A theoretical study of serrated leading edges in aerofoil and vortical gust interaction noise

Abstract

Serrated leading edges are one of the most promising passive aerodynamic control methods for the reduction of aerofoil-turbulence interaction noise. To elucidate the possible physical mechanisms, the current paper studies the simplified setup with aerofoil-vortical gust interaction and proposes an analytical model by incorporating Fourier transform into the Wiener-Hopf method. The proposed model suggests that the serrations operate on the incident vortical gusts as convolution, which leads to the innovative concept that models serrations as transfer functions in the wavenumber domain. Overall, the current theoretical study could provide a unique insight of the inherent aerodynamic noise control mechanisms of leading-edge serrations.

A Study of High Lift Aerodynamic Devices on Commercial Aircrafts

“…From Figure 6(a) the overall sound pressure level is high between the leading edge slat and main element but the peak sound level of 135dB is seen in slat cove region. It must be noted that noise emission of vented leadingedge slat airfoil is high due to interaction of vortex-gust with surface of airfoil and found to be more compared to sealed slat case (Huang, 2019). At the trailing edge of slat the sound pressure level can reach up to 111dB.…”

Variations with Mach number for gust–airfoil interaction noise

“…Zhong et al 20 proposed useful corrections to the flat-plate solution to account for the effect of nonuniform mean flows of real airfoils. Huang 21 developed an analytical model by incorporating Fourier transform into the Wiener-Hopf method to elucidate the possible physical mechanisms. Celik et al 22 performed a comprehensive mapping of wall-pressure fluctuations over an airfoil under different inflow conditions, including a grid-generated turbulent inflow.…”