Numerical simulations of the sound propagation in non rectilinear streets

At high frequencies, the sound propagation can be approximated by the propagation of sound particles which are reflected and absorbed at the boundaries. This propagation follows then a transport process. In urban canyons, this transport process can be reduced to a diffusion process. The resultant model allows one to obtain the spatial distribution of the acoustical energy in a street in a few seconds using a classical finite elements program. This diffusion model has been previously validated in rectilinear streets for different geometrical and acoustical parameters. In this paper, more complex geometries such as varying cross-sections, bents and streets crossings are dealt with. As the diffusion model only models the reverberated sound field, diffraction effects on the direct sound field at streets corners are added. The obtained results are then compared to scale model experiments.