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Evidence of slippage breakdown for a superhydrophobic microchannel
journal contribution
posted on 2017-06-22, 11:03 authored by Guido Bolognesi, C. Cottin-Bizonne, C. Pirat© 2014 AIP Publishing LLC.A full characterization of the water flow past a silicon superhydrophobic surface with longitudinal micro-grooves enclosed in a microfluidic device is presented. Fluorescence microscopy images of the flow seeded with fluorescent passive tracers were digitally processed to measure both the velocity field and the position and shape of the liquid-air interfaces at the superhydrophobic surface. The simultaneous access to the meniscus and velocity profiles allows us to put under a strict test the no-shear boundary condition at the liquid-air interface. Surprisingly, our measurements show that air pockets in the surface cavities can sustain non-zero interfacial shear stresses, thereby hampering the friction reduction capabilities of the surface. The effects of the meniscus position and shape as well as of the liquid-air interfacial friction on the surface performances are separately assessed and quantified.
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Chemical Engineering
Published in
Physics of FluidsVolume
26Issue
8Citation
BOLOGNESI, G., COTTIN-BIZONNE, C. and PIRAT, C., 2014. Evidence of slippage breakdown for a superhydrophobic microchannel. Physics of Fluids, 26: 082004.Publisher
© American Insitute of Physics (AIP)Version
- VoR (Version of Record)
Publication date
2014-08-13Notes
This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. The following article appeared in BOLOGNESI, G., COTTIN-BIZONNE, C. and PIRAT, C., 2014. Evidence of slippage breakdown for a superhydrophobic microchannel. Physics of Fluids, 26: 082004. and may be found at http://dx.doi.org/10.1063/1.4892082ISSN
1070-6631eISSN
1089-7666Publisher version
Language
- en