An experimental and numerical investigation of the sound distribution in street canyons with non-parallel building façades

Abstract

In this paper the sound distribution in a street canyon is investigated both experimentally and numerically. The sound field inside a 1:4 scaled down model of a street canyon has been investigated. A line source was used as sound source in order to generate steady cylindrical wave propagation. The sound distribution on the façades were mapped in the frequency domain and previously presented as contour plots. In order to validate the measurements, two-dimensional numerical simulations were conducted using COMSOL Multiphysics software, which uses a finite element approximation method. A cross-section at the centre of the scale model was chosen to be compared with the 2D simulation results. The comparison showed reasonable agreement, especially for frequencies starting at 1000Hz and up. The experimental data was expressed in 1/24 octave band frequency, while the simulated data was a single narrowband frequency. In order to get a better agreement for frequencies below 1000Hz more simulated data has been generated and is presented in this paper. Furthermore, initial results of 3D simulations are presented, as well as the impulse response of the street canyon model.