Modelling the acoustic performance of a noise barrier with a quasi-periodic boundary condition

Two dimensional numerical models are often used to estimate the environmental noise attenuation of a road-side barrier. The prediction of noise barrier attenuation using a two dimensional boundary element model assumes a coherent line source and an infinitely long barrier with constant cross-section. However, for point sources and barrier geometries that do not have constant cross section in the third dimension, three dimensional models must be used to obtain more accurate predictions of noise reduction due to the barrier. Furthermore, in a three dimensional model, radiation in all directions can be considered. In this study, the acoustic performance of noise barriers in three dimensions is predicted using a quasi-periodic boundary element method. Results from both analytical and finite element models of the noise barrier are also obtained and compared with numerical results from the quasi-periodic boundary element model. Good agreement between the results obtained from all three approaches is observed.