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Atomisation d'un jet liquide par un courant gazeux

Abstract : The atomisation of a liquid jet into a spray of droplets was studied, in an experimental set-up where its surface is submitted to a fast coaxial gaseous stream. Jet visualisation reveals that drop formation is preceeded by a transient stage of liquid ligaments stretched from the liquid jet. The explanation is that its surface is unstable within the shear flow of gaz. The smooth exiting surface is seeded by growing axisymetric disturbances whose wavelength is fixed by the shear layer thickness. Transverses modulations are superimposed on the crest of these ondulations, their spacing is derived from a balance between capillary forces and gaz inertia. The modulations grow and are stretched by air flow to the stage of ligaments. The future of this ligament is doomed with modulation spacing. The ligament break-up takes place when capillary forces seize and fragment them. This is the birth of droplets whose mean diameter is proportionnal to the modumation spacing. Their large distribution is well accounted for by a model including sizes interaction during break-up. The spray that results from break-ups also displays a large range of diameters. The drop size distribution is exponentially decaying towards increasing sizes. The mean diameter in the spray is proportional to transverse spacing and inversely proportional to the gaz flow velocity.
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https://tel.archives-ouvertes.fr/tel-00003054
Contributor : Marmottant Philippe <>
Submitted on : Thursday, June 26, 2003 - 4:11:32 PM
Last modification on : Tuesday, March 30, 2021 - 3:12:39 AM
Long-term archiving on: : Tuesday, September 11, 2012 - 9:00:29 PM

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  • HAL Id : tel-00003054, version 1

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Philippe Marmottant. Atomisation d'un jet liquide par un courant gazeux. Dynamique des Fluides [physics.flu-dyn]. Institut National Polytechnique de Grenoble - INPG, 2001. Français. ⟨tel-00003054⟩

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