Cerfacs Enter the world of high performance ...

The 11 May 2015

PhD Defense: Charlie KOUPPER – Unsteady multi-component simulations dedicated to the impact of the combustion chamber on the turbine of aeronautical gas turbines

Marie LABADENS |  Cerfacs Salle de conference Jean-Claude André |  

Abstract :
Nowadays, engines powering modern and large commercial or military aircraft essentially rely on gas turbine technologies. Since the first prototypes built in the 40’s, the efficiency and specific power of such engines have improved to the point where each individual module reaches efficiency levels so that any new substantial gain can only be the result of a significant effort, cost or a technological breakthrough. An alternative path for improvement arises if one acknowledges that the engine is in the end a fully integrated system where all components interact with each other, modifying each individual component effective operating condition and efficiency compared to their disassembled versions. With the increasing compactness of new engines such interactions are clearly enhanced and the study of the interactions between engine components (sparsely addressed in the past) becomes a substantial source of gains in overall engine performance. In this context, the engine interface that is today the most critical and that is not adequately covered in an isolated component analysis coincides with the region linking the combustion chamber to the turbine. This region of the engine is indeed the most critical and aggressive part of an engine in terms of pressure, temperature and stresses. The objective of this PhD dissertation is to improve the current characterization of the combustor-turbine interface to assess existing design processes at this interface and help increasing the turbine efficiency. To do so, a new nonreactive Combustor Simulator (CS) representative of modern Lean Burn combustion chambers is developed within the framework of the European project FACTOR (FP7). The flow in this module is then investigated by means of an extensive use of Large Eddy Simulations (LES) and experimentally characterized based on a tri-sector version of the module installed at the University of Florence (Italy). Based on the complementary use of this experiment and LES, a comprehensive and exhaustive database is constructed to qualify advanced simulations and exit chamber quantities useful for the design and understanding of the combustor-turbine interface. Advanced diagnostics and validation procedures taking advantage of the rich time-resolved fields are furthermore proposed in an attempt to improve the existing design process whenever dealing with the interface of the combustor / turbine modules. For example, it is shown at this occasion that it is sometimes possible and necessary to go beyond the simple analysis of mean (and RMS) fields to qualify predictions at this interface. To finish and to go beyond the treatment of this interface, a fully integrated simulation of the CS fitted with a pair of high pressure vanes at its exit is produced to complement our understanding. These purely numerical predictions highlight the impact of the vane potential effect as well as the influence of the vane clocking relative to the fuel injection systems for the specific case of this Lean Burn architecture. This last set of LES highlights the difficulty of adequately apprehending the combustor / turbine interface and confirms that it could ultimately be simulated by use of LES if needed.

Keywords : Gas turbine, LES, turbulence, combustor, turbine

Jury

P. BRUEL              Université de Pau et des Pays de l’Adour           Referee
T. VERSTRAETE  Von Karman Institute for Fluid Dynamics            Referee
B. FACCHINI        Università degli Studi di Firenze                          Member
L. HE                    University of Oxford                                              Member
L. JOLY                ISAE Toulouse                                                     Member
G. BONNEAU      Turbomeca Bordes                                              Invited member

L. GICQUEL        Cerfacs                                                                 Advisor
F. DUCHAINE     Cerfacs                                                                  co-advisor

NEWS

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

ALL NEWS