Hostname: page-component-848d4c4894-nr4z6 Total loading time: 0 Render date: 2024-05-01T17:59:04.217Z Has data issue: false hasContentIssue false
  • English
  • Français

Surface breakup and air bubble formation by drop impact in the irregular entrainment region

Published online by Cambridge University Press:  24 September 2007

Y. TOMITA ,
T. SAITO  and
S. GANBARA
Y. TOMITA
Affiliation:
Faculty of Education, Hokkaido University of Education, 1-2 Hachiman-cho, Hakodate, Hokkaido 040-8567, Japantomita@cc.hokkyodai.ac.jp
T. SAITO
Affiliation:
Faculty of Education, Hokkaido University of Education, 1-2 Hachiman-cho, Hakodate, Hokkaido 040-8567, Japantomita@cc.hokkyodai.ac.jp
S. GANBARA
Affiliation:
Faculty of Education, Hokkaido University of Education, 1-2 Hachiman-cho, Hakodate, Hokkaido 040-8567, Japantomita@cc.hokkyodai.ac.jp
Get access Rights & Permissions [Opens in a new window]

Abstract

Drop impact on a water surface can be followed by underwater sounds originating not at the drop impact but when the entrained bubbles oscillate. Although the sound mechanism in the regular bubble entrainment region is well-known, there is less knowledge on the impact phenomena in the irregular bubble entrainment region where various situations can exist, such as many types of bubble formation or even no bubble generation under some conditions. In the present study, the aim is to clarify the dynamics of the water surface after the impact of a primary drop, mainly with diameter 5.2, 5.7 and 6.2mm, each of which is accompanied by a single satellite drop. Special attention was paid to the breakup behaviour of the water surface for Froude number Fr < 300. It was found that three underwater sounds were generated for a single drop impact, besides the sound due to impact itself. The first two were audible to the human ear, but the third one was almost inaudible. The first underwater sound resulted from the oscillation of a single air bubble formed as a result of the satellite drop impact on the bottom of the contracting cavity, and the second sound was due to the oscillation of air bubbles generated during the collapse of the water column. The formation of these air bubbles strongly depends on the Froude number, Weber number (or Bond number) and the aspect ratio of the drop at impact, although involving probability characteristics. Furthermore it is suggested that an air bubble entrapped in a water column plays an important role in increasing the probability of contact between the column surface and the curved free surface. A Japanese Suikinkutsu was introduced as an application of drop-impact-induced sounds. Using an open-type Suikinkutsu an additional experiment was carried out with larger drops with average diameters of 6.2, 7.2 and 7.8, mm.

Type
Papers
Information
Journal of Fluid Mechanics , Volume 588 , 10 October 2007 , pp. 131 - 152
Copyright
Copyright © Cambridge University Press 2007

