Cerfacs Entrez dans le monde de la haute performance...

Le Cerfacs en bref

Centre de recherche fondamentale et appliquée spécialisé dans la modélisation et la simulation numériques, également centre de formation avancée, le Cerfacs, par ses moyens et son savoir-faire en calcul haute performance, traite des grands problèmes scientifiques et techniques de recherche publique et industrielle sur les secteurs suivants: AERONAUTIQUE&AUTOMOBILEESPACEENERGIEENVIRONNEMENT&CLIMAT
Ses effectifs sont de l'ordre de 100-150 chercheurs, ingénieurs et administratifs.

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LES ACTUALITÉS

Le CERFACS participe à l’initiative Allons-y à vélo !

16 janvier 2019

Le CERFACS participe à l'initiative Allons-y à vélo ! (AYAV). La prochaine édition aura lieu du 21 au 25 Janvier. Allons-y à vélo c'est l'occasion de laisser sa voiture au garage, de faire travailler ses gambettes et de prendre un bol d'air frais ! En...

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Le Cerfacs récompensé par deux prix à la journée R&T partenaires de Safran Aircraft Engines le 17 décembre 2018

19 décembre 2018

Le Cerfacs a participé à la journée R&T Safran Aircraft Engines, journée durant laquelle Safran AE et leurs partenaires ont présenté leurs travaux en recherche et développement. Le Cerfacs a présenté sous forme de posters une vue générale des activités...

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Toute l'actualité

NOS PUBLICATIONS

Collin-Bastiani, F., Marrero-Santiago, J., Riber, E., Cabot, G., Renou, B. and Cuenot, B. (2019) A joint experimental and numerical study of ignition in a spray burner, Proceedings of the Combustion Institute, 37 (4), pp. 5047-5055, doi:10.1016/j.proci.2018.05.132

[url] [doi]

@ARTICLE{AR-CFD-19-25, author = {Collin-Bastiani, F. and Marrero-Santiago, J. and Riber, E. and Cabot, G. and Renou, B. and Cuenot, B. }, title = {A joint experimental and numerical study of ignition in a spray burner}, year = {2019}, number = {4}, volume = {37}, pages = {5047-5055}, doi = {10.1016/j.proci.2018.05.132}, journal = {Proceedings of the Combustion Institute}, abstract = {Partly due to stringent restrictions on pollutant emissions, aeronautical engine manufacturers target lean operating conditions which raise new difficulties such as combustion stability as well as ignition and re- ignition at high altitude. The injection of liquid fuel introduces additional complexity due to the spray-flame interaction. It is then crucial to better understand the physics behind these phenomena and to develop the capacity to predict them in an industrial context. In this work, a comprehensive joint experimental and nu- merical investigation of the academic swirled-confined version of the KIAI-Spray burner is carried out. Experimental diagnostics, such as Phase Doppler Anemometry (PDA), Planar Laser Induced Fluorescence (OH-PLIF), high-speed visualization and high-speed particle image velocimetry (HS-PIV), together with Large Eddy Simulations coupled to Discrete Particle Simulations are used to study spray flame structure and spray ignition. The analysis of the swirled-stabilized spray flame highlights the main effects of the presence of droplets on the turbulent combustion, and the complementarity and validity of the joint experiment and simulation approach. Ignition sequences are then studied. Both experiment and simulation show the same behaviors, and relate the flame kernel evolution and the possible success of ignition to the local non reacting flow properties at the sparking location, in terms of turbulence intensity and presence of droplets}, keywords = {Spray flame, Ignition, Laser diagnostics, Large Eddy Simulation}, url = {https://doi.org/10.1016/j.proci.2018.05.132}}

Wissocq, G., Sagaut, P. and Boussuge, J. -F. (2019) An extended spectral analysis of the lattice Boltzmann method: modal interactions and stability issues, Journal of Computational Physics, 380 (March), pp. 311-333, doi:10.1016/j.jcp.2018.12.015

[url] [doi]

@ARTICLE{AR-CFD-19-29, author = {Wissocq, G. and Sagaut, P. and Boussuge, J.-F. }, title = {An extended spectral analysis of the lattice Boltzmann method: modal interactions and stability issues}, year = {2019}, number = {March}, volume = {380}, pages = {311-333}, doi = {10.1016/j.jcp.2018.12.015}, journal = {Journal of Computational Physics}, abstract = {An extension of the von Neumann linear analysis is proposed for the study of the discrete-velocity Boltzmann equation (DVBE) and the lattice Boltzmann (LB) scheme. While the standard technique is restricted to the investigation of the spectral radius and the dissipation and dispersion properties, a new focus is put here on the information carried by the modes. The technique consists in the computation of the moments of the eigenvectors and their projection onto the physical waves expected by the continuous linearized Navier–Stokes (NS) equations. The method is illustrated thanks to some simulations with the BGK (Bhatnagar–Gross–Krook) collision operator on the D2Q9 and D2V17 lattices. The present analysis reveals the existence of two kinds of modes: non-observable modes that do not carry any macroscopic information and observable modes. The latter may carry either a physical wave expected by the NS equations, or an unphysical information. Further investigation of modal interactions highlights a phenomenon called curve veering occurring between two observable modes: a swap of eigenvectors and dissipation rate is observed between the eigencurves. Increasing the Mach number of the mean flow yields an eigenvalue collision at the origin of numerical instabilities of the BGK model, arising from the error in the time and space discretization of the DVBE.}, keywords = {Lattice Boltzmann, von Neumann analysis}, url = {https://doi.org/10.1016/j.jcp.2018.12.015}}

