Hostname: page-component-848d4c4894-wg55d Total loading time: 0 Render date: 2024-05-27T14:02:05.706Z Has data issue: false hasContentIssue false

The stability of a large gas bubble rising through liquid

Published online by Cambridge University Press:  21 April 2006

G. K. Batchelor
Affiliation:
Department of Applied Mathematics & Theoretical Physics, University of Cambridge, Silver Street, Cambridge CB3 9EW, UK

Abstract

The upper surface of a large gas bubble rising steadily through liquid under gravity is a statically unstable interface, and if the liquid were stationary small sinusoidal disturbances to the interface with wavelength exceeding the critical value Λc determined by surface tension would grow exponentially. The existence of the deforming motion of the liquid adjoining the interface of a steadily rising bubble changes the nature of the problem of stability. It is shown that a small sinusoidal disturbance of the part of the interface that is approximately plane and horizontal remains sinusoidal, although with exponentially increasing wavelength. The amplitude of such a disturbance increases, from the instant at which Λ = Λc until Λ becomes comparable with the radius of curvature of the interface (R), and the largest amplification occurs for a disturbance whose initial wavelength is approximately equal to Λc. With a plausible guess at the disturbance amplitude and wavelength at which bubble break-up due to nonlinear effects is inevitable, it is possible to obtain an approximate numerical relation between the initial magnitude of the disturbance and the maximum value of R for which a bubble remains intact. This relation applies both to a spherical-cap bubble in a large tank and a bubble rising in a vertical tube in which the liquid far ahead of the bubble is stationary. The few published observations of the maximum size of spherical-cap bubbles are not incompatible with the theory, but lack of information about the magnitude of the ambient disturbances in the liquid precludes any close comparison.

Type
Research Article
Copyright
© 1987 Cambridge University Press

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.)

Footnotes

With an appendix by Herbert E. Huppert.

References

Abramowitz, M. & Stegun, I. A. 1965 Handbook of Mathematical Functions. U.S. Government Printing Office.
Allred, J. & Blount, G. 1953 Experimental studies of Taylor instability. Los Alamos Scientific Laboratory Rep. LA 1600.
Bellman, R. & Pennington, R. H. 1954 Effects of surface tension and viscosity on Taylor instability. Q. Appl. Maths 12, 151162.Google Scholar
Clift, R. & Grace, J. R. 1972 The mechanism of bubble break-up in fluidised beds. Chem. Engng Sci. 27, 23092310.Google Scholar
Clift, R., Grace, J. R. & Weber, M. E. 1978 Bubbles, Drops and Particles. Academic.
Collins, R. 1965 Structure and behaviour of wakes behind two-dimensional air bubbles in water. Chem. Engng Sci. 20, 851853.Google Scholar
Dagan, G. 1975 Taylor instability of a non-uniform free-surface flow. J. Fluid Mech. 67, 113123.Google Scholar
Davenport, W. G., Bradshaw, A. V. & Richardson, F. D. 1967 Behaviour of spherical-cap bubbles in liquid metals. J. Iron Steel Inst. 205, 10341042.Google Scholar
Davies, R. M. & Taylor, G. I. 1950 The mechanics of large bubbles rising through extended liquids and through liquids in tubes. Proc. R. Soc. Lond. A 200, 375390; and Scientific Papers of G. I. Taylor, vol. 3, p. 479–492. Cambridge University Press.Google Scholar
Erdelyi, A. 1956 Asymptotic Expansions. Dover.
Frankel, I. & Weihs, D. 1985 Stability of a capillary jet with linearly increasing axial velocity (with application to shaped charges). J. Fluid Mech. 155, 289307.Google Scholar
Grace, J. R., Wairegi, T. & Brophy, J. 1978 Break-up of drops and bubbles in stagnant media. Can. J. Chem. Engng 65, 38.Google Scholar
Harper, J. F. 1972 The motion of bubbles and drops through liquids. Adv. Appl. Mech. 12, 59129.Google Scholar
Moore, D. W. & Griffith-Jones, R. 1974 The stability of an expanding circular vortex sheet. Mathematika 21, 128.Google Scholar
Pelce, P. 1986 Dynamique des front courbes. Doctoral thesis submitted to The University of Provence.
Taylor, G. I. & Davies, R. M. 1944 The rate of rise of large volumes of gas in water. Reproduced in Underwater Explosions Research, vol. 2. Office of Naval Research, Washington, 1950.
Temperley, H. N. V. & Chambers, L. G. 1945 The rate of rise of large volumes of gas in water. Reproduced in Underwater Explosions Research, vol. 2. Office of Naval Research, Washington, 1950.
Tomotika, S. 1936 Breaking up of a drop of viscous liquid immersed in another viscous fluid which is extending at a uniform rate. Proc. R. Soc. Lond. A 153, 302318.Google Scholar
Wegener, P. P. & Parlange, J.-Y. 1973 Spherical-cap bubbles. Ann. Rev. Fluid Mech. 5, 79100.Google Scholar