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...
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…
Carlos Baqueiro, Nelson Ibaseta, Pierrette Guichardon, Laurent Falk. Influence of reagents choice (buffer, acid and inert salt) on triiodide production in the Villermaux–Dushman method applied to a stirred vessel. Chemical Engineering Research and Design, Elsevier, 2018, 136, pp.25-31. 〈10.1016/j.cherd.2018.04.017〉. 〈hal-01771934〉 Plus de détails...
This work studies how deeply the reagents choice influences micromixing characterisation by the Villermaux-Dushman method, when applying it to a 1 litre stainless steel standard vessel with two baffles, stirred by an inclined blade turbine. For the first time, borate and phosphate buffer are compared on their use in the method. It is observed that triiodide production is higher when borate buffer is used. Moreover, perchloric acid leads to higher triiodide production than sulphuric acid, when injecting the same concentration of both acids. Finally, the influence of the ionic strength is also studied, since there has been a great deal of controversy about it over the last years. The results show that the ionic strength affects triiodide production, although relatively slightly. Advice concerning the choice of the reagents is given in conclusion.
Carlos Baqueiro, Nelson Ibaseta, Pierrette Guichardon, Laurent Falk. Influence of reagents choice (buffer, acid and inert salt) on triiodide production in the Villermaux–Dushman method applied to a stirred vessel. Chemical Engineering Research and Design, Elsevier, 2018, 136, pp.25-31. 〈10.1016/j.cherd.2018.04.017〉. 〈hal-01771934〉
Xue Chen, Xun Wang, Paul G. Chen, Qiusheng Liu. Determination of Diffusion Coefficient in Droplet Evaporation Experiment Using Response Surface Method. Microgravity Science and Technology, Springer, 2018, 30, 〈10.1007/s12217-018-9645-2〉. 〈hal-01847206〉 Plus de détails...
Evaporation of a liquid droplet resting on a heated substrate is a complex free-surface advection-diffusion problem, in which the main driving force of the evaporation is the vapor concentration gradient across the droplet surface. Given the uncertainty associated with the diffusion coefficient of the vapor in the atmosphere during space evaporation experiments due to the environmental conditions, a simple and accurate determination of its value is of paramount importance for a better understanding of the evaporation process. Here we present a novel approach combining numerical simulations and experimental results to address this issue. Specifically, we construct a continuous function of output using a Kriging-based response surface method, which allows to use the numerical results as a black-box with a limited number of inputs and outputs. Relevant values of the diffusion coefficient can then be determined by solving an inverse problem which is based on accessible experimental data and the proposed response surface. In addition, on the basis of our numerical simulation results, we revisit a widely used formula for the prediction of the evaporation rate in the literature and propose a refined expression for the droplets evaporating on a heated substrate.
Xue Chen, Xun Wang, Paul G. Chen, Qiusheng Liu. Determination of Diffusion Coefficient in Droplet Evaporation Experiment Using Response Surface Method. Microgravity Science and Technology, Springer, 2018, 30, 〈10.1007/s12217-018-9645-2〉. 〈hal-01847206〉
Jinming Lyu, Paul G. Chen, Gwenn Boedec, Marc Leonetti, Marc Jaeger. Hybrid continuum–coarse-grained modeling of erythrocytes. Comptes Rendus Mécanique, Elsevier Masson, 2018, 346, pp.439-448. 〈10.1016/j.crme.2018.04.015〉. 〈hal-01785429〉 Plus de détails...
The red blood cell (RBC) membrane is a composite structure, consisting of a phospholipid bilayer and an underlying membrane-associated cytoskeleton. Both continuum and particle-based coarse-grained RBC models make use of a set of vertices connected by edges to represent the RBC membrane, which can be seen as a triangular surface mesh for the former and a spring network for the latter. Here, we present a modeling approach combining an existing continuum vesicle model with a coarse-grained model for the cytoskeleton. Compared to other two-component approaches, our method relies on only one mesh, representing the cytoskeleton, whose velocity in the tangential direction of the membrane may be different from that of the lipid bilayer. The finitely extensible nonlinear elastic (FENE) spring force law in combination with a repulsive force defined as a power function (POW), called FENE-POW, is used to describe the elastic properties of the RBC membrane. The mechanical interaction between the lipid bilayer and the cytoskeleton is explicitly computed and incorporated into the vesicle model. Our model includes the fundamental mechanical properties of the RBC membrane, namely fluidity and bending rigidity of the lipid bilayer, and shear elasticity of the cytoskeleton while maintaining surface-area and volume conservation constraint. We present three simulation examples to demonstrate the effectiveness of this hybrid continuum--coarse-grained model for the study of RBCs in fluid flows.
Jinming Lyu, Paul G. Chen, Gwenn Boedec, Marc Leonetti, Marc Jaeger. Hybrid continuum–coarse-grained modeling of erythrocytes. Comptes Rendus Mécanique, Elsevier Masson, 2018, 346, pp.439-448. 〈10.1016/j.crme.2018.04.015〉. 〈hal-01785429〉
Mustapha-Kamel Khelloufi, Etienne Loiseau, Marc Jaeger, Nicolas Molinari, Pascal Chanez, et al.. Spatiotemporal organization of cilia drives multiscale mucus swirls in model human bronchial epithelium. Scientific Reports, Nature Publishing Group, 2018, 8 (1), pp.2447. 〈10.1038/s41598-018-20882-4〉. 〈hal-01713302〉 Plus de détails...
