Procédés et mécanique aux petites échelles PROMETHEE
Micro-objets déformables sous forçage hydrodynamique
Microfluidique et Procédés
Organisation des écoulements aux petites échelles
Séparations membranaires
suite...
PROcédés et MEcanique aux peTites écHEllEs
Présentation
L’équipe PROcédés et MEcanique aux petiTes écHEllEs (PROMETHEE) développe des compétences marquées relevant aussi bien de la mécanique des milieux continus que du génie des procédés tout en combinant approche expérimentale et développement de théories et de modèles. L’originalité des études menées se décline selon plusieurs spécificités :
Echelle micro-nano d’observation et d’analyse qui évacue les problématiques liées à la turbulence (régime de Stokes) mais nécessite de considérer des aspects aux frontières de la discipline ;
Rôle prédominant des interfaces : interactions avec les parois solides à l’échelle nano (nano-tubes), interaction fluide-structure avec des membranes fluides ou polymérisée à l’échelle méso ;
Connexion avec les fluides complexes, la matière molle et les systèmes biologiques.
Sur le thème de la micro- et nano-fluidique, les objets d’étude, physico-chimiques (gouttes, capsules,…) et biologiques (vésicules, globules rouges,…), comprennent aussi les procédés intensifiés d’encapsulation et de vectorisation par microréacteur, thèmes en plein essor. L’équipe développe également des outils de caractérisation de l’organisation aux petites échelles comme le développement de simulations numériques pour rendre compte de la ségrégation obtenue au sein de milieux granulaires et la mise au point de méthode chimique de caractérisation des effets de micromélange (mélange à l’échelle moléculaire). A cela s’ajoute une activité de caractérisation et modélisation thermodynamique de milieux complexes.
Les outils numériques développés et mis en œuvre sont variés : intégrale de frontière, éléments finis, immersed boundary method, méthode Lattice Boltzman…
Jinming Lyu, Paul G. Chen, Alexander Farutin, Marc Jaeger, Chaouqi Misbah, et al.. Swirling of vesicles: Shapes and dynamics in Poiseuille flow as a model of RBC microcirculation. Physical Review Fluids, 2023, 8 (2), pp.L021602. ⟨10.1103/PhysRevFluids.8.L021602⟩. ⟨hal-03979358v2⟩ Plus de détails...
We report on a systematic numerical exploration of the vesicle dynamics in a channel, which is a model of red blood cells in microcirculation. We find a spontaneous transition, called swirling, from straight motion with axisymmetric shape to a motion along a helix with a stationary deformed shape that rolls on itself and spins around the flow direction. We also report on a planar oscillatory motion of the mass center, called three-dimensional snaking for which the shape deforms periodically. Both emerge from supercritical pitchfork bifurcation with the same threshold. The universality of these oscillatory dynamics emerges from Hopf bifurcations with two order parameters. These two oscillatory dynamics are put in the context of vesicle shape and dynamics in the parameter space of reduced volume v, capillary number, and confinement. Phase diagrams are established for v = 0.95, v = 0.9, and v = 0.85 showing that oscillatory dynamics appears if the vesicle is sufficiently deflated. Stationary shapes (parachute/bullet/peanut, croissant, and slipper) are fixed points, while swirling and snaking are characterized by two limit cycles.
Jinming Lyu, Paul G. Chen, Alexander Farutin, Marc Jaeger, Chaouqi Misbah, et al.. Swirling of vesicles: Shapes and dynamics in Poiseuille flow as a model of RBC microcirculation. Physical Review Fluids, 2023, 8 (2), pp.L021602. ⟨10.1103/PhysRevFluids.8.L021602⟩. ⟨hal-03979358v2⟩
Jinming Lyu, Paul G. Chen, Alexander Farutin, Marc Jaeger, Chaouqi Misbah, et al.. Swirling of vesicles: Shapes and dynamics in Poiseuille flow as a model of RBC microcirculation. Physical Review Fluids, 2023, 8 (2), pp.L021602. ⟨10.1103/PhysRevFluids.8.L021602⟩. ⟨hal-03979358v1⟩ Plus de détails...
