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Tuesday, May 11, 4:00 PM
HARVARD UNIVERSITY Condensed Matter & Applied Physics Seminar (SPECIAL) Division of Engineering and Applied Sciences Maxwell-Dworkin G135
“How to make a VERY thin nozzle: viscous entrainment from a nozzle”
Dr. Wendy Zhang James Franck Institute, University of Chicago
Refreshments will be served following the seminar. Abstract: A small air bubble rising in syrup remains spherical. A larger air bubble deforms, with the trailing end becoming increasingly tapered. For an even larger air bubble, the tapered end "opens", and a thin tendril of air is deposited behind the rising bubble. This is a common example of how viscous fluid entrainment, together with surface tension effects, can create long and thin tendril-like structures, also called liquid spouts. The radius of the spout is often far thinner than imposed length-scales due to nonlinear interaction between the liquid surface and the viscous flow.
Here we use a simple model problem to show how such small length-scales are created. Using arguments based on scale-invariance we also show that, with the proper set-up, the radius of the entrained spout can be made indefinitely thin within the continuum description. Thus it may be possible to create thin wires of microscopic diameter which are macroscopic in length via viscous entrainment.
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