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Recherche

2 thematic axes, 6 research teams, 2 sites

The originality of M2P2 lies in its research themes in the fields of Computational Fluid Mechanics and Process Engineering. Research in mechanics and modeling is associated with a strong methodological development around calculation codes for the simulation of natural and industrial flows. In the field of process engineering, the research concerns the development of innovative processes as well as the study of the problems involved in these processes within the framework of a strong contractual activity.
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6 research teams, 2 sites

+ Technopôle Château Gombert
+ Technopôle Arbois

Publications

  • 2021
    H. Bufferand, J. Bucalossi, G. Ciraolo, G. Falchetto, A. Gallo, et al.. Progress in edge plasma turbulence modelling hierarchy of models from 2D transport application to 3D fluid simulations in realistic tokamak geometry. Nuclear Fusion, IOP Publishing, 2021, 61 (11), pp.116052. ⟨10.1088/1741-4326/ac2873⟩. ⟨hal-03377162⟩ Plus de détails...

    Progress in edge plasma turbulence modelling hierarchy of models from 2D transport application to 3D fluid simulations in realistic tokamak geometry

    This contribution presents the recent effort at CEA and French federation for Fusion to simulate edge plasma transport with the new code SOLEDGE3X. The latter can be used both as a 2D transport code or as a 3D turbulence code. It makes possible simulating edge plasma up to the first wall including the complex wall geometry. It also includes neutral recycling and impurity sputtering, seeding and transport. In order to improve turbulence description in transport simulation, a reduced model for turbulence intensity prediction has been derived and implemented, based on "kepsilon" like models from the neutral fluid community. Applications to a JET L-mode detached plasma and to a WEST plasma are used as illustration of the code abilities
    H. Bufferand, J. Bucalossi, G. Ciraolo, G. Falchetto, A. Gallo, et al.. Progress in edge plasma turbulence modelling hierarchy of models from 2D transport application to 3D fluid simulations in realistic tokamak geometry. Nuclear Fusion, IOP Publishing, 2021, 61 (11), pp.116052. ⟨10.1088/1741-4326/ac2873⟩. ⟨hal-03377162⟩
    Journal: Nuclear Fusion
    Date de publication: 13-10-2021
    Auteurs:
    Liste des documents:
    Digital object identifier (doi): http://dx.doi.org/10.1088/1741-4326/ac2873
    Voir la publication sur Hal
  • 2021
    Pierre Magnico. Molecular dynamics study on water and hydroxide transfer mechanisms in PSU-g-alkyl-TMA membranes at low hydration: Effect of side chain length. International Journal of Hydrogen Energy, Elsevier, 2021, 46 (68), pp.33915-33933. ⟨10.1016/j.ijhydene.2021.07.081⟩. ⟨hal-03358207⟩ Plus de détails...

    Molecular dynamics study on water and hydroxide transfer mechanisms in PSU-g-alkyl-TMA membranes at low hydration: Effect of side chain length

    Molecular dynamics simulations with anion exchange membranes (alkyl trimethyl ammonium grafted onto polysulfone) are performed to investigate the influence of the spacer length on the transport properties, on the molecular exchange mechanisms between the functional group and the aqueous phase and on the hydrogen bond network. This is especially insightful that in this work the hydration number is small. In this condition the aqueous phase must be thought as an assembly of small clusters. The results show an unexpected dependence of the water and hydroxide (OH) diffusivity on the temperature and the water uptake. The distribution of the cluster size bonded to OH explain partially the OH diffusivity. “Hopping” and “caging” motions are observed with the self-part of the Van Hove functions even at high temperature. The characteristic time of the survival probability correlation function around the functional groups is a decreasing function of the alkyl length.
    Pierre Magnico. Molecular dynamics study on water and hydroxide transfer mechanisms in PSU-g-alkyl-TMA membranes at low hydration: Effect of side chain length. International Journal of Hydrogen Energy, Elsevier, 2021, 46 (68), pp.33915-33933. ⟨10.1016/j.ijhydene.2021.07.081⟩. ⟨hal-03358207⟩
    Journal: International Journal of Hydrogen Energy
    Date de publication: 01-10-2021
    Auteurs:
    Liste des documents:
    Digital object identifier (doi): http://dx.doi.org/10.1016/j.ijhydene.2021.07.081
    Voir la publication sur Hal
  • 2021
    S. Baschetti, H. Bufferand, G. Ciraolo, Ph Ghendrih, E. Serre, et al.. Self-consistent cross-field transport model for core and edge plasma transport. Nuclear Fusion, IOP Publishing, 2021, 61 (10), pp.106020. ⟨10.1088/1741-4326/ac1e60⟩. ⟨hal-03380310⟩ Plus de détails...

