Spherical oscillations of encapsulated microbubbles: Effect of shell compressibility and anisotropy

We introduce a model that describes spherical oscillations of encapsulated microbubbles in an unbounded surrounding fluid. A Rayleigh–Plesset-like equation is derived by coupling the Navier–Stokes fluid dynamics with Navier solid via internal/external boundary conditions. While previous models were restricted to incompressible isotropic shells, shell modeled here as compressible viscoelastic material and then generalized anisotropic material. The exact value resonance frequency calculated analytically, damping constant computed approximation weak damping. correction widely used Church for shells evidenced, effects compressibility anisotropy are discussed.