Airfoil trailing edge noise source location at low to moderate Reynolds number

Abstract

A study of the effects of Reynolds number and angle of attack on the dominant acoustic source location relative to the trailing edge for airfoils at low-to-moderate Reynolds number is presented. This study, which was performed using acoustic beamforming in an anechoic wind tunnel, helps assess the influence of each test parameter on the distance of the acoustic source from the trailing edge thus improving our knowledge of how airfoils produce tonal noise. The results show that the acoustic source location of a NACA0012 airfoil varies along the chord for the frequency range 500 Hz to 3000 Hz at low-to-moderate Reynolds number. Changing the angle of attack and Reynolds number resulted in small changes to the acoustic source location within this frequency range. A modified flat plate, which only radiated broadband noise under similar flow conditions, presented a scattered distribution of source location between the range 300 Hz to 1200 Hz.