Nonlinearly propagating focused sound transmitted through solid plates.

Abstract

The transmission property of the fundamental and second harmonic components of the focused Gaussian beam incident on a solid plate put perpendicular to the acoustic axis has been investigated. In the present theory, the dependence of the transmission coefficient of plane wave on the incidence angle is applied to the fundamental and second harmonic pressures of the incident focusing beam, which has been decomposed in plane waves using Hankel transform. After the passage of the sound through the plate, the ensemble of plane waves is reconstructed to a beam, by means of the inverse Hankel transform. The nonlinear property which might exist in solid plates is neglected. The nonlinear propagation in the liquid is described by the Khokhlov-Zabolotskaya-Kuznetsov equation, which is solved under the successive approximation. The experiment for the 1.9-MHz focused sound transmitting through a silica glass or polystyrene plate immersed in water, and a methanol layer between two polystyrene plates, validates the present theory.