    Self-consistent cross-field transport model for core and edge plasma transport

    A two-equation model to self-consistently determine cross-field fluxes in the edge and scrape-off layer region of diverted plasma is used to complete 2D mean-field edge transport description of plasma wall interaction. Inspired by the Reynolds Average Navier-Stokes simulations for neutral fluids, this model is based on the local evolution of the turbulent kinetic energy κ and its dissipation rate ε. These two equations are algebraically derived for RANS modeling and are very slightly modified and adapted to describe self-consistent plasma turbulent transport. The general features of the model are discussed and bridged to the well-known predatorprey and quasilinear models commonly used to investigate plasma transport. Specific closures are proposed based on the interchange turbulence. Results of the 1D model are confronted to experimental evidence by analyzing the computed SOL width and comparing the results to the existing scaling law for L-mode plasmas. Introducing a dependence on the shear of large scale flows, typically the zonal flows, 1D simulations can exhibit an H-mode like transition when increasing the input power, generating an increased stored energy thanks to an interface barrier located at the separatrix. Further 2D plasma-wall interaction simulations for WEST are analyzed that show a good match with the experimental profiles, as well as a ballooned transport driving turbulent transport in the divertor SOL and nearly no transport in the private flux region. The SOL width of WEST is also recovered. These results show the remarkable capability of the κ-ε model to capture key aspects of the physics of turbulent transport throughout the plasma knowing that a unique scalar free parameter is available to tune cross field transport in the whole 2D cross section of the plasma.
    S. Baschetti, H. Bufferand, G. Ciraolo, Ph Ghendrih, E. Serre, et al.. Self-consistent cross-field transport model for core and edge plasma transport. Nuclear Fusion, IOP Publishing, 2021, 61 (10), pp.106020. ⟨10.1088/1741-4326/ac1e60⟩. ⟨hal-03380310⟩
    Journal: Nuclear Fusion
    Date de publication: 17-09-2021
    Auteurs:
    Liste des documents:
    Digital object identifier (doi): http://dx.doi.org/10.1088/1741-4326/ac1e60
    Voir la publication sur Hal
  • 2021
    S. Di Genova, A. Gallo, N. Fedorczak, H. Yang, G. Ciraolo, et al.. Modelling of tungsten contamination and screening in WEST plasma discharges. Nuclear Fusion, IOP Publishing, 2021, 61 (10), pp.106019. ⟨10.1088/1741-4326/ac2026⟩. ⟨hal-03380329⟩ Plus de détails...

    Modelling of tungsten contamination and screening in WEST plasma discharges

    The WEST experiment is currently operating with tungsten plasma-facing components and testing ITER-like divertor monoblocks. In order to support WEST experiments interpretation, numerical analyses were carried out. Starting from WEST experimental data, realistic background plasma conditions were reproduced through SolEdge-EIRENE and used as input for ERO2.0 simulations to investigate tungsten migration. Tungsten contamination due to the different plasma-facing components was modelled under different plasma conditions, highlighting a non-negligible contribution of tungsten coming from the tokamak main chamber. Tungsten penetration factor was computed and used as an indication for tungsten screening by the background plasma at the different tokamak plasma-facing components. Simulations showed the main chamber components to be very weakly screened. Light impurities charge was showed to influence not only tungsten sputtering, but also its probability to enter the confined plasma. Simulations results indicated that even when the tungsten source is not heavily influenced by self-sputtering, contamination of the confined plasma can be strongly impacted by it in low density background plasma conditions. Finally, a one-to-one comparison between tungsten visible spectroscopy at the lower divertor from experimental data and from synthetic diagnostics was performed, showing that it is possible to reproduce a realistic lower divertor signal following experimental evidence on light impurities asymmetry between the targets.
    S. Di Genova, A. Gallo, N. Fedorczak, H. Yang, G. Ciraolo, et al.. Modelling of tungsten contamination and screening in WEST plasma discharges. Nuclear Fusion, IOP Publishing, 2021, 61 (10), pp.106019. ⟨10.1088/1741-4326/ac2026⟩. ⟨hal-03380329⟩
    Journal: Nuclear Fusion
    Date de publication: 13-09-2021
    Auteurs:
    Liste des documents:
    Digital object identifier (doi): http://dx.doi.org/10.1088/1741-4326/ac2026
    Voir la publication sur Hal
  • 2021
    Johan Degrigny, Shang-Gui Cai, Jean-François Boussuge, Pierre Sagaut. Improved wall model treatment for aerodynamic flows in LBM. Computers and Fluids, Elsevier, 2021, 227, pp.105041. ⟨10.1016/j.compfluid.2021.105041⟩. ⟨hal-03326170⟩ Plus de détails...

