Clarification of Inflow Turbulence Effect on Airfoil Flows and Airfoil Noise

Abstract

In this paper, surface pressure and NACA0012 airfoil flows are measured by wind tunnel test with inflow turbulence using the active turbulence generator (ATG) in order to clarify unsteady airfoil flows behavior contributed to airfoil noise under atmospheric turbulence. Turbulence intensity of the inflow can be changed from 10 % to 20 % and integral scale of the inflow set to 300 mm of 2 times chord length. The Reynolds number based on the chord length of the airfoil and flow velocity is 3.0×10⁵. As the results, short bubble generated on the suction surface seems to be disappeared by the inflow turbulence. Also, velocity profiles and spectra of surface pressure fluctuation and velocity fluctuation on the turbulent boundary layer on the suction surface cannot be seen effect by the inflow turbulence.