Audio-frequency surface wave characteristics above porous and comb-like surfaces

Attenborough, Keith and Taherzadeh, Shahram (2022). Audio-frequency surface wave characteristics above porous and comb-like surfaces. In: Proceedings: Internoise 2022.

URL: https://internoise2022.org/programme/

Abstract

Near grazing incidence, the sound field due to point sources over porous or comb-like boundaries can include an airborne surface wave. Analytical expressions for the phase and group speeds of this surface wave are obtained using (i) a thin air layer approximation for the impedance of a comb-like surface, (ii) two approximate models for the acoustical properties of porous media and (iii) a model for a surface consisting of identical parallel slanted slits above a hard plane. Comparisons of model predictions indicate that the approximate model, derived initially to predict the acoustical properties of porous asphalt, is the least accurate. Predictions of surface wave attenuation and group velocity are compared with data obtained over arrays of parallel aluminium strips.

Viewing alternatives

Item Actions

Export

You can export this page using these formats