Aircraft community noise prediction in 3D environments using Gaussian beam tracing

This work presents a novel noise propagation approach based on the Gaussian Beam Tracing (GBT) method that accounts for complex source directivity, weather conditions, and irregular ground topology for the evaluation of the noise footprint. The approach takes a precomputed noise sphere as input and propagates the acoustic pressure fluctuations through a moving inhomogeneous atmosphere over realistic three-dimensional (3D) terrain. Noise footprints, obtained with different source noise spheres and wind flow conditions, are compared. It is found that, in a quiescent atmosphere, a change in the source directivity results in a variation up to 15 dB on the acoustic footprint. In the presence of the mean flow, the variation in the noise footprint can reach up to 35 dB. The results suggest that any variation in the source directivity and wind flow can cause a significant change in the acoustic footprint predicted in 3D environments with varying terrain topology and wind flow.