We report on a systematic numerical exploration of the vesicle dynamics in a channel, which is a model of red blood cells in microcirculation. We find a spontaneous transition, called swirling, from straight motion with axisymmetric shape to a motion along a helix with a stationary deformed shape that rolls on itself and spins around the flow direction. We also report on a planar oscillatory motion of the mass center, called three-dimensional snaking for which the shape deforms periodically. Both emerge from supercritical pitchfork bifurcation with the same threshold. The universality of these oscillatory dynamics emerges from Hopf bifurcations with two order parameters. These two oscillatory dynamics are put in the context of vesicle shape and dynamics in the parameter space of reduced volume v, capillary number, and confinement. Phase diagrams are established for v = 0.95, v = 0.9, and v = 0.85 showing that oscillatory dynamics appears if the vesicle is sufficiently deflated. Stationary shapes (parachute/bullet/peanut, croissant, and slipper) are fixed points, while swirling and snaking are characterized by two limit cycles.
Jinming Lyu, Paul G. Chen, Alexander Farutin, Marc Jaeger, Chaouqi Misbah, et al.. Swirling of vesicles: Shapes and dynamics in Poiseuille flow as a model of RBC microcirculation. Physical Review Fluids, 2023, 8 (2), pp.L021602. ⟨10.1103/PhysRevFluids.8.L021602⟩. ⟨hal-03979358v1⟩
Revaz Chachanidze, Kaili Xie, Jinming Lyu, Marc Jaeger, Marc Leonetti. Breakups of Chitosan microcapsules in extensional flow. Journal of Colloid and Interface Science, 2023, 629, pp.445-454. ⟨10.1016/j.jcis.2022.08.169⟩. ⟨hal-03787637⟩ Plus de détails...
The controlled rupture of a core-shell capsule and the timely release of encapsulated materials are essential steps of the efficient design of such carriers. The mechanical and physico-chemical properties of their shells (or membranes) mainly govern the evolution of such systems under stress and notably the link between the dynamics of rupture and the mechanical properties. This issue is addressed considering weakly cohesive shells made by the interfacial complexation of Chitosan and PFacid in a planar extensional flow. Three regimes are observed, thanks to the two observational planes. Whatever the time of reaction in membrane assembly, there is no rupture in deformation as long as the hydrodynamic stress is below a critical value. At low times of complexation (weak shear elastic modulus), the rupture is reminiscent of the breakup of droplets: a dumbell or a waist. Fluorescent labelling of the membrane shows that this process is governed by continuous thinning of the membrane up to the destabilization. It is likely that the membrane shows a transition from a solid to liquid state. At longer times of complexation, the rupture has a feature of solid-like breakup (breakage) with a discontinuity of the membrane. The maximal internal constraint determined numerically marks the initial location of breakup as shown. The pattern becomes more complex as the elongation rate increases with several points of rupture. A phase diagram in the space parameters of the shear elastic modulus and the hydrodynamic stress is established.
Revaz Chachanidze, Kaili Xie, Jinming Lyu, Marc Jaeger, Marc Leonetti. Breakups of Chitosan microcapsules in extensional flow. Journal of Colloid and Interface Science, 2023, 629, pp.445-454. ⟨10.1016/j.jcis.2022.08.169⟩. ⟨hal-03787637⟩
Antoine Galko, Simon Gsell, Umberto d'Ortona, Laurent Morin, Julien Favier. Pulsated Herschel-Bulkley flows in two-dimensional channels: A model for mucus clearance devices. Physical Review Fluids, 2022, 7 (5), pp.053301. ⟨10.1103/PhysRevFluids.7.053301⟩. ⟨hal-03863329⟩ Plus de détails...
Umberto d'Ortona, Nathalie Thomas, Richard M Lueptow. Mechanisms for recirculation cells in granular flows in rotating cylindrical rough tumblers. Physical Review E, 2022. ⟨hal-03431772v2⟩ Plus de détails...
