Procédés et mécanique aux petites échelles PROMETHEE
Micro-objets biomimétiques & encapsulation
Modélisation des surfaces et des interfaces
Micro-mélange
suite...
Présentation
L'équipe PROMETHEE (Procédés et mécanique aux petites échelles) s'intéresse à des thématiques scientifiques aussi variées que pointues:
étude microfluidique de fluides complexes et bio-fluides,
procédés et systèmes micro-structurés,
modélisation mathématique, physique et numérique des interfaces et des interactions fluide-structure.
La complexité introduite par ces phénomènes nécessite le développement de méthodologies originales développées dans le groupe. Ces développements méthodologiques concernent les forces intermoléculaires et interfaciales, la thérmodinamique des systèmes complexes , les procédés d'émulsification et de micro-encapsulation ainsi que les méthodes des éléments finis de frontière.
Le groupe composé de 5 permanents se structure autour de plusieurs axes de recherche principaux:
Henri Gouin, Pierre Seppecher. Temperature profile in a liquid-vapor interface near the critical point. Proceedings of the Royal Society of London. Series A, Mathematical and physical sciences, Royal Society, The, 2017, 473 (20170229), pp.1-13. Plus de détails...
Thanks to an expansion with respect to densities of energy, mass and entropy, we discuss the concept of thermocapillary fluid for inhomogeneous fluids. The non-convex state law valid for homogeneous fluids is modified by adding terms taking account of the gradients of these densities. This seems more realistic than Cahn and Hilliard's model which uses a density expansion in mass-density gradient only. Indeed, through liquid-vapor interfaces, realistic potentials in molecular theories show that entropy density and temperature do not vary with the mass density as it would do in bulk phases. In this paper, we prove using a rescaling process near the critical point that liquid-vapor interfaces behave essentially in the same way as in Cahn and Hilliard's model.
Henri Gouin, Pierre Seppecher. Temperature profile in a liquid-vapor interface near the critical point. Proceedings of the Royal Society of London. Series A, Mathematical and physical sciences, Royal Society, The, 2017, 473 (20170229), pp.1-13. <10.1098/rspa.2017.0229>. <hal-01492802v2>
Journal: Proceedings of the Royal Society of London. Series A, Mathematical and physical sciences
Gwenn Boedec, Marc Leonetti, Marc Jaeger. Isogeometric FEM-BEM simulations of drop, capsule and vesicle dynamics in Stokes flow. Journal of Computational Physics, Elsevier, 2017, 342, pp.117 - 138. Plus de détails...
We develop an algorithm for the three dimensional simulation of the dynamics of soft objects (drops, capsules, vesicles) under creeping flow conditions. Loop elements are used to describe the shape of the soft objects. This surface representation is used both for membrane solver based on finite element method (FEM) and for the fluid solver based on the boundary element method (BEM). This isogeometric analysis of the low Reynolds fluid-structure interaction problem is then coupled to high-order explicit time stepping or second-order implicit time stepping algorithm. For vesicles simulation, a preconditioner is designed for the resolution of the surface velocity incompressibility constraint, which is treated by the use of a local Lagrange multiplier. A mesh quality preserving algorithm is introduced to improve the control mesh quality over long simulation times. We test the proposed algorithm on capsule and vesicle dynamics in various flows, and study its convergence properties, showing a second-order convergence O(N-2) with mesh number of elements.
Gwenn Boedec, Marc Leonetti, Marc Jaeger. Isogeometric FEM-BEM simulations of drop, capsule and vesicle dynamics in Stokes flow. Journal of Computational Physics, Elsevier, 2017, 342, pp.117 - 138. <10.1016/j.jcp.2017.04.024>. <hal-01590257>
Xue Chen, Xun Wang, Paul G. Chen, Qiusheng Liu. Thermal effects of substrate on Marangoni flow in droplet evaporation: Response surface and sensitivity analysis. International Journal of Heat and Mass Transfer, Elsevier, 2017, 113, pp.354 - 365. Plus de détails...
In this paper, the evaporation of sessile droplets resting on a substrate with different thermal properties is numerically investigated. Computations are based on a transient axisymmetric numerical model. Special attention is paid to evaluate thermal effects of substrate on the structure of bulk fluid flow in the course of evaporation. Numerical results reveal that Marangoni convection induced by non-uniform distribution of temperature along the interface exhibits three distinctly different behaviours: inward flow, multicellular flow and outward flow, consequently resulting in different particle depositions. It is highlighted that three factors (i.e. relative thermal conductivity, relative substrate thickness and relative substrate temperature) strongly affect the flow pattern. In order to further investigate the coupling effects of different influential factors, a Kriging-based response surface method is introduced. We model the flow behaviour as a function of continuous influential factors using a limited number of computations corresponding to discrete values of the inputs. The sensitivities of the Marangoni flow are also analysed using Sobol’ index to study the coupling mechanisms of influential factors. The proposed method can be used to forecast the flow patterns for any input parameter without additional sophisticated computer simulation, and allows to confidently estimate an unknown environmental parameter.
Xue Chen, Xun Wang, Paul G. Chen, Qiusheng Liu. Thermal effects of substrate on Marangoni flow in droplet evaporation: Response surface and sensitivity analysis. International Journal of Heat and Mass Transfer, Elsevier, 2017, 113, pp.354 - 365. <10.1016/j.ijheatmasstransfer.2017.05.076>. <hal-01532757>
Journal: International Journal of Heat and Mass Transfer
Xue Chen, Paul G. Chen, Jalil Ouazzani, Qiusheng Liu. Numerical simulations of sessile droplet evaporating on heated substrate. European Physical Journal - Special Topics, EDP Sciences, 2017, 226 (6), pp.1325-1335. Plus de détails...
Motivated by the space project EFILE, a 2D axisymmetric numerical model in the framework of ALE method is developed to investigate the coupled physical mechanism during the evaporation of a pinned drop that partially wets on a heated substrate. The model accounts for mass transport in surrounding air, Marangoni convection inside the drop and heat conduction in the substrate as well as moving interface. Numerical results predict simple scaling laws for the evaporation rate which scales linearly with drop radius but follows a power-law with substrate temperature. It is highlighted that thermal effect of the substrate has a great impact on the temperature profile at the drop surface, which leads to a multicellular thermocapillary flow pattern. In particular, the structure of the multicellular flow behavior induced within a heated drop is mainly controlled by a geometric parameter (aspect ratio). A relationship between the number of thermal cells and the aspect ratio is proposed。
Xue Chen, Paul G. Chen, Jalil Ouazzani, Qiusheng Liu. Numerical simulations of sessile droplet evaporating on heated substrate. European Physical Journal - Special Topics, EDP Sciences, 2017, 226 (6), pp.1325-1335. <10.1140/epjst/e2016-60203-y>. <hal-01509843>
Journal: European Physical Journal - Special Topics
B. Bernales, Pierre Haldenwang, Pierrette Guichardon, Nelson Ibaseta. Prandtl model for concentration polarization and osmotic counter-effects in a 2-D membrane channel. Desalination, Elsevier, 2017, 404, pp.341 - 359. Plus de détails...
B. Bernales, Pierre Haldenwang, Pierrette Guichardon, Nelson Ibaseta. Prandtl model for concentration polarization and osmotic counter-effects in a 2-D membrane channel. Desalination, Elsevier, 2017, 404, pp.341 - 359. <10.1016/j.desal.2016.09.026>. <hal-01405589>
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)
