The effect of Flow Speed and Angle of Attack on the Aerodynamic Noise of NACA 0012 Airfoil

Abstract

Wind energy is one of the main sources of renewable energy in the market today. The influence of the wind speed and the angle of attack on the aerodynamic noise was investigated in this study. Four different samples of airfoils were used. Three speeds (5, 10, 15 m/s) were employed. The results revealed that the aerodynamic noise was associated directly with the flow speed. The data showed that when the velocity increases by (5 m/s), the noise gets louder by an average amount of (10 dB). As the increase of flow velocity increased the velocity shear, this eventually increased the aerodynamic noise. As for the angle of attack, it had an effect on the aerodynamic noise as well. The results showed an increase in the overall sound pressure level between (1-4 dBA) when the angle of attack increased from (5 degrees) to (10 degrees), while there was an increase (1-6 dBA) when the angle of attack increased from (10 degrees) to (15 degrees). This study was conducted under subsonic flow condition and Reynolds number (3.3×104).