Using Acoustic Diffusors to Reduce Noise in Urban Areas
Résumé
The use of acoustic diffusors to reduce noise in urban areas is investigated by computer simulation. The numerical simulations have been performed with a sound particles tracing based code, which allows to model the sound reflection, diffusion and absorption by building façades with any arrangement of acoustic diffusors. Several parameters have been studied, among which, the diffusion pattern, the relative surface on the façades, the arrangement and the size of diffusors. In addition, the combined effect of absorption and diffusion by diffusors has also been investigated. The numerical results show that a significant noise reduction can be observed on the sound attenuation as well as on the sound decay in a street, by considering diffusors creating uniform diffusion, with a relative surface larger than 20 %, and if possible locating on the lower part of the façades. Lastly, and as expected, by adding sound absorption on diffusors, it increases the noise reduction.