An explanation is provided for the influence of relatively small changes in liquid temperature on the hot spot within a sonoluminescence bubble. This influence derives from a change in the (stable) equilibrium mass of the bubble due to a variation of the gas solubility in the liquid with temperature. If the acoustic drive amplitude is held constant, a change in the liquid temperature has a large or small effect depending on the variability of the solubility with temperature. For a gas like xenon, which has rapidly decreasing solubility in water with increasing temperature, a decrease in water temperature shifts the stable mass exchange equilibrium to a smaller bubble size. This increases the ratio of maximum to minimum bubble radius over an acoustic cycle, resulting in a much higher hot spot temperature. In contrast helium has very little variation of solubility with temperature near room temperature; therefore the hot spot temperature is relatively insensitive to variations in the liquid temperature outside a helium bubble.
ASJC Scopus subject areas
- Arts and Humanities (miscellaneous)
- Acoustics and Ultrasonics