Séminaires

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

Contact :
Laurent Duchemin
Sylvain Patinet
Stéphane Perrard
Etienne Reyssat
responsables-seminaires (arobase) pmmh.espci.fr

PMMH
BARRE CASSAN
BAT A 1ER ETAGE CASE 18
7 QUAI SAINT BERNARD
75005 PARIS
France

Tel : (33) 1 40 79 45 22


Séminaire PMMH - (Benjamin Favier, CNRS, IRPHE, Marseille)

Vendredi 30 septembre de 11h00 à 12h00 - Salle réunion PMMH 1

Interactions between thermal convection and a melting front

A pure and incompressible material is confined between two plates such that it is heated from below and cooled from above. When its melting temperature is comprised between these two imposed temperatures, an interface separating liquid and solid phases appears. Depending on the initial conditions, freezing or melting occurs until the interface eventually converges towards a stationary state. This evolution is studied numerically in a two-dimensional configuration using a phase-field method coupled with the Navier-Stokes equations. Varying the control parameters of the model, we exhibit two types of equilibria : diffusive and convective. In the latter case, Rayleigh-Bénard convection in the liquid phase shapes the solid-liquid front, and a macroscopic topography is observed. A simple way of predicting these equilibrium positions is discussed and then compared with the numerical simulations. In some parameter regimes, we show that multiple equilibria can coexist depending on the initial conditions. We also demonstrate that, in this bi-stable regime, transitioning from the diffusive to the convective equilibrium is inherently a nonlinear mechanism involving finite-amplitude perturbations. If time allows, the particular case of an isothermal solid, for which there is no equilibrium and the solid continuously melts, will be discussed.

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Séminaires  (4)

  • Séminaire PMMH - Virgile Thiévenaz INRAE, PIAF, Clermont-Ferrand
    Vendredi 2 décembre de 11h00 à 12h00 - Salle réunion PMMH 1
    Pinch-off of complex suspensions drops
    Many fluids of our everyday life, from paint to concrete, actually contain solid particles suspended in a liquid. Applications such as inkjet printing require the fragmentation of such suspensions into droplets. Depending on the scale at which one looks at it, a suspension may seem homogeneous or heterogeneous. (...)
  • Séminaire PMMH - Emmanuèle Helfer (CINAM, Marseille)
    Vendredi 9 décembre de 11h00 à 12h00 - Salle réunion PMMH 1
    Biomimicking red blood cell filtration by the spleen
    Blood circulation in our vascular system is a physical tour de force. To distribute oxygen throughout the body, Red blood cells (RBCs) continuously travel through the microcirculation, through thin capillaries that are smaller than their size, and are thus highly deformable. Their deformability is periodically (...)
  • Séminaire PMMH - Valentin LAPLAUD (Ladhyx Polytechnique)
    Vendredi 20 janvier 2023 de 11h00 à 12h00 - Salle réunion PMMH 1
    Growth and mechanics of 'plants on a chip'
    Plant growth is a complex process depending in part on the hydraulics and mechanics of the plant cell, that has been modeled by Lockhart (1965) and Ortega (1985) using a description still used today. To study it experimentally at the cell and organism level we developed a microfluidic system to follow several (...)
  • Séminaire PMMH - Angela Limare (IPGP)
    Vendredi 24 mars 2023 de 11h00 à 12h00 - Salle réunion PMMH 1
    The Earth's mantle in a microwave oven : thermal convection driven by a heterogeneous distribution of heat sources
    Past laboratory experiments of thermo chemical convection have dealt with systems involving fluids with different intrinsic densities and viscosities in a Rayleigh-Bénard setup. Although these experiments have greatly improved our understanding of the Earth's mantle dynamics, they neglect a fundamental component of (...)

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.

Lien vers séminaires café (internes, tous les jeudis)


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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