Computational Aeroacoustic Analysis of High Lift Devices in a Commercial Airliner

Abstract

Aircraft noise is one of the primary areas for aviation industry all around the globe. According to International Civil Aviation Organization ICAO, European aviation community has come together to work on improvement and abatement of aircraft noise. Due to e cient and quieter engines, airframe noise is major contributor for noise in commercial airliners. This noise is especially noticeable during landing and taking o . Airframe noise has 3 major contributors, slat noise, ap noise and landing gear noise. The trailing edge noise is caused due to the interaction of turbulence and the trailing edge, while the slat noise is due to the circulation in the slat gaps. This thesis is an analysis of airframe noise due to slat and ap in commercial airliners. Computational Aeroacoustic Analysis (CAA) is used, with a combination of DES and RANS. According to literature this technique makes the noise prediction a ordable and su ciently accurate. From the pressure uctuations along the surface, the far- eld acoustics are computed with Ffwoccs Williams Hawking FWH model in a commercial software Fluent by ANSYSR . TC12 three element high lift airfoil which is the airfoil pro le for Airbus A320 aircraft is used for the CFD and CAA. The analysis is done in three con gurations of the in nite wing in approach, take-o and landing con gurations with di erent deployment of high lift devices. The nal results indicate the dipole nature of noise produced by the wing. The OASPL values show that the noise produced is highly dependent on the de ection of slats and ap, where the major contribution is from leading edge slats.