COHEN , Alexandre

I report an experimental study of inertial liquid reorganization into a liquid foam microchannel, also called a Plateau border supported by three soap films. Two perturbations are applied on the Plateau border. Firstly, a liquid drop is injected. Liquid viscosity, drop size and Plateau border size are changed. The liquid redistribution is...

We report a comprehensive study of the flow of liquid triggered by injecting a droplet into a liquid foam microchannel, also called Plateau border. This drop-injected experiment reveals an intricate dynamics for the liquid redistribution, with two contrasting regimes observed, ruled either by inertia or viscosity. We devoted a previous study...

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We subject a single Plateau border channel to a transverse harmonic excitation, in an experiment reminiscent of the historical one by Melde on vibrating strings, to study foam stability and wave properties. At low driving amplitudes, the liquid string exhibits regular oscillations. At large ones, a nonlinear regime appears and the acoustic...

Our experimental configuration deals with an unique Plateau border positioned horizontally. The latter is supplied externally with a droplet of the same liquid, dropped from above. The droplet coalesces with the Plateau border. We study various liquids with different bulk and surface viscosities and surface tension, and Plateau borders of...

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National audience

Our experimental configuration deals with an unique Plateau border positioned horizontally. The latter is supplied externally with a droplet of the same liquid, dropped from above. The droplet coalesces with the Plateau border. We study various liquids with different bulk and surface viscosities and surface tension, and Plateau borders of...

Plateau borders are liquid microchannels located at the contact between three bubbles in liquid foams. They are stable, deformable and can be thought of as quasi-1D model systems to study surface waves in fluid dynamics. We show that the burst of a bubble trapped in a PB produces local constrictions which travel along the liquid channel at...

In flows where the ratio of inertia to gravity varies strongly, large variations in the fluid thickness appear and hydraulic jumps arise, as depicted by Rayleigh. We report a new family of hydraulic jumps, where the capillary effects dominate the gravitational acceleration. The Bond number – which measures the importance of gravitational body...

International audience

We study transient flows of liquid along a single Plateau border (PB). In opposition with a common belief, we show that a fast, inertial regime of flow, very little dependent on the fluid viscosity, can be encountered in the high surface mobility limit. This newly observed regime evolves into the regular viscous regime after a critical distance...

We report a capillary-inertial flow in an unbounded liquid microchannel -a Plateau border in a liquid foam- and discuss its relevance for foam drainage. In contrast to the case of jets of cylindrical geometry, which are susceptible to the Rayleigh-Plateau instability, in this channel any liquid perturbation is dispersed instead of amplified....

International audience

International audience

Our experimental configuration deals with an unique Plateau border positioned horizontally. The latter is supplied externally with a droplet of the same liquid, dropped from above. The droplet coalesces with the Plateau border. We study various liquids with different bulk and surface viscosities and surface tension, and Plateau borders of...