Sound Attenuation In A Coarse Granular Medium

Abstract In order to investigate the deviation of the spherical particle model from practical granular media in nature, the sound attenuation in a kind of water-saturated riverbed coarse sand was measured in the high frequency range 40-600 kHz. The results reveal that the rough surface and non-spherical shape factors of the sand particles have strong effects on the acoustic attenuation under experimental conditions in which β R is greater than 60 in the whole frequency range and in which k R is not far less than 1 when the frequency is higher than 300 or 400 kHz, where β is the viscous wavenumber, k is the compressional wavenumber and R is the average radius of the sand particles.