Friction at the endwalls of partially-filled horizontal rotating tumblers induces curvature and axial drift of particle trajectories in the surface flowing layer. Here we describe the results of a detailed discrete element method study of the dry granular flow of monodisperse particles in threedimensional cylindrical tumblers with endwalls and cylindrical wall that can be either smooth or rough. Endwall roughness induces more curved particle trajectories, while a smooth cylindrical wall enhances drift near the endwall. This drift induces recirculation cells near the endwall. The use of mixed roughness (cylindrical wall and endwalls having different roughness) shows the influence of each wall on the drift and curvature of particle trajectories as well as the modification of the free surface topography. The effects act in opposite directions and have variable magnitude along the length of the tumbler such that their sum determines both direction of net drift and the recirculation cells. Near the endwalls, the dominant effect is always the endwall effect, and the axial drift for surface particles is toward the endwalls. For long enough tumblers, a counter-rotating cell occurs adjacent to each of the endwall cells having a surface drift toward the center because the cylindrical wall effect is dominant there. These cells are not dynamically coupled with the two endwall cells. The competition between the drifts induced by the endwalls and the cylindrical wall determines the width and drift amplitude for both types of cells.
Umberto d'Ortona, Nathalie Thomas, Richard M Lueptow. Mechanisms for recirculation cells in granular flows in rotating cylindrical rough tumblers. Physical Review E, 2022. ⟨hal-03431772v2⟩
Mercredi 16 juin 2021
- De la vague déferlante au globule rouge / Soutenance HDR Paul Gang CHEN
Dr. Paul Gang CHEN
Date de soutenance : le mercredi 16 juin à 15h00 (visio - Zoom)
Résumé : au cours de cette soutenance, je présenterai mes différents travaux sur la modélisation et la simulation numérique d’écoulements interfaciaux : de la vague déferlante au globule rouge.
Jury :
M. Daniel Henry, LMFA, École Centrale de Lyon, Rapporteur
M. Grétar Tryggvason, Johns Hopkins University, Rapporteur
M. Stéphane Zaleski, d’Alembert, Sorbonne Université, Rapporteur
M. Richard Saurel, LMA, Aix-Marseille Université
M. Marc Jaeger, M2P2, École Centrale de Marseille, Tuteur
M. Marc Leonetti, LRP, Grenoble, Invité
Mardi 16 Mars
- Preparation of polyurea microcapsules calibrated in size and shell thickness by a microfluidic process for the absorption of ultraviolet / Soutenance de thèse Jiupeng DU
Doctorant : Jiupeng DU
Date de soutenance : le mardi 16 mars à 14h00 en VISIO
Abstract : This thesis aims to exploit the advantages of microfluidics for the production of polyurea microcapsules. Because of its ability to produce drops with a very narrow size distribution, microfluidic emulsification shows great interest as the first step for rapid interfacial polymerisation. Although the literature on the production of drops in microchannels is abundant, commonly used organic solvents are limited to certain toxic hydrocarbon oils or ketones, as these solvents are very hydrophobic and therefore easy to emulsify in water.
The first part of the work concentrates on the feasibility of emulsifying two less hydrophobic green solvents (dibutyl adipate and n-butyl acetate) in water and study the different flow regimes within a hydrophilic flow-focusing microchannel of glass. The results show that the wetting of the walls by dibutyl adipate can be modified by adding a surfactant (Tween 80). However, the formation of the drops being much faster than the transfer of the surfactant to the interface of the drop being formed, concentrations much higher than the critical micellar concentration are necessary to avoid wetting of the walls by the dispersed phase and thus the appearance of disordered flow regimes. The behavior of the n-butyl acetate/water system is similar, but the comparison of the flow maps for the two systems raises the question of the choice of dimensional numbers for representing the transition between the dripping and jetting regimes.
In the second part, the addition of an interfacial polymerization within the emulsion formed by microfluidics is studied in detail. We aim to fabricate polyurea microcapsules calibrated in size and shell thickness containing octyl salicylate (OS). These microcapsules are used to study, for the first time, the influence of the shell thickness of microcapsules on their absorption efficiency against ultraviolet (UV) light. The results show that an increase of the concentration of isocyanate (HDB-LV or hexamethylene diisocyanate biuret) in the organic phase increases the shell thickness of the microcapsules, their encapsulation efficiency and very moderately their average absorbance. The average absorbance of the microcapsules is inversely proportional to the size of the microcapsules (for the same mass of OS). A theoretical model is proposed to estimate the average absorbance as a function of the mass fraction of HDB-LV in the organic phase and of the size of microcapsules. Finally, the concentration of amine (ethylenediamine) has been optimized to ensure the spherical shape of the microcapsules.
Jury:
Marc LEONETTI (CNRS, LRP), Rapporteur
Nathalie LE SAUZE (Univ Toulouse III), Rapportrice
