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The 19 September 2017 from 14h00 to 17h00

PhD Defense : César BECERRIL – Simulation of Noise Emitted by a Reactive Flow

6tem9cerfacs |  Cerfacs, Salle de conférence Jean-Claude ANDRÉ  |  

Abstract:

Combustion noise is increasing its relative contribution to aircraft noise, while other sources are being reduced and new low-NOx emission combustion chambers being built. Two mechanisms are responsible for this noise source: direct noise in which acoustic waves are generated by the flame and propagate to the outlet of the aero-engine, and indirect noise, where entropy waves generate noise as they are accelerated and decelerated in the turbine stages. In this work, the analytical models used for the propagation of waves through non-homogeneous flows, including the generation of indirect noise, are revised and extended. In the first part, the quasi-1D case is studied, extending the analytical method to non-zero frequencies and validating the results with numerical methods and experimental data. In the second part, the 2D method for the case of compact turbine blades is studied and validated using numerical simulations of a rotating blade and of a complete turbine stage. Finally, in the third part of this thesis, these models are combined with reactive and compressible Large Eddy Simulations (LES) of combustion chambers to build a hybrid approach, named CHORUS, able to predict combustion noise.

Keywords: Combustion noise, indirect noise, aero-acoustics, analytical methods.

Members of the Jury :

Friedrich BAKE                               DLR, Deutchland                                                     Member

Sébastien DUCRUIX                      CENTRALE SUPELEC, France                              Referee

Aimée MORGANS                          MPERIAL COLLEGE LONDON                              Member

Franck NICOUD                              UNIVERSITE DE MONTPELLIER, FRANCE         Referee

Maxime HUET                                 ONERA, PALAISEAU                                             Advisor

Stéphane MOREAU                        SHERBROOKE UNIVERSITY, CANADA               Co-Advisor

Laurent GICQUEL                           CERFACS, FRANCE                                              ADVISOR

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