    Improved wall model treatment for aerodynamic flows in LBM

    The article deals with an improved treatment of wall models for the simulation of turbulent flows in the framework of Immersed Wall Boundaries on Cartesian grids. The emphasis is put on the implementa-tion in a Lattice-Boltzmann Method solver without loss of generality, since the proposed approach can be used in Navier-Stokes-based solvers in a straightforward way. The proposed improved wall model im-plementation relies on the combination of several key elements, namely i) the removal of grid points too close to the solid surface and ii) an original computation of wall normal velocity gradient and iii) the interpolation scheme. The new method is successfully assessed considering URANS simulations focusing on steady solutions of the Zero Pressure Gradient turbulent flat plate boundary layer and the turbulent flow around a NACA0012 airfoil at several angles of attack.
    Johan Degrigny, Shang-Gui Cai, Jean-François Boussuge, Pierre Sagaut. Improved wall model treatment for aerodynamic flows in LBM. Computers and Fluids, Elsevier, 2021, 227, pp.105041. ⟨10.1016/j.compfluid.2021.105041⟩. ⟨hal-03326170⟩
    Journal: Computers and Fluids
    Date de publication: 01-09-2021
    Auteurs:
    Digital object identifier (doi): http://dx.doi.org/10.1016/j.compfluid.2021.105041
    Voir la publication sur Hal
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All lab's publications

Actualités scientifiques

Actualités Archives récentes
Février 2022 - Lattice-Boltzmann methods for compressible flows / PhD defense Gabriel Farag
Doctorant : Fabriel FARAG

Date de soutenance : le 4 février 2022 à 14h00 ; Amphi 3 Centrale Marseille

Abstract  : Since the late 1970's, computational fluid dynamics solvers became essentials due to increasingly complex applications requiring fluid solutions. The small scales necessary for industrial applications often need a very fine grid or very small timestep. This dramatically increases the computational cost of nowadays simulations. To design more computationally efficient solvers, a popular approach is to use Lattice-Boltzmann methods. Originating from the kinetic theory of gases, this method have gained a tremendous popularity among fluid dynamicists due to its cheap and easily implemented collide & stream algorithm. However, its intrinsic assumptions confines classical Lattice-Boltzmann solvers to weakly compressible flows. Yet, some compressible models have been proposed. The purpose of this manuscript is to improve the robustness as well as accuracy of compressible Lattice-Boltzmann models. To this end, the Lattice-Boltzmann method is fully reinterpreted as a numerical scheme. This allows a straightforward and parsimonious derivation of the equivalent Navier-Stokes-Fourier system using the sole assumption of a negligible timestep. Using this formalism, the order of accuracy is shown to depend on the collision kernel, as well as the mechanical constitutive model. Various models are investigated and we show that the Knudsen number is not the sole parameter controlling the consistency with the Navier-Stokes-Fourier model. Additionally, capabilities of the entropy equation to model low supersonic flows is explained through standard shock wave theory arguments. A MUSCL-Hancock scheme is employed to discretize the entropy equation and improve both stability and accuracy compared to previous schemes. Equipped with this new formalism, a compressible pressure-based model is proposed and validated on various supersonic test cases. Then, we unify all compressible models proposed by our group under a single formalism and investigate the differences and optimal choices for the various degrees of freedom of our family of models. Finally, this unified model is validated on high supersonic smooth flows and low supersonic shocked flows. 

