Section: Partnerships and Cooperations

National Initiatives

ANEMOS: Advanced Numeric for ELMs, Modeling and Optimized Schemes

Participants : Xavier Lacoste, François Pellegrini, Pierre Ramet [Corresponding member] .

Grant: ANR-11-MN

Dates: 2011 – 2015

Partners: CEA IRFM, JAD INRIA, Maison de la Simulation.

Overview:

The main goal of the project is to make a significant progress in understanding of largely unknown at present physics of active control methods of plasma edge MHD instabilities Edge Localized Modes (ELMs) which represent particular danger with respect to heat and particle loads for Plasma Facing Components (PFC) in ITER. Project is focused in particular on the numerical modeling study of such ELM control methods as Resonant Magnetic Perturbations (RMPs) and pellet ELM pacing both foreseen in ITER. The goals of the project are to improve understanding of the related physics and propose possible new strategies to improve effectiveness of ELM control techniques. The tool for the non-linear MHD modeling (code JOREK ) will be largely developed within the present project to include corresponding new physical models in conjunction with new developments in mathematics and computer science strategy in order to progress in urgently needed solutions for ITER.

This proposal is the logic but even more challenging continuation of the previous ANR project ASTER (2006-2010). These works are involved in the large-scale initiative supported by INRIA on magnetic fusion and also take a place in a new LABEX VENUS proposal submitted in October 2011.

Web: http://aster.gforge.inria.fr/

PETALH: Preconditioning scientific applications on pETascALe Heterogeneuous machines

Participants : Astrid Casadei, François Pellegrini [Corresponding member] , Pierre Ramet.

Grant: ANR Cosinus 2010

Dates: 2011–2012

Partners: INRIA Saclay-Ile de France (leader of the project), Paris 6, IFP (Rueil-Malmaison), CEA Saclay.

Overview: In this collaborative effort, we propose to develop parallel preconditioning techniques for the emergent hierarchical models of clusters of multi-core processors, as used for example in future petascale machines. The preconditioning techniques are based on recent progress obtained in combining the well known incomplete LU (ILU) factorization with tangential filtering.

The track we are following in order to contribute to this goal is to investigate improved graph ordering techniques that would privilege the diagonal dominance of the matrices corresponding to the subdomains of the Schur complement. It amounts to integrating numerical values into the adjacency graph of the matrices, so that the importance of off-diagonal terms is taken into account when computing graph separators. The core of this work is planned to take place at the beginning of next year.

This project is a continuation of PETAL project that was funded by ANR Cosinus 2008 call.

Web: http://petal.saclay.inria.fr/

UFO: Uncertainty quantification For compressible fluid dynamics and Optimisation.

Participants : Rémi Abgrall, Pietro Marco Congedo.

Grant: ANR MN 2011

Dates: 2011-2014

Partners: INRIA Bordeaux Sud-Ouest (leader), ENSAM Paris Tech, INPG, ONERA, Phimeca.

Overview We are interested in the simulation and the optimisaton of flows with uncertainties on the data and/or the models. Only non intrusive methods are considered in this project in order to re-use easily existing CFD codes, in particular the project members'. We concentrate on the uncertainties occuring in turbulence models for external aerodynamics and those occuring in thermodynamics models for organic fluids as those use in ORC machines. The number of uncertainties can be arbitrary, so we aim at developing methods that can handle as many uncertainties as possible, relying on good algorithms and massive parallelisation. Another aim is also to be able to use experimental data to calibrate pdf via Bayesian techniques. Epistemic uncertainties for turbulence modeling is also a important topic for the project, for which a theoretical framework need to be established.