Optimisation et test de la géométrie de la dentelure du bord de fuite des plaques planes pour réduire le bruit propre aux ailes

With an expanding network of transportation and the use of air traffic, noise radiated from civil aircraft during takeoff and landing have become a major concern to communities nearby airports. The objective of this work is to investigate the reduction of turbulent boundary layer-trailing edge (TBL-TE) interaction noise. In order to test the concept of noise reduction, the required experimental setup is designed and created. The first part of this study focuses on developing an aeroacoustic wind tunnel test section at Carleton University. The test section walls have been acoustically treated to simulate an acoustically far-field environment with forwarding flight. The two sides of the wind tunnel test section are fitted with anechoic chambers and lined with acoustic transparency tensioned cloth screens which act as an interface between the test section and the anechoic chambers to provide a smooth flow surface while eliminating the need for a jet catcher and reducing interference effects. The ability of the trailing edge serrations to reduce TBL-TE noise is first analyzed through numerical optimization study, and trailing edges are after tested in a wind tunnel. Three different serration geometries are investigated. The noise spectra were modelled using Howe semi-empirical model for a semi-infinite flat plate, at zero angles of attack and low Mach number. NACA 0012 airfoil and flat-plate trailing edges are analyzed and tested. The results of the optimization studies are used to examine the influence of serration design parameters. It is shown that the sawtooth serrated trailing edges yield greater noise reductions than slitted and sinusoidal serrated trailing edges. Experimental and optimization results are then compared. It is concluded that numerical and experimental results are in agreement showing that optimized serrated trailing edge configurations can yield less TBL-TE noise compared to the traditional straight-trailing edge configuration.