Jury
Directeur de these M. Pierre BOIVIN CNRS / M2P2
CoDirecteur de these  M. Guillaume CHIAVASSA  Centrale Marseille
Rapporteur M. Rémi ABGRALL Univertität Zürich
Rapporteur M. Jonas LATT Université de Genève
Examinateur Mme Paola CINNELLA Sorbonne Université
Examinateur M. Manfred KRAFCZYK Technische Universität Braunschweig
Examinateur M. Pierre SAGAUT Aix-Marseille Université / M2P2
15 Décembre 2021 - Study of the energy potential for a water supply network / Soutenance de thèse Gautier HYPOLITE
Doctorant : Gautier HYPOLITE

Date de soutenance :  mercredi 15 Décembre 2021 à 14:00 (Amphithéâtre du CEREGE / Technopôle de l'Arbois-Méditerranée, BP80, 13545 Aix-en-Provence)

Abstract : In order to reduce fossil fuels consumption for heating and cooling, different heat sources can be considered. Given theamount of water they carry, water supply systems can play this role and appear to have a high thermal potential. To date, this source has not been used: the main problem is to optimize the sizing of the equipment according to the temporal variability of water flow, water temperature, and the heat (or cold) demand. A first task is to evaluate the available thermal energy. For this purpose, a model based on a minimum number of measurements has been developed. It allows to determine the annual evolution of the temperature and the flow at each point of the network. Temporal variations of water demand and soil surface temperature are taken into account. The ground surface temperature is obtained by satellite measurements. Water flow, soil temperature and water temperature measurements in the network are performed to validate the models and the soil thermal properties. A simulation of the water system hydraulic and thermal behavior is performed for the year 2018 and compared to these measurements. The impact on the water temperature of adding several heat exchanges to the network is then evaluated with this model. In this study, the potential of a raw water system (composed of 5000 km of pipes, and transporting 200 million cubic meters of water per year in the south of France) is studied. As the temperature, the flow rate and heat demand are highly time dependent, a method has been developed to optimize the sizing and location of the exchange systems. This method is based on minimizing the entropy generation in the heat exchanger between the water pipes and the users. The dynamic behavior of a simple heat exchanger (concentric tube) between the network and the user is modeled (pressure profile and fluids and wall temperature calculation). The value of entropy generation due to temperature difference and pressure drop in the exchanger is obtained in transient operation, this value is used as an objective function for the optimization. The results based on the cooling of a data center show that the entropy gain is significant when the optimal size of the heat exchanger is chosen. The use of the raw water network connected to a reversible heat pump for heating and cooling a building has also been studied and results in a high gain compared to an air source heat pump. 

Jury :
Directeur de these M. Jean-Henry FERRASSE Aix Marseille Université
Rapporteur M. Clausse MARC INSA LYON
Rapporteur M. Francois LANZETTA Unversité de Franche-Conté
Examinateur Mme Nathalie MAZET Université de Perpignan
CoDirecteur de these M. Olivier BOUTIN Aix Marseille Université
Examinateur M. Sylvain SERRA LaTEP
26 November 2021 - Ultrafiltration as urban wastewater tertiary treatment for water reuse at semi-industrial scale / Thesis defense Jiaqi YANG
Doctorant : Jiaqi YANG 

Date de soutenance :   Vendredi 26 November 2021 à 10h (Grand Amphithéâtre du CEREGE - Site de l'Arbois) 

Abstract : Water reuse is a sustainable development strategy that benefits society and future generations. In this study, a semi-industrial ultrafiltration (UF) pilot plant established at the outlet of a wastewater treatment plant was studied to assess its feasibility and sustainability for non-potable water reuse. The optimization of operating conditions made it possible to support reliable and sustainable filtration performance, the operating conditions were optimized through comparative analysis in terms of water quality, permeability variation, irreversible fouling management, and water recovery rate. The best conditions were J80t40BW1/3 (flux of 80 L·h−1·m−2, filtration cycle time of 40 min, 1 air backwash followed by 3 classical backwashes), J60t60BW1/4 and J60t60BW1/3. The long-term study on condition J60t60BW1/3 provides sustainable and adaptable filtration performance regardless of the temperature and feed water quality variation. In addition, the air backwashes enabled excellent reversibility of membrane fouling, which was approximately 1.25 to 2 times higher than of classic backwashes in average. The quality of the UF permeate was good enough to be reused in non-potable purposes as it met reuse guidelines of the World Health Organization, reuse standards of France, and the most recent EU regulation for agricultural irrigation. A specific study of membrane cleaning has shown that the addition of NaClO in backwash water can greatly increase cleaning efficiency of air backwashes. Finally, the calculation of the capital expenditure (CAPEX) and operational expenditure (OPEX) of the UF system under optimized conditions gives a profitable net unit price for water production. Through this thesis, UF is confirmed to be a reliable tertiary treatment for water reuse and the results give operational indications for the industrial scale and provides proposals for the management of membrane fouling by air backwash with chemical assistance. 

