front of an airfoil. Total pressure loss, unsteady pressure distribution on the airfoil surface and velocity fluctuation were measured. The airfoil investigated here has a separation bubble on its suction surface, which increases total pressure loss even if the angle of attack is small. But as either frequency or solidity of cylinders increases, the separation bubble tends to disappear, followed by recovery of total pressure.