Noise Emission from the Flap Profile of a Two-Element 30P30N High-Lift Airfoil

An aeroacoustic characterization of the two-element 30P30N high-lift airfoil configuration without the slat was performed in the UTIAS hybrid anechoic wind tunnel. This study utilized particle image velocimetry (PIV), remote surface microphones, and phased microphone array measurements to investigate the unsteady loading and flow features responsible for the broadband noise prevalent in turbulent flows over such wing models. The results indicate that the mean surface loading in the flap region is largely insensitive to variations in angle of attack, suggesting minimal variation in broadband noise with loading. Surface pressure fluctuations reveal distinctive patterns around the flap cove, leading edge, and main element trailing edge, highlighting these regions as primary sources of flap noise. Source localization maps further confirm the dominance of noise around the flap cove and leading edge. Moreover, instantaneous vorticity profiles and turbulent kinetic energy acquired from PIV measurements enrich the understanding of the mechanisms underpinning noise generation. The study advances our knowledge of flap noise generation mechanisms and lays the groundwork for improved physics-based models of the noise source in the flap region of high-lift device