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The response of microscopic bubbles to sudden changes in the ambient pressure

Published online by Cambridge University Press:  26 April 2006

Bing Ran  and
Joseph Katz
Bing Ran
Affiliation:
Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA
Joseph Katz
Affiliation:
Department of Mechanical Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA
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Abstract

This paper focuses on the résponse of bubbles to sudden changes in the ambient pressure. Trains of bubbles with radii varying between 45 and 200 μm were exposed to various pressure steps, and their response was monitored by pulsed laser holography. The experiments were performed in a specially constructed chamber, allowing generation of pressure steps ranging from 0.1 to 20 times the initial value. Air, CO2, helium and hydrogen bubbles were selected, providing a range of mass, thermal diffusivities, solubilities in water and isentropic constants. The changes in the bubbles’ diameters were determined by reconstructing the holograms, magnifying the images and measuring the sizes of individual bubbles. Most of the experiments were performed with pressure changes at the rate of 20 KPa/ms, and most data were recorded in less than 20 ms. The results confirm that, within the present range of test conditions, the bubbles can respond instantaneously to changes in the ambient pressure. The experiments also demonstrate that the response of the bubbles at the present timescales can be assumed to be isothermal (polytropic constant of 1.0), irrespective of the bubble content or size. Repeated measurements with different pressure waveforms, but with the same final pressure resulted in identical results, demonstrating that bubbles can be used as pressure sensors. Variations in timescales up to a few hundred milliseconds still resulted in the same response, confirming the isothermal assumption. The dissolved gas content had a noticeable effect on the behaviour of the CO2 bubbles, the most soluble of the gases tested, and had no detectable effect on the behaviour of air bubbles. The paper also includes a detailed error evaluation of the present experiments and an estimate of the expected error when the bubbles are utilized as pressure sensors.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 224 , March 1991 , pp. 91 - 115
Copyright
© 1991 Cambridge University Press

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References

Arndt, R. E. A.: 1981 Cavitation in fluid machinery and hydraulic structures. Ann. Rev. Fluid Mech. 13, 273–328.Google Scholar
Arndt, R. E. A. & George, W. K. 1978 Pressure fields and cavitation in turbulent shear flows. In 12th Symp. on Naval Hydrodynamics, Washington DC, pp. 327–339.Google Scholar
Collier, R. J., Burkhardt, C. B. & Lin, L. H., 1970 Optical Holography. Academic.
Crum, L. A.: 1983 The polytropic exponent of gas contained within air bubbles pulsating in a liquid. J. Acoust. Soc. Am. 73, 116–120.Google Scholar
Fuchs, H. V.: 1972 Measurements of pressure fluctuations within subsonic turbulent jets. J. Sound Vib. 22, 361–378.Google Scholar
Green, S. I.: 1988 Tip vortices — single phase and cavitating flow phenomena. Ph.D. thesis, California Institute of Technology; Rep. No. Eng. 183–17.
Hsieh, D. Y. & Plesset, M. S., 1961 Theory of rectified diffusion of mass into gas bubbles. J. Acoust. Soc. Am. 33, 206–215, February.Google Scholar
Hussain, A. K. M. F.: 1986 Coherent structures and turbulence. J. Fluid Much. 173, 303–356.Google Scholar
Keller, J. B. & Miksis, M., 1980 Bubble oscillations of large amplitude. J. Acoust. Soc. Am. 68, 628–633.Google Scholar
O'Hern, T. J.: 1987 Cavitation inception scale effects: I. Nuclei distributions in natural waters; II. Cavitation inception in turbulent shear flow. Ph.D. thesis, California Institute of Technology; Rep. No. 183–15.
Ooi, K. K. & Acosta, A. J., 1983 The utilization of specially tailored air bubbles as static pressure sensors in a jet. Trans. ASME I: J. Fluids Engng 106, No. 4, pp. 459–465.Google Scholar
Plesset, M. S. & Prosperetti, A. P., 1977 Bubble dynamics and cavitation. Ann. Rev. Fluid Mech. 9, 145–185.Google Scholar
Prosperetti, A. P.: 1977 Thermal effects and damping mechanisms in the forced radial oscillations of gas bubbles in liquids. J. Acoust. Soc. Am. 61, 17–27.Google Scholar
Prosperetti, A. P.: 1984 Bubble phenomena in sound fields: Part two. Ultrasonics 22, 69–77.Google Scholar
Prosperetti, A. P., Crum, L. A. & Commander, K. W., 1988 Nonlinear bubble dynamics. J. Acoust. Soc. Am. 83, 502–514.Google Scholar