Published In
Physics of Fluids
Document Type
Article
Publication Date
10-2016
Subjects
Capillarity -- Research, Microfluidics, Fluid dynamics
Abstract
Large droplets and puddles jump spontaneously from sufficiently hydrophobicsurfaces during routine drop tower tests. The simple low-cost passive mechanism can in turn be used as an experimental device to investigate dynamic droplet phenomena for drops up to 104 times larger than their normal terrestrial counterparts. We provide and/or confirm quick and qualitative design guides for such “drop shooters” as employed in drop tower tests including relationships to predict droplet ejection durations and velocities as functions of drop volume, surface texture, surface contour, wettability pattern, and fluid properties including contact angle. The latter is determined via profile image comparisons with numerical equilibrium interface computations. Water drop volumes of 0.04–400 ml at ejection speeds of −0.007–0.12 m/s are demonstrated herein. A sample application of the drop jump method is made to the classic problem of low-gravity phase change heat transfer for large impinging drops. Many other candidate problems might be identified by the reader.
DOI
10.1063/1.4963686
Persistent Identifier
http://archives.pdx.edu/ds/psu/19397
Citation Details
Attari, B., Weislogel, M., Wollman, A., Chen, Y., & Snyder, T. (2016). Puddle jumping: Spontaneous ejection of large liquid droplets from hydrophobic surfaces during drop tower tests. Physics of Fluids, 28(10), 102104.
Description
This is the publisher's final pdf. Copyright (2016) AIP. Version of record can be found at https://dx.doi.org/10.1063/1.4963686