Jury :
Annabelle COUVERT (Examinateur) / Professeur des Universités, ISCR, ENSC Rennes
Lionel ERCOLEI (Membre invité) /Directeur de l’Innovation, Société des Eaux de Marseille Métropole
Marc HÉRAN (Rapporteur) / Professeur des Universités, IEM, Université de Montpellier
Stéphanie LABORIE (Rapporteur) / Maître de Conférences HDR, TBI, INSA Toulouse
Mathias MONNOT (Co-Directeur de Thèse) / Maître de Conférences, M2P2, Aix-Marseille Université
Philippe MOULIN (Directeur de Thèse) / Professeur des Universités, M2P2, Aix-Marseille Université
Patrick SAUVADE (Membre Invité) / Product manager, Aquasource, Toulouse
9 Novembre 2021 - Vers la prédiction numérique du tremblement basse vitesse des avions civils: traitement de paroi amélioré pour la méthode Boltzmann sur réseau / Soutenance de thèse de Johan DEGRIGNY
Doctorant : Johan DEGRIGNY

Date de soutenance : Mardi 9 Novembre 2021 à 14:00, CERFACS, Toulouse / Salle administration 

Résumé :
La CFD (mécanique des fluides numérique) est un outil fiable et répandu en aérodynamique aéronautique pour prédire les écoulements dans des conditions proches des points de croisière nominaux. La prédiction fidèle de phénomènes aérodynamiques instationnaires impliquant des décollements massifs échappe encore aux calculs effectués à l'aide de la stratégie de modélisation de turbulence RANS (Reynolds-Averaged Navier-Stokes), qui est la norme dans le secteur. Le tremblement basse vitesse -- l'excitation mécanique de certains composants (l'empennage, par exemple) par le sillage d'un décollement localisé sur un composant en amont (la voilure, par exemple) -- tombe dans cette catégorie. Il est attendu des calculs résolvant les grandes échelles turbulentes qu'ils comblent cette lacune et qu'ils permettent ainsi l'élaboration de meilleurs aéronefs de façon plus économique et avec des cycles de conceptions plus courts. La LBM (méthode de Boltzmann sur réseau) semble être une bonne candidate pour relever le défi d'effectuer des calculs résolvant les grandes échelles turbulentes dans le processus de conception d'aéronefs. La modélisation de paroi, qui consiste à modéliser l'écoulement dans la zone interne de la couche limite, est crucial pour la LBM, plus encore que pour d'autres méthodes numériques. En effet l'utilisation de maillages cartésiens rend les calculs pleinement résolus de couches limites à fort nombre de Reynolds utopiques (même avec la modélisation RANS), et complique grandement la modélisation de paroi. De telles implémentations sont appelées "traitements de paroi". Ce travail repose sur ProLB, un solveur LBM développé par et appartenant à un groupement dont fait partie Airbus. Un traitement de paroi amélioré est développé dans ProLB à partir du traitement existant afin d'étendre le potentiel du solveur pour les écoulements attachés. Ces derniers sont un enjeu majeur pour le tremblement basse vitesse, au même titre que les écoulements décollés. Quatre éléments complémentaires sont introduits: un schéma d'entrée pour le modèle de paroi contournant l'interpolation du champ de vitesse proche des parois, la prise en compte du gradient discrétisé du modèle de paroi dans la condition limite LBM, l'élimination des noeuds trop proches des parois par rapport à la taille de maille locale et une précaution spécifique pour les mailles en surplomb au niveau des arrêtes vives. Le traitement de paroi amélioré est calibré et validé par des calculs RANS avec un simple modèle de paroi algébrique sur une plaque plane alignée avec le maillage en l'absence de gradient de pression et sur un profil d'aile NACA0012. La régularité des frottements et pressions pariétaux sont bien meilleurs qu'avec le traitement de base. La précision des résultats est aussi améliorée, dans les limites de la simplicité du modèle de paroi utilisé; les décollements ne sont pas correctement prédits. Le formalisme LES (simulation aux grandes échelles) donne un cadre pour la résolution des grandes échelles turbulentes mais sa mise en oeuvre est compliquée pour des applications réalistes. Les modèles hybrides RANS-LES comme les dérivés de la DES (Detached Eddy Simulation), qui combinent les avantages de ces deux stratégies de modélisation de la turbulence, sont donc plus prometteurs dans le cadre industriel. Le modèle perfectionné ZDES mode 2 (2020) publié récemment est donc implémenté dans ProLB, et sa mise en application en conjonction avec le traitement de paroi amélioré est montrée sur un profil d'aile hypersustenté et une configuration générique d'avion hypersustenté. 