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Blake, J. R., Tomita, Y. & Tong, R. P. 1998 The art, craft and science of modeling jet impact in a collapsing cavitation bubble. Appl. Sci. Res. 58, 77–90.CrossRefGoogle Scholar
Bourne, N. K., Obara, T. & Field, J. E. 1996 The impact and penetration of a water surface by a liquid jet. Proc. R. Soc. Lond. A 452, 1497–1502.Google Scholar
Chapman, D. S. & Critchlow, P. R. 1967 Formation of vortex rings from falling drops. J. Fluid Mech. 29, 177–185.CrossRefGoogle Scholar
Duineveld, P. C. 1998 Bouncing and coalescence of bubble pairs rising at high Reynolds number in pure water or aqueous surfactant solutions. Appl. Sci. Res. 58, 409–439.CrossRefGoogle Scholar
Franz, G. J. 1959 Splashes as sources of sound in liquids. J. Acoust. Soc. Am. 31, 1080–1096.CrossRefGoogle Scholar
Liow, J.-L. 2001 Splash formation by spherical drops. J. Fluid Mech. 427, 73–105.Google Scholar
Medwin, H., Kurgan, A. & Nystuen, J. A. 1990 Impact and bubble sound from raindrops at normal and oblique incidence. J. Acoust. Soc. Am. 88, 413–418.CrossRefGoogle Scholar
Minnaert, M. 1933 On musical air-bubbles and the sounds of running water. Phi. Mag. 16, 235–248.CrossRefGoogle Scholar
Nystuen, J. A. 1986 Rainfall measurements using underwater ambient noise. J. Acoust. Soc. Am. 79, 972–982.CrossRefGoogle Scholar
Obara, T., Bourne, N. K. & Field, J. E. 1995 Liquid-jet impact on liquid and solid surfaces. Wear 186–187, 388–394.CrossRefGoogle Scholar
Oguz, H. N. & Prosperetti, A. 1990 Bubble entrainment by the impact of drops on liquid surfaces. J. Fluid Mech. 219, 143–179.CrossRefGoogle Scholar
Peregrine, D. H., Shoker, G. & Symon, A. 1990 The bifurcation of liquid bridges. J. Fluid Mech. 212, 25–39.CrossRefGoogle Scholar
Prosperetti, A., Crum, L. A. & Pumphrey, H. C. 1989 The underwater noise of rain. J. Geophys. Res. 94, 3255–3259.CrossRefGoogle Scholar
Prosperetti, A. & Oguz, H. N. 1993 The impact of drops on liquid surfaces and the underwater noise of rain. Annu. Rev. Fluid Mech. 25, 577–602.CrossRefGoogle Scholar
Pumphrey, H. C. & Elmore, P. A. 1990 The entrainment of bubbles by drop impacts. J. Fluid Mech. 220, 539–567.CrossRefGoogle Scholar
Rayleigh, Lord 1894 Theory of Sound, 2nd Edn. Macmillan. (Reprinted 1945, Dover Press.)Google Scholar
Scrimger, J. A. 1985 Underwater noise caused by precipitation. Nature 318, 647–649.CrossRefGoogle Scholar
Shikhmurzaev, Y. D. 2001 Coalescence and breakup: solutions without singularities. IUTAM Symp. on Free Surface Flows (ed. King, A. C. & Shikhmurzaev, Y. D.), pp. 281–288. Kluwer.CrossRefGoogle Scholar
Strasberg, M. 1956 Gas bubbles as sources of sound in liquids. J. Acoust. Soc. Am. 28, 20–26.CrossRefGoogle Scholar
Tatsui, T. 2000 A Story of Suikinkutsu. Kenchiku Shiryo Kenkyuusya Co. Ltd. (in Japanese).Google Scholar
Thoroddsen, S. T., Etoh, T. G. & Takehara, K. 2003 Air entrapment under an impacting drop. J. Fluid Mech. 478, 125–134.CrossRefGoogle Scholar
Tomita, Y. 2004 Suikinkutsu, water-harp-jar. In Encyclopedia of Flow Phenomena (ed. Kambe, T.), pp. 294–295. Maruzen (in Japanese).Google Scholar
Tomita, Y., Kasai, T. & Miura, S. 2003 Irregular bubble entrainment following drop impact on a free surface. Proc. 2003 ASME Cavitation and Multiphase Forum, Honolulu, Hawaii, USA (ed. Brennen, C. E.), FEDSM2003–45015.Google Scholar
Tomita, Y. & Shima, A. 1990 High-speed photographic observations of laser-induced cavitation bubbles in water. Acustica 71, 161–171.Google Scholar
Watanabe, Y. 2004 Analytical study of acoustic mechanism of ‘Suikinkutsu’. Japan. J. Appl. Phys. 43, 9A, 6429–6443.CrossRefGoogle Scholar
Worthington, A. M. 1908 A Study of Splashes. Longmans, Green and Co.Google Scholar
Zhang, X. & Basaran, O. A. 1995 An experimental study of dynamics of drop formation. Phys. Fluids 7, 1184–1203.CrossRefGoogle Scholar