Effects of super-hydrophobic coatings on free falling spheres

M. Castagna, M. P. Eisfelder, H. Taylor, N. Mazellier, A. Kourta, J. Soria

Research output: Chapter in Book/Report/Conference proceedingConference PaperOther

Abstract

The present work deals with a joint experimental investigation of free falling super-hydrophobic spheres in pure water at rest. The results derive from a collaboration between the University of Orléans (France) and the Monash University (Australia). The super-hydrophobic coatings have the ability, once immersed into water, to reduce the contact area between the liquid and the solid surface by entrapping an air layer in the surface roughness. We thus investigate a possible effect of this feature on the hydrodynamic drag of spheres, focusing on the terminal velocity region. Surprisingly, the hydrodynamic performance of super-hydrophobic coatings depends on the analysed Reynolds number regime. The drag increase evidenced for the small diameter spheres tends progressively to turn into a drag attenuation for the largest diameters spheres. A possible connection between the hydrodynamic performance and the deformation of the air layer encapsulating the coated spheres is proposed.

Original languageEnglish
Title of host publicationProceedings of the 21st Australasian Fluid Mechanics Conference
EditorsTimothy C.W. Lau, Richard M. Kelso
PublisherAustralasian Fluid Mechanics Society
Number of pages4
ISBN (Electronic)9780646597843
Publication statusPublished - 2018
EventAustralasian Fluid Mechanics Conference 2018 - Adelaide Convention Centre, Adelaide, Australia
Duration: 10 Dec 201813 Dec 2018
Conference number: 21st
https://aomevents.eventsair.com/QuickEventWebsitePortal/21st-australasian-fluid-mechanics-conference/afmc2018

Conference

ConferenceAustralasian Fluid Mechanics Conference 2018
Abbreviated titleAFMC 2018
CountryAustralia
CityAdelaide
Period10/12/1813/12/18
Internet address

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