Experimental study on airfoil noise reduction with trailing edge serrations under various incoming flow conditions

Abstract

An experimental investigation of airfoil trailing edge noise reduction at Reynolds number of 2.76 × 105–4.31 × 105 was conducted within the attack angle of −10°–10° using the trailing edge serrations. An unequally spaced linear microphone array was used to identify the sound source around the airfoil. The results show that trailing edge serrations can effectively reduce airfoil trailing edge noise under various incoming flow conditions. The noise reduction effect varies with incoming flow condition and a maximum noise reduction of about 6 dB is observed. The noise reduction effect is more obvious under negative attack angles. For a specified serration configuration, there is an optimal velocity range for noise reduction.