SEMINAIRE MERCREDI 11 OCTOBRE 2006 14 heures Salle Séminaire 5 Centre de Physique Théorique Marseille-Luminy Xavier Leoncini CPT Title: Particles dynamics in regular flows Abstract: In this talk we will consider the dynamics of passive tracers in a system of three point vortices, in an array of vortices as well as three-dimensional steady flows. These dynamics are all particular examples of chaotic advection. This phenomenon has fundamental implication in various physical systems. On large scales one may for instance think as plasma physics (confinement), geophysical flows (pollution). But also on a much smaller scale for micro-fluidic devices, for which chaotic advection seems to be the best candidate in order to trigger mixing wihtout breaking anything. For the point vortex flow some motivation of the choice of the flow and the dynamics of vortices will be given.