Cerfacs Enter the world of high performance ...

The 28 April 2016 at 14h00

PhD Defense: Thomas JARAVEL – Prediction of pollutants in gas turbines using Large Eddy Simulation




Stringent regulations of pollutant emissions now apply to new-generation combustion devices. To achieve low nitrogen oxides (NOx) and carbon monoxide (CO) emissions simultaneously, a complex optimization process is required in the development of new concepts for engines. Already efficient for the prediction of turbulent combustion, Large Eddy Simulation (LES) is also a promising tool to better understand the processes of pollutant formation in gas turbine conditions and to provide their quantitative prediction at the design stage. In this work, a new methodology for the prediction with LES of NOx and CO in realistic industrial configurations is developed. It is based on a new strategy for the description of chemistry, using Analytically Reduced Chemistry (ARC) combined with the Thickened Flame model (TFLES). An ARC with accurate CO and NO prediction is derived, validated on canonical laminar flames and implemented in the LES solver. The accuracy of this approach is demonstrated with a highly resolved simulation of the academic turbulent Sandia D flame, for which excellent prediction of NO and CO is obtained. The methodology is then applied to two industrial configurations. The first one is the SGT-100, a lean partially-premixed gas turbine model combustor studied experimentally at DLR. LES of this configuration highlights the chemical processes of pollutant formation and provides qualitative and quantitative understanding of the impact of the operating conditions. The second target configuration corresponds to a mono-sector prototype of an ultra-low NOx, staged multipoint injection aeronautical combustor developed in the framework of the LEMCOTEC European project and studied experimentally at ONERA. An ARC for the combustion of a representative jet fuel surrogate is derived and used in the LES of the combustor with an Eulerian formalism to describe the liquid dispersed phase. Results show the excellent performances of the ARC, for both the flame characteristics and the prediction of pollutants.

Keywords :Reduced Chemistry, Gas turbines, Pollutant prediction, Large Eddy Simulation, Turbulent combustion

Jury  :

Prof. H. Pitsch                                   RWTH Aachen University                   Referee
D. Veynante                                      CNRS                                                  Referee
F. Battin-Leclerc                                CNRS                                                  Member
O. Colin                                             IFPEN                                                  Member
P. Pepiot-Desjardins                         Cornell University                                 Member
A. Cayre                                            SNECMA                                             Invited
S. Richard                                         TURBOMECA                                      Invited
B. Cuenot                                          CERFACS                                           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