Cerfacs Enter the world of high performance ...

The 30 June 2017 at 14h00

PhD Defense: Anne FELDEN – Development of Analytically Reduced Chemistries (ARC) and applications in Large Eddy Simulations (LES) of turbulent combustion

Marie LABADENS |  Cerfacs, Salle de conférence Jean-Claude ANDRÉ |  


Recent implementation of emission control regulations has resulted in a considerable demand from industry to improve the efficiency while minimizing the consumption and pollutant emissions of the next generation of aero-engine combustors. Those phenomena are shown to strongly depend upon the underlying complex chemical pathways and their interaction with turbulence. Large Eddy Simulation (LES) is an attractive tool to address those issues with high accuracy at a reasonable computing cost. However, the computation of accurate combustion chemistry remains a challenge. Indeed, combustion proceeds through complex and highly non-linear processes that involve up to hundreds of different chemical compounds, which significantly increases the computational time and often induces stiffness in the resolved equations. As a mean to circumvent these drawbacks while retaining the necessary kinetics for the prediction of pollutants, Analytically Reduced Chemistry (ARC) has recently received high interest in the Computational Fluid Dynamics (CFD) community. ARC is a strategy for the description of combustion chemistry where only the most important species and reactions are retained, in a “physically-oriented way”. ARC is on the verge of becoming affordable at a design stage, thanks to the continuously increasing available computational resources. The goal of the present work is twofold. A first objective is to test and validate efficient techniques and tools by which detailed chemistries are reduced to an LES-compliant format. To do so, the multi-step reduction tool YARC is selected and employed to derive and validate a series of ARC specifically designed to retrieve correct flame structures. A second objective is to investigate the overall feasibility and benefits of using ARC, combined to the Thickened Flame model (DTFLES), in performing LES of configurations of increasing complexity. The first configuration is a sooting swirl-stabilized non-premixed aero-engine combustor experimentally studied at DLR, burning ethylene. LES of this configuration is performed with the AVBP solver, in which ARC has been implemented. By comparison with global chemistry and tabulated chemistry, results highlight the importance of accurately capturing the flow-flame interactions for a good prediction of pollutants and soot. The second configuration is a swirled two-phase flow burner featuring a lean direct injection system and burning Jet-A2. A novel methodology to real fuel modeling (HyChem approach) is employed, which allows subsequent ARC derivation. The excellent results in comparison with measurements constitute an additional validation of the methodology, and provide valuable qualitative and quantitative insights on the flame-spray interactions and on the pollutant formation (NOx) mechanisms in complex flame configurations.


Combustion chemistry, Reduced chemistry, Turbulent combustion, Gas turbines, LES, Pollutants


Nasser DARABIHA     Research Director CNRS, EM2C             Referee

Pascale DOMINGO     Research Director CNRS, CORIA            Referee

Frédéric GRISCH        Professor, INSA de ROUEN, CORIA        Member

Perrine PEPIOT          Assistant Professor, Cornell University      Member

Hai WANG                   Professor, Stanford University                   Member

Stéphane RICHARD    Dr. Engineer, SAFRAN HE                       Invited member

Bénédicte CUENOT    Senior Researcher, HDR, CERFACS       Advisor

Eleonore RIBER          Senior Researcher, CERFACS                 Co Advisor


Thierry Poinsot officially entered the French Academy of Sciences

CERFACS |  8 November 2021

Thierry Poinsot officially entered the French Academy of Sciences on October 12. See presentation here :Read more

The AVBP code from CERFACS at the heart of for PRACE projects from the 23rd call

CERFACS |  30 September 2021

Cerfacs is involved in three PRACE projects of the 23rd call for which hour allocation runs from 01/10/2021 to 30/09/2022. Researchers from ECL/LMFA UMR5509 (Ecole Centrale de Lyon) and IMFT (UMR 5502) laboratories have earned projects entirely based on the use of the LES solver developed by Cerfacs AVBP and involve the support of experts from the CFD and COOP teams underling the importance and effectiveness of collaborations between French labs and Cerfacs. Alexis Giauque from ECL/LMFA UMR5509 (Ecole Centrale de Lyon) has obtained not only one but two PRACE projects! The first project LESFAN (RA0101, 30 000 000 CPU hours on Irene/Rome TGCC) is based on the use of AVBP in the turbomachinery version to study the generation of noise by a fan of a real airplane engine. The second, PRACE-EDGES (RA0101, 40 000 000 CPU hours on Irene/Rome TGCC) focuses on LES modeling of dens gas in complex geometries. To do so, the LMFA Team has developed advanced thermodynamic closures in AVBP allowing the direct simulation of such flows. Laurent Selle from IMFT (UMR 5502) has received CPU hours for the GASTON project (RA0061, 30 000 000 CPU hours on Marenostrum BSC) which aims to study the structure of hydrogen flames in porous materials. For this, IMFT and Cerfacs will perform coupled simulations considering the reactive flow with AVBP as well as the conduction in the porous medium with AVTP which is known to play an central role in the flame stabilization process. Carlos Perez Arroyo from IMFT (UMR 5502) received 16 Mh CPU hours on Joliot-Curie Skylake partition to support his project WONDER.Read more