Hydrodynamics of active and passive particles in Stokes regime : bacteria at interfaces and sedimentation through a cellular flow
Lundi 3 novembre 2014 14:00
- Duree : 1 heure
Lieu : Conference room - LIPhy - Bât E - 140 Avenue de la Physique - St Martin d’Hères. Accès par interphone, appeler le secrétariat
Orateur : Diego LOPEZ (Aix-Marseille Universite)
In this talk I will discuss two aspects of small particles hydrodynamic interactions in Stokes regime,
first in the case of bacteria swimming close to complex interfaces, and then considering the problem of
particle advection and sedimentation in a cellular flow. The locomotion of swimming microorganisms
such as bacteria can be signicantly altered by nearby boundaries. In particular, microorganisms using
helical propulsion tend to swim in circles. Using an analytical model, we show how dierent complex
interfaces affect a nearby bacterium and modify its swimming properties.
In the presence of an external ow, the sedimentation of small passive particles can be signicantly
modied, in particular in vortical or turbulent flows. In this work, we study the competition of the
different terms involved in particle advection using a model experiment, where isolated particles can be
tracked in a controlled quasi-2D cellular flow. We investigate the role of inertia on the settling rate and
trajectories, for small spherical particles and slender rods.
Contact : philippe.peyla@ujf-grenoble.fr
Discipline évènement : (Biologie / Chimie)
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Discipline évènement : (Physique)
Entité organisatrice : (LIPhy)
Nature évènement : (Séminaire)
Evènement répétitif : (Séminaire Mat. Molle/grise)
Site de l'évènement : Domaine Universitaire de St Martin d’Hères
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