Behavior of self-propelled acetone droplets in a Leidenfrost state on liquid substrates
It is demonstrated that non-coalescent droplets of acetone can be formed on liquid substrates. The fluid flows around and in an acetone droplet hovering on water are recorded to shed light on the mechanisms which might lead to non-coalescence. For sufficiently low impact velocities, droplets undergo...
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Published in | Physics of fluids (1994) Vol. 29; no. 3 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Melville
American Institute of Physics
01.03.2017
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Subjects | |
Online Access | Get full text |
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Summary: | It is demonstrated that non-coalescent droplets of acetone can be formed on
liquid
substrates. The fluid flows around and in an acetone droplet hovering on water are
recorded to shed light on the mechanisms which might lead to non-coalescence. For
sufficiently low impact velocities, droplets undergo a damped oscillation on the
surface of the
liquid
substrate but at higher velocities clean bounce-off occurs. Comparisons of experimentally
observed static configurations of floating droplets to predictions from a theoretical
model for a small non-wetting rigid sphere resting on a liquid substrate are
made and a tentative strategy for determining the thickness of the vapor layer under a
small droplet on a liquid is proposed. This strategy is based on the notion of effective
surface tension.
The droplets show self-propulsion in straight line trajectories in a manner which can be
ascribed to a Marangoni effect. Surprisingly, self-propelled droplets can become immersed
beneath the undisturbed water surface. This phenomenon is reasoned to be drag-inducing and might
provide a basis for refining observations in previous work. |
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ISSN: | 1070-6631 1089-7666 |
DOI: | 10.1063/1.4977442 |