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Accueil > Équipes > Equipe MEIGE : Modélisation, Expériences et Instrumentation pour la Géophysique et l’Environnement > Diffusion scientifique > Séminaires internes

Dynamics of a Levitating Drop in a Faraday Experiment.

Tobit Caudwell, 19/07/2012

In a recent experiment, a drop has been introduced on top of a liquid layer which
is forced to oscillate. The amplitude of the bath oscillations is close but below Faraday
instability threshold. It has been observed that the drop avoids to collapse into the
bath : it oscillates over the layer on an air film and generates capillary as well as
attenuated Faraday waves in the layer2 . In a certain parameter range, the drop can
even move via a coupling with theses waves.
In this presentation, we will focus on the dynamics of a non moving drop. A
multiphase DNS solver based on a finite elements technique has been built by J.lie
assuming the constraint of axisymmetry. This code is able to obtain numerical data
corresponding to the range of experimental parameters (air viscosity and silicone oil
viscosity, frequencies) and manage to treat the huge scale ratio between drop, Faraday
waves and air film dimensions. The general phase diagram seems to be consistent with
the experimental one and gives some hints about the physics. Different quantities will
be displayed such as time evolution of the dimple that forms under the drop, pressure,
velocity fields and shape of the drop and Faraday waves formation in the bath.
Based on these numerical results, we will propose some low dimensional models
to capture this quite complex interaction.