Collin-Bastiani, F., Vermorel, O., Lacour, C., Lecordier, B. and Cuenot, B. (2019) DNS of spark ignition using Analytically Reduced Chemistry including plasma kinetics, Proceedings of the Combustion Institute, 37 (4), pp. 5057-5064, doi:10.1016/j.proci.2018.07.008

[url] [doi]

@ARTICLE{AR-CFD-19-26, author = {Collin-Bastiani, F. and Vermorel, O. and Lacour, C. and Lecordier, B. and Cuenot, B. }, title = {DNS of spark ignition using Analytically Reduced Chemistry including plasma kinetics}, year = {2019}, number = {4}, volume = {37}, pages = {5057-5064}, doi = {10.1016/j.proci.2018.07.008}, journal = {Proceedings of the Combustion Institute}, abstract = {In order to guarantee good re-ignition capacities in case of engine failure during flight, it is of prime interest for engine manufacturers to understand the physics of ignition from the spark discharge to the full burner lightning. During the ignition process, a spark plug delivers a very short and powerful electrical discharge to the mixture. A plasma is first created before a flame kernel propagates. The present work focuses on this still misunderstood first instants of ignition, i.e., from the sparking to the flame kernel formation. 3D Direct Numerical Simulations of propane-air ignition sequences induced by an electric discharge are performed on a simple anode-cathode set-up. An Analytically Reduced Chemistry (ARC) including 34 transported species and 586 irreversible reactions is used to describe the coupled combustion and plasma kinetics. The effect of plasma chemistry on the temperature field is found to be non-negligible up to a few microseconds after the spark due to endothermic dissociation and ionization reactions. However, its impact on the subsequent flame kernel development appears to be weak in the studied configuration. This tends to indicate that plasma chemistry does not play a key role in ignition and may be omitted in numerical simulations.}, keywords = {Spark ignition, Plasma kinetics, Analytically Reduced Chemistry}, url = {https://doi.org/10.1016/j.proci.2018.07.008}}

Gallen, L., Felden, A., Riber, E. and Cuenot, B. (2019) Lagrangian tracking of soot particles in LES of gas turbines, Proceedings of the Combustion Institute, 37 (4), pp. 5429-5436, ISSN 1540-7489, doi:10.1016/j.proci.2018.06.013

[pdf] [url] [doi]

@ARTICLE{AR-CFD-19-27, author = {Gallen, L. and Felden, A. and Riber, E. and Cuenot, B. }, title = {Lagrangian tracking of soot particles in LES of gas turbines}, year = {2019}, number = {4}, volume = {37}, pages = {5429-5436}, issn = {1540-7489}, doi = {10.1016/j.proci.2018.06.013}, journal = {Proceedings of the Combustion Institute}, keywords = {Soot particles, Lagrangian tracking, Large Eddy Simulation, Gas turbine}, pdf = {https://cerfacs.fr/wp-content/uploads/2018/09/CFD_GALLEN_PROCI2018.pdf}, url = {https://doi.org/10.1016/j.proci.2018.06.013}}

Rochette, B., Riber, E. and Cuenot, B. (2019) Effect of non-zero relative velocity on the flame speed of two-phase laminar flames, Proceedings of the Combustion Institute, 37 (3), pp. 3393-3400, doi:10.1016/j.proci.2018.07.100

[url] [doi]

@ARTICLE{AR-CFD-19-28, author = {Rochette, B. and Riber, E. and Cuenot, B. }, title = {Effect of non-zero relative velocity on the flame speed of two-phase laminar flames}, year = {2019}, number = {3}, volume = {37}, pages = { 3393-3400}, doi = {10.1016/j.proci.2018.07.100}, journal = {Proceedings of the Combustion Institute}, abstract = {A numerical study of one-dimensional n-heptane/air spray flames is presented. The objective is to evaluate the flame propagation speed in the case where droplets evaporate inside the reaction zone with possibly non-zero relative velocity. A Direct Numerical Simulation approach for the gaseous phase is coupled to a discrete particle Lagrangian formalism for the dispersed phase. A global two-step n-heptane/air chemical mechanism is used. The eects of initial droplet diameter, overall equivalence ratio, liquid loading and relative velocity between gaseous and liquid phases on the laminar spray flame speed and structure are studied. For lean premixed cases, it is found that the laminar flame speed decreases with increasing initial droplet diameter and relative velocity. On the contrary, rich premixed cases show a range of diameters for which the flame speed is enhanced compared to the corresponding purely gaseous flame. Finally, spray flames controlled by evaporation always have lower flame speeds. To highlight the controlling parameters of spray flame speed, approximate analytical expressions are proposed, which give the correct trends of the spray flame propagation speed behaviour for both lean and rich mixtures}, keywords = { Direct Numerical Simulation, Lagrangian particle tracking, Spray flame, Laminar flame}, url = {https://doi.org/10.1016/j.proci.2018.07.100}}

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LE CERFACS RECRUTE

Chaîne ensembliste de prévision des crues. Modélisation hydrologique des bassins versants à partir des prévisions de pluies AROME et étude de quantification des incertitudes

 

Ce sujet est proposé dans le cadre d'une collaboration entre le CECI, le LHSV, EDF, le réseau CEREMA/SCHAPI/SPC et le CNRM. L'objectif est de...Lire plus


Prédiction et reconstruction de données hydrauliques par apprentissage machine

 

Sujet du stage Ce sujet est proposé dans le cadre d'une collaboration entre le CERFACS et EDF (LNHE). Le stage se déroulera au CERFACS. Le Centre...Lire plus

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