Sound propagation in periodic urban areas

摘要

This paper presents an experimental and numerical study of low frequency sound propagation in regular urban areas, under the assumption of a periodic distribution of buildings. Although the radiation losses above the urban canyons are generally significant, our results show that the effects of the periodicity still occur. Band diagrams are notably characterized, both numerically and experimentally, to investigate the effect of the radiation above the periodic structure. The problem is tackled using a coupled modal-finite elements method. The main idea is to turn the original unbounded domain into an equivalent waveguiding structure, with PML bounding the originally open region. The experimental study is performed in a scale model of urban area. Numerical and experimental results on both the band diagrams and the wavefield propagating through the lattice are in good agreement.