Reflection of sound pulses from an inhomogeneous bubble medium

The effect of changes in the volume concentration of bubbles in the boundary zone of the bubble medium on the nature of reflection and radiation of the excited bubble medium is studied. The spectral characteristics of the radiation of a bubble medium are obtained at the initial stage of transition radiation and at large times when the radiation is stationary. It is shown that in the initial phase the emission spectrum is broadband and is located in the absorption band of the bubble medium, and at large times the emission spectrum is located outside this band.

Interaction of an acoustic wave with a multilayer medium containing a bubble liquid layer

Discrete-layered media are interesting to research since properties of each layer can significantly differ from near by ones and this can be used in technological processes. The presence of a small number of bubbles significantly increases the compressibility of the medium while the density of the bubble medium remains close to the density of the carrier liquid. From the applied point of view it is interesting that the energy of the incident wave can be completely absorbed by combining of layer properties (length, volume content of the dispersed phase, etc.). In this work, based on the equations of mechanics of dispersed media, we consider the reflection and propagation of acoustic waves passing at right angles through a three-layer medium in a pipeline containing a layer of bubble fluid. From the condition for the existence of a solution in the form of a decaying traveling wave, dispersion relations are written for each of the possible layers. Based on them, the dependences of the amplitude of the incident and transmitted waves on the propagation velocity of the pulse are analytically derived. The coefficients of reflection and transmission through the interface are obtained both in the general case and in particular cases for each layer. These ratios make it possible to calculate the possible consequences of a wave action on the considered media in the event of emergencies at work and to prevent them.

Propagation and interaction with obstructions of acoustic waves in vapor-gas-liquid media

Transmission and reflection of acoustic waves from a layer of a bubble medium into a liquid is theoretically studied, with subsequent reflection of the waves that arise from the rigid wall. The amplitudes of the emerging waves are determined through the amplitude of the initial wave, analytical expressions are obtained for the coefficients of reflection and transmission of waves across the interfaces.

The dynamics of a bubble cluster in a spherically symmetric acoustic field

A bubble cluster formed by gas bubbles and located in the center of a spherical bulb filled with liquid under the influence of pressure oscillations excited on the bulb wall was considered. The problem was solved numerically using the well-known model of bubble medium dynamics. It is shown that quasiperiodic modes of bubble and cluster oscillations can be established in sufficiently strong acoustic fields.