L. Kondic and Joel I. Gersten,
submitted to Physics of Fluids.
Abstract:
The oscillations of acoustically driven bubbles
in a liquid are explored. In the strong forcing regime, where
bubbles emit sonoluminescent radiation, the velocity of the bubble
wall becomes comparable to the speed of sound in the gas and in
the liquid. The Rayleigh - Plesset equation, which determines the
motion of the bubble wall and several modifications are discussed.
The results for the emitted sonoluminescent radiation turn out to
be very sensitive to the motion of the bubble wall close to the
minimum radius.
The analysis of the sensitivity of a bubble to
surface instabilities is extended to the strong
forcing regime. It is found that the gas and liquid parameters
strongly influence the stability regime of the bubble oscillations.
These include the viscosity of the liquid as well as the surface
tension of the liquid-gas interface. Detailed predictions of the
dependence of the stability on these parameters is given.
A qualitative explanation of some of the characteristics of the
sonoluminescent radiation follows from this analysis.