Reduction of tire road noise by acoustic absorption: Numerical evaluation of the pass-by noise level reduction using the normal incidence acoustic absorption coefficient

J. F. Hamet (1)

1 INRETS/LTE - Laboratoire Transport et Environnement

Comments: This report is an INRETS-LTE edition of the SILVIA -INRETS-013-WP2 report "Estimation of the attenuation of rolling noise by acoustic absorption", dated 19/09/2004. Summary: Part of INRETS task in the SILVIA project is to study the influence of the pavement characteristics on the generation and the propagation of road traffic noise using existing models. This work addresses the reduction of tire-road noise by absorption effects. It aims at finding a numerical correspondence between the two quantities generally available from measurements: pass-by noise noise levels at 7.5 m distance and acoustic absorption at normal incidence. Estimations are made using an omnidirectional point source for modeling the tyre, and the image method for modeling the reflection of the porous pavement. The approach is validated by comparing calculations to published experimental results. A numerical correspondence is found between the absorption coefficient in normal incidence and the pass by level difference obtained between a source over the absorbing surface and the source over a reflecting surface. The absorption and attenuation curves in function of frequency have similar shapes but are slightly shifted in frequency

Mots clés: tire road noise; acoustic absorption; noise reduction; mea- surement; modelling

Domaines: Acoustique [physics.class-ph]; Acoustique [physics.class-ph]

J. F. Hamet. Reduction of tire road noise by acoustic absorption: Numerical evaluation of the pass-by noise level reduction using the normal incidence acoustic absorption coefficient. 2004, 25p. ⟨hal-00546107⟩