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

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.