FDTD Modelling of Sound Propagation in Air Including Viscothermal and Relaxation Effects
University of Edinburgh
Monday 7 December, 2020 from 16:30 to 16:50
in St Clair 2
Abstract:
Wave-based modelling has potential as a full bandwidth solution to virtual acoustic simulation, as opposed to traditional approaches based on geometric principle which are in general high-frequency approximations. While wave-based methods have traditionally been applied to low frequencies, their use in mid and high frequencies is becoming increasingly possible thanks to advances in high-performance and parallel computing. In such frequency ranges the effects of sound absorption in air become significant and cannot be neglected from simulations intended for auralization. In this paper, a system of equations relating to linear acoustics including viscothermal and relaxation effects in air is devised for the purposes of large-scale simulation of homogeneous urban/outdoor and indoor (room) acoustics, and for potential use in virtual reality. A discrete model is constructed for the free-space problem using finite-difference time-domain (FDTD) methods, which is validated through numerical simulations and comparisons against analytical models.