Soutenance de thèse : Dario MAESTRO » Large Eddy Simulations of the interactions between flames and thermal phenomena: application to wall heat transfer and combustion control »
nteractions between flames and thermal phenomena are the guiding thread of this work. Flames produce heat indeed, but can also be affected by it. Large Eddy Simulations (LES) are used here to investigate these interactions, with a focus on two main topics: wall heat transfer and combustion control. In a first part, wall heat transfer in a rocket engine sub-scale CH4/O2 burner is studied. In the context of launchers re-usability and cost reduction, which are major challenges, new propellant combinations are considered and wall heat fluxes have to be precisely predicted. The aim of this work is to evaluate LES needs and performances to simulate this kind of configuration and provide a computational methodology permitting to simulate various configurations. Numerical results are compared to experimental data provided by the Technische Universität München (Germany). In a second part, combustion control by means of Nanosecond Repetitively Pulsed (NRP) plasma discharges is studied. Modern gas turbine systems use indeed lean combustion with the aim of reducing fuel consumption and pollutant emissions. Lean flames are however known to be prone to instabilities and combustion control can play a major role in this domain. A phenomenological model which considers the plasma discharges as a heat source is developed and applied to a swirl-stabilized CH4/Air premixed lean burner. LES are performed in order to evaluate the effects of the NRP discharges on the flame. Numerical results are compared with experimental observations made at the King Abdulla University of Science and Technology (Saudi Arabia).
Pascal BRUEL Univ. de Pau et des Pays de l'Adour, France Referee
Benoît FIORINA CentraleSupelec, France Referee
Oskar HAIDN Technische Universität München, Allemagne Member
Deanna LACOSTE KAUST, Arabie Saoudite Member
Thierry POINSOT, IMFT Toulouse Advisor
Bénédicte CUENOT, CERFACS Toulouse Co Advisor