J. Phys. II France
Volume 7, Numéro 4, April 1997
Page(s) 637 - 647
DOI: 10.1051/jp2:1997148
J. Phys. II France 7 (1997) 637-647

Effective Medium Model for Ultrasonic Attenuation Due to the Thermo-Elastic Effect in Concentrated Emulsions

Y. Hemar, N. Herrmann, P. Lemaréchal, R. Hocquart and F. Lequeux

Laboratoire d'Ultrasons et de Dynamique des Fluides Complexes Unité de Recherche Associée au CNRS ${\rm n}^\circ$851, Université Louis Pasteur, 4 rue Blaise Pascal, 67070 Strasbourg Cedex, France

(Received 3 October 1996, revised 19 November 1996, accepted 3 January 1997)

In this article, we deal with the propagation of ultrasonic waves in monodisperse concentrated oil-in-water emulsions. Using the approximation of Isakovich, we propose two different models, a mirror model and a core-shell model, aiming to describe the temperature field in the dense medium and to supply a correct expression of the ultrasonic wave vector. The comparison between experimental data and theoretical models shows that the core-shell model leads to a very accurate description of the ultrasonic attenuation, in a wide range of frequencies and concentrations, in the case where the thermo-elastic effect, due to the scattering of thermal waves by the particles, is the dominant loss mechanism.

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