PRESSURE DISTRIBUTION ON AN AIRFOIL IN OSCILLATING FLOW.

The effect of oscillating flow on the pressure distribution of a symmetrical airfoil was investigated experimentally employing a remote pressure transducer. An open circuit wind tunnel utilizing rotating shutter blades downstream of the test section was used to create oscillating flow. Tests were run at two frequencies, as well as at steady flow, and three angles of attack. The mean and unsteady pressure characteristics were recorded from which mean values of the normal force were determined. The results indicate that an airfoil at high angle of attack will produce more lift in oscillating flow than in steady flow. Author