BUBBLE OSCILLATIONS IN THE NEARLY ADIABATIC LIMIT

Miksis and Ting [J. Acoust. Soc. Am. 81, 1331 (1987)] reported examples of a marked increase of the radius of an oscillating gas bubble as predicted by their nearly adiabatic model. They attributed this phenomenon to a process of rectified heat transfer into the bubble. By comparison with a more complete model which contains the nearly adiabatic one as an approximation, it is shown that the real cause of this result is instead the error inherent in the approximation. This error arises primarily from the failure of the approximation to capture the complex behavior of the gas temperature and manifests itself in a spurious growth of the mass of gas contained in the bubble. In addition to being more accurate, the more complete model is also found to be less computationally demanding than the approximate one.