ATTENUATION OF SOUND IN HIGHLY CONCENTRATED SUSPENSIONS AND EMULSIONS

The absorption of sound in emulsions and suspensions is due to viscous and thermal transport processes occurring at the interface of the nonhomogeneities, as well as to the intrinsic absorption in the materials comprising the system. For highly concentrated mixtures, multiple scattering is shown to play an important role. Following the arguments of Waterman and Truell [J. Math. Phys. 2, 512 (1961)], the behavior of the scattering medium may be specified explicitly in terms of the number of scatterers per unit volume, and the farfield amplitude f(θ) obtained for a single scatterer. The coefficients of f(0) for a single scatterer have been calculated by Allegra and Hawley [J. Acoust. Soc. Am. 51, 1545 (1972)] for systems of solid and fluid particles suspended in a fluid media. © 1979, American Institute of Physics. All rights reserved.