MICHAEL MANGA: Recent Refereed Publications
Manga, M. and H.A. Stone (1995) Collective hydrodynamics of deformable
drops and bubbles
in dilute suspensions at low Reynolds numbers,
Journal of Fluid Mechanics, vol. 300, 231-263.
Deformation due to hydrodynamic interactions between
two deformable buoyant drops may result in the
alignment and coalescence of horizontally offset drops.
Three-dimensional boundary integral calculations are presented for
systems containing two drops, three drops or four drops and it is argued that
the interactions which occur between three drops or four drops
may be characterized qualitatively by the two drop
In a dilute monodisperse suspension,
the rate of coalescence of deformable drops is calculated using
analytical results, and is found to
be proportional to the Bond number.
The rate of coalescence in a dilute polydisperse
of bubbles in corn syrup is determined by performing
a large number of laboratory experiments
for Bond numbers based on the larger bubble radius
15 < B < 120.
The rate of coalescence
is enhanced (by a factor of 10 for B=10)
owing to the effects of deformation compared to
the predictions of
models which include hydrodynamic interactions
and van der Waals forces
among spherical bubbles.
The rate of coalescence is greater than the rate predicted by the
Smoluchowski model which ignores all hydrodynamic interactions.
The experimental results are used to calculate the evolution of the
distribution in suspensions using a standard
one-dimensional population dynamics model;
deformation affects the size-distribution in suspensions,
resulting in a wider range of bubble sizes.
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