Mucociliary clearance is a biomechanical mechanism of airway protection. It consists of the active transport along the bronchial tree of the mucus, a fluid propelled by the coordinated beating of a myriad of cilia on the epithelial surface of the respiratory tract. The physics of mucus transport is poorly understood because it involves complex phenomena such as long-range hydrodynamic interactions, active collective ciliary motion, and the complex rheology of mucus. We propose a quantitative physical analysis of the ciliary activity and mucus transport on a large panel of human bronchial cultures from control subjects, patients with asthma and chronic obstructive pulmonary disease obtained from endobronchial biopsies. Here we report on the existence of multiple ciliary domains with sizes ranging from the tens of a micron to the centimeter, where ciliary beats present a circular orientational order. These domains are associated with circular mucus flow patterns, whose size scales with the average cilia density. In these domains, we find that the radial increase of the ciliated cell density coupled with the increase in the orientational order of ciliary beats result in a net local force proportional to the mucus velocity. We propose a phenomenological physical model that supports our results.
Mustapha-Kamel Khelloufi, Etienne Loiseau, Marc Jaeger, Nicolas Molinari, Pascal Chanez, et al.. Spatiotemporal organization of cilia drives multiscale mucus swirls in model human bronchial epithelium. Scientific Reports, Nature Publishing Group, 2018, 8 (1), pp.2447. 〈10.1038/s41598-018-20882-4〉. 〈hal-01713302〉
Gustavo Lopes, Nelson Ibaseta, Pierrette Guichardon, Pierre Haldenwang. Effects of solute permeability on permeation and solute rejection in membrane filtration. Chemical Engineering and Technology, Wiley-VCH Verlag, 2018, 41 (4), pp.788-797. 〈10.1002/ceat.201700203〉. 〈hal-01681108〉 Plus de détails...
Membrane solute permeability plays a role in the buildup of concentration polarization in pressure-driven crossflow filtration processes, and thus in the determination of the permeate flux, solute rejection, retentate flux and concentration. We numerically examine reverse-osmosis desalination with membranes of fixed solvent permeability, but of variable selectivity with respect to the solute. The study highlights an intricate coupling between retentate and filtrate properties. In particular, it reveals that, for given values of solute permeability and feed concentration, there is a maximum operating pressure that optimizes solute rejection regardless of the feed salinity. The conditions leading to this and to other peculiar behaviors for permeation fluxes and concentrations are identified.
Gustavo Lopes, Nelson Ibaseta, Pierrette Guichardon, Pierre Haldenwang. Effects of solute permeability on permeation and solute rejection in membrane filtration. Chemical Engineering and Technology, Wiley-VCH Verlag, 2018, 41 (4), pp.788-797. 〈10.1002/ceat.201700203〉. 〈hal-01681108〉
10 Décembre 2014
- "On the Coupling of Membrane Transport to Hydrodynamics and Bulk Mass Transfer in Reverse Osmosis: Numerical Modeling and Experimental Studies" / Soutenance de thèse: Gustavo Henndel Lopes
Doctorant: Gustavo Henndel LOPES
Directrice de thèse: Pierrette GUICHARDON Co-Directeur de thèse: Nelson IBASETA
Date de soutenance: le 10 Décembre 2014 à 10h00, amphithéâtre 1 de l'École Centrale Marseille
Résumé: The prediction of the performance of pressure-driven membrane
separations, deeply affected by concentration polarization, would be an
important advance for process design and optimization. In this context,
the dimensionless coupled Navier-Stokes and solute conservation
equations are solved numerically for a steady laminar cross-flow
filtration. The two-dimensional flat channel consists of permeable walls
subject to solution-diffusion boundary conditions. The permeate flux,
the rejection rate and the retentate's flow rate, concentration and
pressure drop are determined locally. The simulations highlight the
influence of the membrane solute and solvent permeabilities on
concentration polarization and the non-asymptotic dependence of the
rejection rate on the applied pressure. The model is validated for
reverse osmosis and tight-nanofiltration plate-and-frame and
spiral-wound modules by comparison to experimental results from the
literature and from our own pilot desalination tests. Furthermore, a
bench-scale method enabling the determination of solute and solvent
permeabilities from osmotic-diffusive experiments is developed and
applied to reverse osmosis and nanofiltration membranes. The divergence
between the transport mechanisms engendered by pressure and by an
osmotic gradient is evidenced. The numerical model and the experimental
method are new promising tools with immediate applicability in the
membrane field.
Jury: Sébastien DÉON, Maître de conférences, Université de Franche-Comté (Rapporteur)
Pierrette GUICHARDON, Professeur des universités, École Centrale Marseille (Directrice de thèse)
Pierre HALDENWANG, Professeur des universités, Aix Marseille Université (Examinateur)
Nelson IBASETA, Maître de conférences, École Centrale Marseille (Codirecteur de thèse)
Alain LINÉ, Professeur des universités, Inst. Nat. de Sci. Appl. de Toulouse (Rapporteur)
Ana María URTIAGA, Profesora catedrática, Universidad de Cantabria (Examinatrice)
