RAUFASTE , Christophe

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We experimentally investigate the behavior of ferrofluid Leidenfrost droplets subject to a static magnetic field gradient. The droplets are deposited on a hot substrate and trapped over the vertical axis of a permanent magnet placed at a distance d above the substrate. Several effects are observed. Firstly, the droplet evaporation rate is...

We investigate the interaction that occurs between a light solid cube falling under gravity and a horizontal soap film that is pinned to a circular ring. We observe in both experiments and quasi-static simulations that the final orientation of a cube that becomes entrapped by a soap film is strongly dependent on the Bond number. A cube is...

We investigate the effects of the contact angle $\theta_w$, and the angle of inclination $\theta_i$ on the interaction between an infinite cylinder and a free fluid-fluid interface governed only by its surface tension. We describe a numerical method to calculate the deformation of the interface, and use it to validate a theory for the force on...

Aqueous foams are suspensions of bubbles inside aqueous phases. Their multiphasic composition leads to a complex rheological behavior that is useful in numerous applica-tions, from oil recovery to food/cosmetic processing. Their structure is very similar to the one of emulsions, so that both materials share common mechanical properties. In...

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We investigate the impact of composite objects. They consist of a soft layer on top of a rigid part with a hemispherical impacting end. The coefficient of restitution (e) of such objects is studied systematically as a function of the mass ratio and of the nature of the materials. For rather elastic materials, the coefficient of restitution is a...

Abstract The topic of collisions is introduced in university education to address the laws of conservation of momentum and energy. In particular, students are asked to classify collisions as either elastic or inelastic. They are often left with the idea that 'macroscopic energy' has been transformed into 'microscopic energy' in the case of an...

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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...

We experimentally investigate the reactivity of Leidenfrost droplets with their supporting substrates. Several organic liquids are put into contact with a copper substrate heated above their Leidenfrost temperature. As the liquid evaporates, the gaseous flow cleans the superficial copper oxide formed at the substrate surface and the reaction...