The acoustic excitation of newly-formed bubbles

• Autorzy: Deane G. , Czerski H. , Stokes D.
• Języki publikacji: EN

Abstrakty

EN

Gas bubbles in water act as oscillators with a natural frequency inversely proportional to their radius and a quality factor determined by thermal, radiation, and viscous losses. Newly-formed gas bubbles are excited into breathing mode oscillations immediately after creation, causing them to radiate a pulse of sound. Although the linear dynamics of spherical gas bubbles are well-understood, the mechanism driving the sound production has not been unambiguously identified. Using bubbles released from a nozzle as a model system, it can be shown that sound production is consistant with the rapid change in volume associated with the collapse of an air neck formed immediately after bubble pinch-off. The model is able to adequately describe the production of sound by bubbles released from a nozzle, and can also explain some of the acoustic properties of bubbles fragmenting in fluid turbulence. Laboratory experiments and model calculations of the mechanism are presented. [Work supported by ONR and NSF].

Słowa kluczowe

EN

gas bubbles; hydroacoustics; natural frequency

• Wydawca: Polskie Towarzystwo Akustyczne. Oddział Gdański
• Czasopismo: Hydroacoustics
• Rocznik: 2008
• Tom: Vol. 11
• Strony: 71--78
• Opis fizyczny: Bibliogr. 7 poz., rys., wykr.

Twórcy

autor

Deane G.

autor

Czerski H.

autor

Stokes D.

• Scripps Institution of Oceanography, UCSD Code 0238, La Jolla, CA 92093-0238, USA,

Bibliografia

• 1. M. Minnaert, On Musical Air Bubbles and the Sounds of Running Water, Philos. Mag., Vol. 16, 235-248 1933.
• 2. T.G. Leighton, The Acoustic Bubble, Academic Press, London 1994.
• 3. H.C. Pumphrey & J.E. Ffowcs Williams, Bubbles as Sources of Ambient Noise, IEEE J. Ocean Eng., Vol. 15, 268-274, 1990.
• 4. M.S. Longuet-Higgins, Nonlinear damping of bubble oscillations by resonant interaction, J. Acoust. Soc. Am., Vol. 91, 1414-1422, 1992.
• 5. G.B. Deane & M.D. Stokes, Scale dependence of bubble creation mechanisms in breaking waves, Nature, Vol. 418, 839-844, 2002.
• 6. A. Prosperetti, Thermal effects and damping mechanisms in the forced radial oscillations of gas bubbles in liquids, J. Acoust. Soc. Am., Vol. 61, 17-27, 1977.
• 7. G.B. Deane & M.D. Stokes, The acoustic signature of bubbles fragmenting in sheared flow, JASA-EL, Vol. 120, EL84-EL89, 2006.