title: Eccentricity effects on acoustic radiation from a spherical source suspended within a thermoviscous fluid sphere.
abstract: Acoustic radiation from a spherical source undergoing angularly periodic axisymmetric harmonic surface vibrations while eccentrically suspended within a thermoviscous fluid sphere, which is immersed in a viscous thermally conducting unbounded fluid medium, is analyzed in an exact fashion. The formulation uses the appropriate wave-harmonic field expansions along with the translational addition theorem for spherical wave functions and the relevant boundary conditions to develop a closed-form solution in form of infinite series. The analytical results are illustrated with a numerical example in which the vibrating source is eccentrically positioned within a chemical fluid sphere submerged in water. The modal acoustic radiation impedance load on the source and the radiated far-field pressure are evaluated and discussed for representative values of the parameters characterizing the system. The proposed model can lead to a better understanding of dynamic response of an underwater acoustic lens. It is equally applicable in miniature transducer analysis and design with applications in medical ultrasonics.
authors.affiliation: Department of Mechanical Engineering, Iran University of Science and Technology, Narmak, Tehran 16844, Iran. hashemi@iust.ac.ir
authors.forename: Seyyed M
authors.initials: SM
authors.lastname: Hasheminejad
authors.forename: Mahdi
authors.initials: M
authors.lastname: Azarpeyvand