Acoustic Manifestations of a Gas Inclusion Near an Interface

The study continues previous investigations based on the use of specific (bispherical) coordinates in describing the behavior of bubbles in the presence of bounding surfaces. Explicit dependences of the first oscillation modes and the scattered field on bubble size, distance to the boundary, and physical parameters of contacting media are obtained. It is shown that, as the distance to the boundary decreases, dipole oscillations acquire resonance nature and become comparable in amplitude with radial oscillations. This effect is of applied value for modern ultrasonic cleaning techniques, because it leads to a considerable increase in bubble-generated microstreaming.