Séminaires PMMH

Séminaire PMMH - Site Jussieu

Séminaires café

Contact :
Benoit Semin
Sylvain Patinet
Etienne Reyssat
responsables-seminaires (arobase) pmmh.espci.fr

75005 PARIS

Tel : (33) 1 40 79 45 22

Comment venir ?

7 quai Saint Bernard, 75005 PARIS

Le séminaire hebdomadaire du laboratoire PMMH a lieu tous les vendredis à 11h, au premier étage Barre Cassan, campus Jussieu.

Séminaire PMMH- Elisabeth Guazzelli (MSC)

Vendredi 7 février 11:00-12:00 - Salle réunion PMMH 1

Particle motion in vortical flows

In many natural phenomena or industrial applications, heavy particles are transported in complex flows. The flow structures may happen to promote the stirring and dispersion of the particles. But the opposite can also take place and the flow configuration may contribute to the focussing and accumulation of particles within specific regions of the flow. A typical example in the natural environment is the observed patchiness of plankton concentration caused by wind-induced Langmuir cells occurring at the surface of lakes and oceans. The objective of this work is to examine the interactions of particles with local spatial structures of the flow, i.e. large vortices. We first consider the settling of particles under the action of gravity in a cellular flow field which is a simple model flow capturing key features of vortical effects on the particles. The experiment uses electroconvection to generate a two-dimensional array of controlled vortices. Experimental observations are compared to the predictions of point-particle simulations. We examine the motion of single particles (spheres and also anisotropic particles such as fibers) but also of clouds of particles to address the interplay between the multibody particle interactions and the interaction between the particles and the spatial structures of the flow. We finally consider the interactions of particles with wakes and recirculating flows around obstacles in a channel and are particularly interested in the understanding of the particle exchange between the recirculating flow regions and the free stream.

This work has been undertaken in Laboratoire IUSTI, Aix Marseille Université, CNRS, in collaboration with O. Ait Oucheggou, L. Bergougnoux, G. Bouchet, D. Lopez, B. Marchetti. The work on `Particle-laden flow around an obstacle in a pipe' is in collaboration with V. Pointeau and G. Ricciardi, CEA Cadarache.

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Séminaires  (3)

  • Séminaire PMMH- Kristina Davitt (ENS)
    Vendredi 24 janvier 11:00-12:00 - Salle réunion PMMH 1
    Wetting hysteresis and dynamics : interpreting dissipation mechanisms at the contact line
    A liquid moving over a solid substrate is an everyday occurrence, and the hysteresis and dynamics of the three-phase contact line have been measured in innumerable experiments over the years. In addition, the ingredients needed to describe the phenomenon are known : in the most basic picture, there is viscous (...)
  • Séminaire PMMH- Dwight Barkley (University of Warwick)
    Vendredi 31 janvier 11:00-12:00 - Salle réunion PMMH 1
    A fluid mechanic's analysis of the tea-cup singularity
    In 1926 Einstein published a short paper explaining the meandering of rivers. He famously began the paper by discussing the secondary flow generated in a stirred tea cup — the flow now widely known to be responsible for the collection of tea leaves at the center of a stirred cup of tea. In 2014, Luo and Hou (...)
  • Séminaire PMMH - Sergei Nechaev (Center Poncelet, CNRS UMI 2615)
    Vendredi 3 avril 11:00-12:00 - Salle réunion PMMH 1
    Anomalous statistics of extreme random processes
    I am going to discuss two problems of extreme statistics in which unusual (but related to each other) features arise : i) statistics of two-dimensional "stretched" random walks over a semicircle with Kardar-Parisi-Zhang (KPZ) scaling, ii) spectral properties of symmetric three-diagonal random matrices (operators) (...)

Instructions générales pour les conférenciers

Le public du séminaire est très hétérogène (rien qu’au PMMH nous travaillons sur des thématiques très diverses, mécanique des fluides, des milieux granulaires, des solides, physique statistique, physique du mouillage, micro-fluidique, biophysique,...) l’objectif est donc de ne pas faire un séminaire trop spécialiste : au moins la première moitié du séminaire à un niveau accessible pour celui qui ne connaît rien sur le sujet.

Le séminaire a lieu à 11h. rendez-vous 15 minutes avant pour installer et tester la projection.

Le séminaire dure environ 45 minutes pour laisser un peu de temps pour discuter à la fin.

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Informations Pratiques

Laboratoire : 01 40 79 45 22
Directeur : Damien Vandembroucq
Codirecteur : Philippe Petitjeans
Administratrice : Frédérique Auger (01 40 79 45 22)
Gestionnaire : Claudette Barez (01 40 79 58 53)
Courriel : dir (arobase) pmmh.espci.fr

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