Experimental Investigation of High-Lift Device Aerodynamic Noise Reduction Using Structured Porous Trailing-Edge Flaps

Aerodynamic noise from high-lift devices remains a key obstacle for the next-generation supersonic aircraft to return to commercial service. This study investigates the use of structured porous trailing-edge flaps as a passive control method to reduce the aerodynamic noise of the high-lift device. Acoustic wind tunnel tests were conducted to systematically assess the effects of pore size, pore coverage, pore spacing, and pore position on the noise reduction performance. The results show that structured porous trailing-edge flaps can effectively reduce the noise produced by high-lift devices. Configurations with medium pore size (Dh=0.8 mm), smaller chordwise and spanwise pore spacing (Ch=2 mm, Sh=2 mm), and larger pore coverage provided the best noise reduction, consistently reducing the overall sound pressure level (OASPL) of the high-lift device across all the studied freestream velocities, including a reduction of approximately 1.74 dB at V∞=60 m/s.