Sound field modeling in urban squares using a diffusion equation model

Abstract

A diffusion equation model which has been recently applied to room‐acoustic prediction is used to model the sound field in urban squares surrounded by diffusively reflecting building facades. A previous diffusion equation model [V. Valeau, et. al., J. Acoust. Soc. Am., 119, 2006, pp. 1504–1513; Y. Jing and N. Xiang, J. Acoust. Soc. Am. 121, 2007, pp. 3284–3287; A. Billon, et. al., Applied Acoustics, 2007, in print] is more suitable for room surfaces with low and medium absorption coefficient, whereas in this case the space is featured with an open top characterized by the absorption coefficient 1.0. Another diffusion equation model [T. Polles, et. al., J. Acoust. Soc. Am., 116, 2004, pp. 2969–2983] can well model the sound field in a space where one specific dimension is larger than the others, like street. However, it has not yet been extended for urban squares. A modified diffusion equation model is proposed for modeling the sound field in urban squares. Both simulations and scale‐model experiments are employed to investigate its effectiveness in terms of the reverberation time and sound pressure level distribution.