Acoustic Waves in Liquid with Gas Inclusions Having a Liquid Layer and a Viscoelastic Shell

In this study, a modified Rayleigh–Lamb equation is derived that takes into account the radial oscillations of a gas bubble covered with a viscoelastic shell and an inner thin liquid layer is distributed. For the case of small perturbations, a dispersion equation is found that takes into account the interfacial heat transfer between the gas, liquid layer, viscoelastic shell, and carrier fluid. An analytical expression for the equilibrium speed of sound is written out, and its dependence on the dimensions of the liquid layer, viscoelastic shell, and frequency of perturbations is established. The difference in the size of the inner liquid layer in shell bubble on the dynamics of acoustic waves is illustrated. The influence of the dependences of the shear modulus and viscosity of butyl rubber on the frequency of perturbations at different temperatures on the curves of the phase velocity and damping coefficient is shown. The theory is compared with the experimental data.