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ROLAND GLOWINSKI CONFERENCE IN PARIS FROM JULY 5th to 7th

CERFACS |  4 July 2022

CERFACS will participate to the Paris meeting dedicated to the memory of Roland Glowinski from July 5th to 7th. Thierry Poinsot will present the advances of HPC in the field of energy and combustion. Roland Glowinski was CERFACS direcfor for 3 years in the 90s and largely shaped present activities of our research center.Read more


TERATEC award, innovation category

CERFACS |  27 June 2022

The TERATEC 2022 Simulation and Digital Technologies Trophy, innovation category, was awarded to Catherine Lambert on June 14 during the TERATEC 2022 Forum. This trophy rewards CERFACS and Safran for the development of the AVIP code capable of simulating new generations of electric motors for satellite propulsion. Thanks to the use of unstructured meshes and innovative numerical techniques, AVIP makes it possible to build digital twins of real engines. Congratulations to all who contributed to the project: Willca Villafana (Cerfacs), Guillaume Bogoposlky (Safran), Benjamin Laurent (Safran), Olivier Vermorel (Cerfacs), Bénédicte Cuenot (Cerfacs) And a big thank you to our partners: INRIA and Ecole Polytechnique (POSEIDON project)  Read more

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RESEARCH PUBLICATIONS

Giraud, L., Jing, Y-F. and Xiang, Y. (2022) A Block Minimum Residual Norm Subspace Solver with Partial Convergence Management for Sequences of Linear Systems, SIAM Journal on Matrix Analysis and Applications, 43 (2), pp. 710-739, doi:10.1137/21M1401127

[url] [doi]

@ARTICLE{AR-PA-22-60, author = {Giraud, L. and Jing, Y-F. and Xiang, Y. }, title = {A Block Minimum Residual Norm Subspace Solver with Partial Convergence Management for Sequences of Linear Systems}, year = {2022}, number = {2}, volume = {43}, pages = {710-739}, doi = {10.1137/21M1401127}, journal = {SIAM Journal on Matrix Analysis and Applications}, abstract = {We are concerned with the iterative solution of linear systems with multiple right-hand sides available one group after another with possibly slowly varying left-hand sides. For such sequences of linear systems, we first develop a new block minimum norm residual approach that combines two main ingredients. The first component exploits ideas from GCRO-DR [Parks et al., SIAM J. Sci. Comput., 28 (2006), pp. 1651--1674], enabling us to recycle information from one solve to the next. The second component is the numerical mechanism for managing the partial convergence of the right-hand sides, referred to as inexact breakdown detection in IB-BGMRES [Robbé and Sadkane, Linear Algebra Appl., 419 (2006), pp. 265--285], that enables the monitoring of the rank deficiency in the residual space basis expanded blockwise. Next, for the class of block minimum norm residual approaches that relies on a block Arnoldi-like equality between the search space and the residual space (e.g., any block GMRES or block GCRO variants), we introduce new search space expansion policies defined on novel criteria to detect the partial convergence. These novel detection criteria are tuned to the selected stopping criterion and targeted convergence threshold to best cope with the selected normwise backward error stopping criterion, enabling us to monitor the computational effort while ensuring the final accuracy of each individual solution. Numerical experiments are reported to illustrate the numerical and computational features of both the new block Krylov solvers and the new search space block expansion polices.}, keywords = {hal-03546496v2}, url = {https://hal.inria.fr/hal-03546496v2}}

Crespo-Anadon, J., Benito-Parejo, C. J., Richard, S., Riber, E., Cuenot, B., Strozzi, C., Sotton, J. and Bellenoue, M. (2022) Experimental and LES investigation of ignition of a spinning combustion technology combustor under relevant operating conditions, Combustion and Flame, 242, pp. 112204, doi:10.1016/j.combustflame.2022.112204

[pdf] [doi]

