E ect of Reduced Frequency on the Aerodynamic Behavior of an Airfoil Oscillating in a Plunging Motion


1 Department of Aerospace Engineering,Sharif University of Technology

2 Department of Mechanical Engineering,Sharif University of Technology


Abstract. A series of low speed wind tunnel tests were conducted to study the unsteady aerodynamic
behavior of an airfoil sinusoidally oscillating in plunge. The experiments included measuring the surface
pressure distribution over a range of reduced frequencies, k = 0:03 ???? 0:06. In addition, steady state data
were acquired and were used to furnish a baseline for further analysis and comparison. The model was
oscillated with amplitude of 15 cm and at three di erent mean angles of attack of 0, 10 and 18. The
unsteady aerodynamic loads were calculated from the surface pressure measurements, 64 ports, along the
chord for both upper and lower surfaces. The plunging displacements were transformed into the equivalent
angle of attack. Variations of the pressure coecients and aerodynamic loads with the equivalent angle
of attack showed strong sensitivity to the reduced frequency and mean angles of attack.