Acoustic Waves in a Liquid with Gas Bubbles Covered by a Viscoelastic Shell

Abstract

The propagation of acoustic waves in a mixture of a liquid with gas bubbles encapsulated with a viscoelastic shell is investigated. The system of differential equations of the disturbed motion of the mixture is given and the dispersion relation is derived. Low-frequency asymptotics of the phase velocity and attenuation coefficient are obtained. The dependence of the equilibrium speed of sound on the perturbation frequency and the dimension of encapsulated bubbles is established and illustrated. The theory is compared with available experimental data.