@ARTICLE{AR-CFD-22-61, author = {Crespo-Anadon , J. and Benito-Parejo, C.J. and Richard, S. and Riber, E. and Cuenot, B. and Strozzi, C. and Sotton, J. and Bellenoue, M. }, title = {Experimental and LES investigation of ignition of a spinning combustion technology combustor under relevant operating conditions}, year = {2022}, volume = {242}, pages = { 112204}, doi = {10.1016/j.combustflame.2022.112204}, journal = {Combustion and Flame}, abstract = {SAFRAN Helicopter Engines has developed the spinning combustion technology in which the burnt gases from one injector travel tangentially along the combustor annulus towards the neighboring injectors. Compared to a conventional design, this arrangement modifies the ignition process, which is a critical phase for aeroengines. In order to understand the ignition process in this technology, experiments and Large-Eddy Simulation (LES) have been performed in a cylindrical combustion chamber where the flow is injected tangentially (named Radius chamber). Three cases are considered with different strain and turbulence levels representative of real combustor flows. Micro calorimetry and the Background-Oriented Schlieren technique allows for detailed temporal measurements of energy deposited in the flame kernel. Pressure measurement and Schlieren imaging are used to study the flame propagation. LES are performed with a 19-species and 184-reactions analytically-reduced chemistry together with the thickened flame approach allowing the description of the first instants of ignition in a quasi-DNS mode and ensuing flame propagation. Both a static and dynamic formulations of the wrinkling factor to describe sub-grid scale chemistry-turbulence interaction are used. Results show that LES is able to capture the flame kernel formation and trajectory as well as the time to reach maximum pressure within an error of 10% when using a dynamic formulation. On the other hand, the static formulation of the wrinkling factor predicts the time for maximum pressure within a maximum error of 20%.}, keywords = {Ignition, Analytically Reduced Chemistry, LES, Spinning combustion technology}, pdf = {https://cerfacs.fr/wp-content/uploads/2022/06/CFD_Crespo_Comb_flame_AR_CFD_22_61.pdf}}

Di Renzo, M. and Cuenot, B. (2022) A reduced chemical mechanism for the simulation of electrified methane/air flames, Combustion and Flame, 244, pp. 112246, doi:10.1016/j.combustflame.2022.112246

[url] [doi]

@ARTICLE{AR-CFD-22-67, author = {Di Renzo, M. and Cuenot, B. }, title = {A reduced chemical mechanism for the simulation of electrified methane/air flames}, year = {2022}, volume = {244}, pages = {112246}, doi = {10.1016/j.combustflame.2022.112246}, journal = {Combustion and Flame}, url = {https://www.sciencedirect.com/science/article/abs/pii/S0010218022002619}}

Aniello, A., Schuster, D., Werner, P., Boussuge, J. -F., Gatti, M., Mirat, C., Selle, L., Schuller, T., Poinsot, T. and Ruede, U. (2022) Comparison of a finite volume and two Lattice Boltzmann solvers for swirled confined flows, Computers and Fluids, 241, pp. 105463, doi:10.1016/j.compfluid.2022.105463

[doi]

@ARTICLE{AR-CFD-22-56, author = {Aniello, A. and Schuster, D. and Werner, P. and Boussuge, J.-F. and Gatti, M. and Mirat, C. and Selle, L. and Schuller, T. and Poinsot, T. and Ruede, U. }, title = {Comparison of a finite volume and two Lattice Boltzmann solvers for swirled confined flows}, year = {2022}, volume = {241}, pages = {105463}, doi = {10.1016/j.compfluid.2022.105463}, journal = {Computers and Fluids}, abstract = {A finite volume and two Lattice–Boltzmann unsteady, flow solvers using LES (Large Eddy Simulation) were compared in a swirling flow configuration, typical of aeronautical combustion chambers. Numerical results were validated against experimental data collected at EM2C laboratory by comparing pressure losses, mean and RMS velocity profiles on multiple planes and axial velocity spectra. Meshes and the overall numerical setups were individually adjusted for each code to obtain the targeted accuracy before comparing CPU efficiencies. Results confirm that the three LES codes provide high fidelity results, much better than usual RANS especially in terms of RMS data. The analysis of CPU performances shows that LBM (Lattice–Boltzmann Method) solvers are faster than the finite volume solver, even if CPU efficiencies remains of the same order of magnitude. In addition, strong scaling tests from 36 to 900 cores show that the finite volume solver scales more efficiently than the LBM codes, specially when the number of grid points per core is not sufficient.}, keywords = {CPU efficiency, Large Eddy Simulation, LBM and FVM comparison, Swirling flow}}

Peatier, S., Sanderson, B. M., Terray, L. and Roehrig, R. (2022) Investigating Parametric Dependence of Climate Feedbacks in the Atmospheric Component of CNRM-CM6-1, Geophysical Research Letters, 49 (9), pp. e2021GL095084, doi:10.1029/2021GL095084

[doi]

@ARTICLE{AR-CMGC-22-57, author = {Peatier, S. and Sanderson, B.M. and Terray, L. and Roehrig, R. }, title = {Investigating Parametric Dependence of Climate Feedbacks in the Atmospheric Component of CNRM-CM6-1}, year = {2022}, number = {9}, volume = {49}, pages = {e2021GL095084}, doi = {10.1029/2021GL095084}, journal = {Geophysical Research Letters}}

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2 years Postdoc project: Grammar-guided multigrid solver optimization for the Stokes equations

 

2 years Postdoc project: Grammar-guided multigrid solver optimization for the Stokes equations   The solution of...Read more


Hydrodynamic modelling at CERFACS

 

Contact: Sophie Ricci Senior Researcher ricci@cerfacs.fr Objective: The project aims at making use of Earth Observation...Read more

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