Levitation of Leidenfrost droplets
à 11h en salle C. Brot
When a drop of water is deposited on a hot surface, it levitates and floats on its own vapour as discovered by J.G. Leidenfrost in 1756, this phenomena was rationalised by J. Tyndall in 1890. These Leidenfrost droplets constitute a quasi-frictionless system and may have applications for micro-fluidic devices. In my talk, I will discuss new theoretical and experimental results on Leidenfrost droplet, such as the super-levitation regime [1,2] which takes place for very small droplet radius. In this regime the width of the the vapour film increases when the droplet radius decreases. I will also discuss a new technique for generating Leidenfrost droplet at ambient temperature (20 Celcius) by using a low pressure athmosphere . Finally, I will expose theoretical and experimental results on Leidenfrost drop which are confined in a two-dimensional geometry by mean of a Hele-Shaw cell . These droplets displays a new hydrodynamic instability which leads to large amplitude star-like oscillation mode.
Thomas Frisch (INLN)
Collaboration LPMC : Franck Celestini, Christophe Raufaste et Alexandre Cohen.
 F. Celestini , T. Frisch et Y. Pomeau , "Take-off of Leidenfost droplets"., Phys. Rev Lett 109), 034501, ( (2012).
 Y. Pomeau, M. Le Berre, F. Celestini, T. Frisch, "The Leidenfrost effect : From quasi-spherical droplets to puddles" , C.R. Mecanique 340, p. 867–881 (2012).
 F. Celestini, T. Frisch Y. Pomeau, "Room temperature water Leidenfrost droplets", Soft Matter p. 9535-(2013)
 F. Celestini, T. Frisch, A. Cochen, C. Raufaste, L. Duchemin and Y. Pomeau, "Two dimensional Leidendrofrost drop in a hele shaw cell" , arXiv:1311.4264, to appear , Physics of Fluids (2014).
Fluides & Matériaux Complexes
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