Modelling of scattering of sound from trees by the PSTD method

Paper in proceeding, 2011

In an urban environment with multiple building façade reflections, scattering from trees will increase the diffusivity of the sound field and can lead to a reduction of the noise level. Here, the possibility to incorporate scattering objects as the trunk and branches of trees in the framework of an urban propagation model, the Fourier pseudospectral time-domain (PSTD) method, has been investigated. Two different modelling approaches are studied, with either a different density of the scattering objects or with the acoustic normal velocity components at the scattering boundaries and all acoustic components inside the scattering volumes equal to zero. The first PSTD scattering approach shows to work best, although some underestimation of levels is shown. The accuracy of modelling scattering from trees by using a coarser mesh is investigated.