Jury
Directeur de these M. Pierre SAGAUT Aix Marseille Université / M2P2
Rapporteur M. Eric LAMBALLAIS Université de Poitiers
Rapporteur M. Sébastien DECK ONERA
Examinateur M. Damiano CASALINO Delft University of Technology
Examinateur Mme Salvetti MARIA VITTORIA Università di Pisa
17 septembre 2021 - Rétention de virus par ultrafiltration : application à la production d'eau potable / Soutenance de thèse de Nolwenn JACQUET
Doctorante : Nolwenn JACQUET 

Date de soutenance : Vendredi 17 septembre 2021 à 9:00 ; Technopôle de l'Arbois-Méditerranée ; CEREGE, Amphithéâtre.

Résumé :
Lors de la production d'eau potable, produire une eau exempte de tout microorganisme pathogène pour l'homme est une priorité afin d'éviter tout risque sanitaire. Le traitement de ces différents pathogènes est assuré en usine par un traitement multi barrières composé de différents procédés de désinfection comme le chlore, les rayonnements UV et/ou l'ozone. Les procédés membranaires peuvent également compléter cette désinfection sans ajout de corps tiers. Lors de cette thèse, le procédé d'ultrafiltration a été étudié vis-à-vis de la rétention de deux virus entériques pathogènes : un adénovirus (AdV 41) et un entérovirus (CV-B5). La rétention de ces virus a pu être comparée à celle d'autres composés comme les bactériophages MS2 ou les nanoparticules fluorescentes, afin d'évaluer leur potentiel comme modèle de rétention virale. Différentes conditions opératoires ont pu être étudiées afin de mettre en évidence les potentielles différences entre les manipulations en laboratoire et la réalité industrielle. La rétention virale apparait fortement impactée par la concentration en amont de la membrane et/ou la concentration d'alimentation. Si les abattements viraux calculés pour de fortes concentrations virales d'alimentation peuvent atteindre, en accord avec les données fabricant, 3 à plus de 5 log selon les membranes et les virus étudiés, des abattements inférieurs à 1 log sont obtenus pour les plus faibles charges virales étudiées, représentatives de la réalité de la contamination des ressources en eau. L'impact de la membrane mais également de son vieillissement sur la rétention virale a également été étudié par rapport à un vieillissement au NaOCl et un vieillissement réel en usine. Si l'exposition au NaOCl entraîne bien des dégradations du matériau membranaire, c'est l'apparition du colmatage après les cycles de filtrations en usine qui influence fortement la rétention virale avec le vieillissement. L'osmose inverse basse pression a également été étudiée et comparée à l'ultrafiltration. Ces membranes denses permettent ainsi d'améliorer la rétention virale, bien qu'elles ne permettent pas une rétention totale. 

Jury
Directeur de these M. Philippe MOULIN Aix Marseille Université
M. Yvan WYART Aix Marseille Université
M. Laurent MOULIN Eau de Paris
Examinateur Mme Soizick LE GUYADER IFREMER
Rapporteur Mme Corinne CABASSUD INSA TOULOUSE
Rapporteur M. Benoit TEYCHENE IC2MP
All PhD defenses