The acoustic characteristics of bubbly liquids near the individual bubble resonance frequency

Abstract

In biomedical, naval and oceanographic arenas, the acoustic characteristics of bubbly liquids have simultaneously confounded and been exploited by acoustic tools used in the respective fields. The work of Carstensen and Foldy [J. Acoust. Soc. Am. 19, 481-501 (1947)] served as a cornerstone of the post-World War II understanding of this system, but at high bubble concentrations near the individual bubble resonance frequency (IBRF), the quantitative prediction and measurement of bubbly liquid sound speed and attenuation remains an open topic. In 1989, Commander and Prosperetti [J. Acoust. Soc. Am. 85 732-746 (1989)] advanced the field with a rigorous model valid at the IBRF but it was limited to low void fractions. The data available in 1989 did not corroborate their model at IBRF, but at the time, it was unclear whether this was due to model or experimental deficiencies. This paper reviews an impedance tube measurement [J. Acoust. Soc. Am. 117, 1895-1910 (2005)] that did validate the model for bubble volume fractions up to about 10-4, and also reviews more recent work associated with an industrial underwater noise mitigation system, that validates their model up to void fractions exceeding 10-2, significantly higher than expected.