Effects of dynamic viscoelastic properties on acoustic diffraction by a solid sphere submerged in a viscous fluid (Q1403059)

This study provides a general analysis for scattering of a planar monochromatic compressional sound wave by a homogeneous isotropic viscoelastic solid sphere immersed in an unbounded viscous heat-nonconducting compressible fluid. The dynamic viscoelastic properties of the spherical scatterer and the viscosity of the surrounding fluid are rigorously taken into account. Havriliak-Negami model for viscoelastic material behaviour along with appropriate wave-harmonic field expansions and pertinent boundary conditions are employed to develop a closed-form solution in form of infinite series. Subsequently, the associated acoustic quantities such as the scattered far-field pressure directivity pattern, scattered intensity distribution, differential scattering cross-section, and the acoustic radiation force are evaluated for given sets of viscoelastic material properties. Numerical results clearly indicate that, in addition to the traditional fluid viscosity related mechanisms, the dynamic viscoelastic properties of the solid obstacle can be of major significance in sound scattering. Limiting cases are examined, and fair agreements with well-known solutions are established.