The formation of nonlinear sound fields in the boundary region of the bubble medium

Abstract

The formation of sound fields in the boundary region of a bubble medium under the influence of a powerful sound pulse for different volume concentrations of bubbles is studied. Two characteristic ranges of the volume concentration of bubbles, to the limits of which different types of wave fields are formed, are determined. At low values of volume concentrations in the boundary region, a long-lived space-limited standing sound wave is formed. A standing sound wave contains an order of magnitude more energy than other areas of the bubble medium. At large values of the volume concentration of bubbles in the boundary region of the bubble medium, an excitation zone forms. The structure of the zone is a periodic wave propagating deep into the bubble medium. The wavelength in the excitation zone increases with increasing distance from the boundary.