SOUND-ATTENUATION IN A COARSE GRANULAR MEDIUM

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 βR̄ is greater than 60 in the whole frequency range and in which kR̄ 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 R̄ is the average radius of the sand particles. © 1993 Academic Press Limited.