Sand acoustics: The effective density fluid model, Pierce/Carey expressions, and inferences for porous media modeling

• Published in: The Journal of the Acoustical Society of America Vol. 125; no. 4; p. EL164
• Main Author: Williams, Kevin L
• Format: Journal Article
• Language: English
• Published: United States 01.04.2009
• ISSN: 1520-8524
• DOI: 10.1121/1.3097681

Recently, Pierce and Carey [J. Acoust. Soc. Am. 124, EL308-EL312 (2008)] presented a low frequency analysis of sound propagation in sand/silty sediments. Here, equivalent expressions are presented using a low frequency expansion of an unconsolidated version of Biot porous medium theory. The resulting expression for attenuation allows identification of the non-dimensional parameter beta in the Pierce/Carey result in terms of physical parameters. The agreement of these two derivations motivates further analyses. The results imply that porous media propagation models that treat the medium's inertia via a single component approximation disregard a fundamental physical effect resulting from the relative inertia of the grains and fluid and are thus incomplete.