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The 25 June 2019 at 14h00

PhD defense : Bastien ROCHETTE – “Modelisation and simulation of two-phase flow turbulent combustion in aeronautical engines

auguste |  Cerfacs, Toulouse (France) salle de conférences J.-C. André

Abstract :

Nowadays, more than 80% of the energy consumed on Earth is produced by burning fossil fuels. Alternative solutions to combustion are being developed but the specific constraints related to air transport do not make it possible to currently power engines without introducing a technological breakthrough. These findings explain the research activity to improve the knowledge and the control of combustion processes to design cleaner, and more efficient aeronautical engines. In this framework, Large Eddy Simulations (LES) have become a powerful tool to better understand combustion processes and pollutant emissions. This PhD thesis is part of this context and focuses on the models and numerical strategies to simulate with more accuracy turbulent gaseous and two-phase reacting flows in the combustion chamber of aeronautical engines.
First, a generic and self-adapting method for flame front detection and thickening has been developed for the TFLES model, and validated on several academic configurations of increasing complexity. This generic approach is then evaluated in the LES of a laboratory-scale burner and compared to the classical thickening method. Results show a more accurate thickening in post-flame regions.
Second, from the analysis of 1-D homogeneous laminar spray flames where the dispersed phase has a relative velocity compared to the carrier phase, two analytical formulations for the spray flame propagation speed have been proposed and validated. The agreement between the overall trend of both the measured/estimated spray flame speeds demonstrates that the model and its parameters correctly take into account the main physical mechanisms controlling laminar spray flames.
Finally, the state-of-the-art TFLES models were tested on complex turbulent gaseous and two-phase reacting configurations. The pros and cons of these models were investigated to contribute to the understanding of the mechanisms related to turbulent combustion, and to propose a LES modeling strategy to improve the fidelity of reactive simulations.

Jury :

Ronan VICQUELIN       Laboratoire EM2C – CNRS, Gif-sur-Yvette                Referee

Fabien HALTER            Université d'Orléans                                                   Referee

Denis VEYNANTE        Laboratoire EM2C – CNRS, Gif-sur-Yvette                 Member

Frédéric GRISCH         CORIA Rouen                                                             Member

Stéphane RICHARD     SHE SAFRAN Bordes                                                Industrial thesis Supervisor

Bénédicte CUENOT     CERFACS                                                                   Member

Thierry POINSOT         IMFT-CNRS  Toulouse                                                Advisor

Olivier VERMOREL      CERFACS                                                                   Co-advisor


67 climate modelling groups use OASIS3-MCT to assemble more than 80 coupled applications

superadmin |  10 September 2019

OASIS3-MCT is a coupler of codes developed at Cerfacs and used around the world, mainly for climate modelling applications. Our last survey confirms that OASIS3-MCT is used by 67 modelling groups to assemble more than 80 different coupled applications over the 5 continents. These applications include global or regional configurations of ocean and atmosphere models but also sea ice, sea level, wave, ocean biogeochemistry, land, vegetation, river routing, hydrological and atmospheric chemistry models. OASIS3-MCT is used in 5 of the 7 European Earth System Models participating to the 6th Coupled Model Intercomparison Project (CMIP6) that produces the climate simulations forming the basis of the next report of the Intergovernmental Panel on Climate Change (IPCC)”Read more

Sparse Days Meeting 2019 at Cerfacs, Toulouse

Brigitte Yzel |  12 May 2019

The annual Sparse Days meeting will be held at CERFACS in Toulouse on 11th and 12th July 2019. Registration for the Sparse Days is free but we ask people who are coming to register as soon as possible although the deadline is June 14th. Please complete the registration form (deadline : June 14th) indicating whether you want to give a talk and whether you wish to attend the conference dinner. Although an emphasis will be on parallel aspects, any talk that has an association with sparsity is welcome.Read more