Flap Noise Simulations and Flyover Measurements of a Full-Scale A320 Aircraft

In this work, flap noise collectively refers to aeroacoustic effects caused by a full flap setting of an A320 aircraft during a landing approach phase. The relative importance of these sources can be assessed from beamform maps, where one of the main challenges is to accurately capture the exact source location and strength for a flying aircraft. There are also difficulties on a model scale, where scaled down geometries may produce unexpected relative noise differences and some prominent sources may not contribute on a small scale. Thus, an experiment was set up in the AWB wind tunnel, where a realistic large-scale isolated flap side-edge was tested, which in this study serves as a benchmark for verification and validation of simulations. For the proof of concept, our method of choice is a cut-cell wall-modelled Large Eddy Simulation (LES) implemented in the form of hydrodynamic/acoustic splitting (HAS) in the commercial MGLET solver. It is then used to validate an advanced stochastics-based zonal modelling approach, where a Forced Linear Advection Diffusion (FLAD) transport equation is solved in 3D on top of a high-quality RANS simulation. Finally, the stochastics-based flap noise simulations are performed for a full-scale Airbus A320 in landing configuration. The comparisons of simulated source regions and the corresponding beamform maps obtained from experiments are presented and discussed.