Towards Realistic Simulations of Sound Radiation by Moving Sources in Outdoor Environments

Abstract

PACS numbers:43.28.Js, 43.28.En, 43.20.El A time-domain solver of the linearized Euler equations is used to study outdoor propagation of acoustic waves generated by broadband moving sources. For that, high-order schemes, developed initially in the computational aeroacoustics community, are employed. A time-domain impedance boundary condition recently proposed in the literature is implemented to deal with reflexion of acoustic waves over the ground. In addition, curvilinear coordinates are used to account for topographic effects. First, test cases show that long range sound propagation and diffraction by obstacles in three-dimensional geometries are accurately determined. Simulation of the acoustic radiation by a broadband monopole source moving above a perfectly reflecting plane is then considered. Numerical results are satisfactorily compared to those obtained from an analytical solution. At last, the case of a broadband source moving above a non-flat terrain, with an inhomogeneous impedance ground, is investigated. The effects of a topography defect on the acoustic field are examined.