Significant and stable drag reduction with air rings confined by alternated superhydrophobic and hydrophilic strips
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Accepted version
Supporting information
Author(s)
Type
Journal Article
Abstract
Superhydrophobic surfaces have the potential to reduce the viscous drag of liquids by significantly decreasing friction at a solid-liquid interface due to the formation of air layers between solid walls and interacting liquids. However, the trapped air usually becomes unstable due to the finite nature of the domain over which it forms. We demonstrate for the first time that a large surface energy barrier can be formed to strongly pin the three-phase contact line of air/water/solid by covering the inner rotor of a Taylor-Couette flow apparatus with alternating superhydrophobic and hydrophilic circumferential strips. This prevents the disruption of the air layer, which forms stable and continuous air rings. The drag reduction measured at the inner rotor could be as much as 77.2%. Moreover, the air layers not only significantly reduce the strength of Taylor vortexes but also influence the number and position of the Taylor vortex pairs. This has strong implications in terms of energy efficiency maximization for marine applications and reduction of drag losses in, for example, fluid transport in pipelines and carriers.
Date Issued
2017-09-01
Date Acceptance
2017-08-04
Citation
Science Advances, 2017, 3 (9), pp.1-10
ISSN
2375-2548
Publisher
American Association for the Advancement of Science: Science Advances
Start Page
1
End Page
10
Journal / Book Title
Science Advances
Volume
3
Issue
9
Copyright Statement
Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Identifier
https://advances.sciencemag.org/content/3/9/e1603288/
Grant Number
EP/N025954/1
Subjects
Science & Technology
Multidisciplinary Sciences
Science & Technology - Other Topics
TAYLOR-COUETTE FLOW
SKIN-FRICTION DRAG
ULTRAHYDROPHOBIC SURFACES
REYNOLDS-NUMBERS
PARTIAL CAVITY
BUBBLE
LAYER
CAVITATION
TRANSITION
CYLINDERS
Publication Status
Published
Article Number
e1603288
Date Publish Online
2017-09-01