This Letter reports experiments on the shape and path of air bubbles (diameter range 0.1–0.2 cm) rising in clean water. We find that bubbles in this diameter range have two steady shapes, a sphere and an ellipsoid, depending on the size of the capillary tube from which they detach. The spherical bubbles move significantly slower than the ellipsoidal ones of equivalent volume. Bubbles with diameter less than about 0.15 cm rise rectilinearly. The larger spherical bubbles follow zigzag paths while the larger ellipsoidal bubbles follow spiral paths.
REFERENCES
1.
R. Clift, J. R. Grace, and M. E. Weber, Bubbles, Drops and Particles (Academic, New York, 1978).
2.
J.
Magnaudet
and I.
Eames
, “The motion of high-Reynolds-number bubbles in inhomogeneous flows
,” Annu. Rev. Fluid Mech.
32
, 659
(2000
).3.
G. K. Batchelor, An Introduction to Fluid Dynamics (Cambridge University Press, Cambridge, 1967).
4.
P. C.
Duineveld
, “The rise velocity and shape of bubbles in pure water at high Reynolds number
,” J. Fluid Mech.
292
, 325
(1995
).5.
O.
Miyagi
, “The motion of air bubbles rising in water
,” Technol. Rep. Tohoku Univ.
5
, 135
(1925
).6.
W. L. Haberman and R. K. Morton, “An experimental investigation of the drag and shape of air bubbles rising in various fluids,” David Taylor Model Basin Report 802, 1953.
7.
P. G.
Saffman
, “On the rise of small air bubbles in water
,” J. Fluid Mech.
1
, 249
(1956
).8.
R. A.
Hartunian
and W. R.
Sears
, “On the instability of small gas bubbles moving uniformly in various liquids
,” J. Fluid Mech.
3
, 27
(1957
).9.
N. M.
Aybers
and A.
Tapucu
, “The motion of gas bubbles rising through stagnant liquid
,” Waerme- Stoffuebertrag.
2
, 118
(1969
).10.
C. E.
Willert
and M.
Gharib
, “Three-dimensional particle imaging with a single camera
,” Exp. Fluids
12
, 353
(1992
).11.
The Culligan water purification system consists of one carbon filter, two 0.45 μm filters, one reverse osmosis system, two deionization columns, one ultraviolet water sterilizer and two 0.22 μm filters. The specific resistance of the water is
12.
D.
Ormiéres
and M.
Provansal
, “Transition to turbulence in the wake of a sphere
,” Phys. Rev. Lett.
83
, 80
(1999
).13.
K. Lunde and R. J. Perkins, “Observations on wakes behind spheroidal bubbles and particles,” ASME-FED Summer Meeting, Vancouver, Canada, 1997, paper number FEDSM97-3530.
14.
D. W.
Moore
, “The velocity of rise of distorted gas bubbles in a liquid of small viscosity
,” J. Fluid Mech.
23
, 749
(1965
).15.
R.
Bel Fdhila
and P. C.
Duineveld
, “The effect of surfactant on the rise of a spherical bubble at high Reynolds and Peclet numbers
,” Phys. Fluids
8
, 310
(1996
).
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© 2002 American Institute of Physics.
2002
American Institute of Physics
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