Host Institution: Centrale Supélec (France)
Phone: +33 1 4113
The main research area which I will be focused on is related to LEAN PREMIXED combustion, and specifically aimed at analyzing the main physical mechanisms responsible of some undesired dynamic phenomena like the sudden flashback of the flame in the injector, the blow-off of the combustion or the thermo-acoustic instabilities that make this combustion mode still not efficient at the industrial level, despite its benefits in terms of pollutant emissions.
The objective of the work is to investigate the dynamic response of a limited number of reference flames where these phenomena will be investigated by synchronized diagnostics with the acoustic pulsation. The flow will be characterized by means of special techniques like Laser Doppler velocimetry (LDV) and Laser Induced Phosphorescence (LIP). Post-processing of the data will reveal the main parameters controlling the flame response and will be used to validate numerical simulations. My biggest aim is to understand the chemical and physical mechanisms that rule these phenomena, in order to be able to predict and thus to control them, and after that to give my best help in finding the best way to numerically simulate them.
Objectives. Stabilization of flames by imparting swirl to the flow allows operating the combustor in a lean premixed combustion mode, which is an efficient way to reduce pollutant emissions in gas turbines and industrial boilers. In this combustion mode, flames are however very sensitive to dynamic phenomena leading to sudden flashback of the flame in the injector, blow-off of the combustion or thermo-acoustic instabilities with undesirable large self-sustained oscillations. Determining the flame response to controlled flow pulsations allows analyzing the main physical mechanisms responsible of these dynamic phenomena. The objective of the work is to define a limited number of reference flames where these phenomena will be investigated by synchronized diagnostics with the acoustic pulsation. These data should allow a detailed description of the flame, flow and acoustic interactions taking place in the different configurations investigated and provide the necessary data for detailed numerical simulations.
Expected results. In this project the dynamic response of a series of reference flames will be investigated. Laser Doppler velocimetry and Laser Induced Phosphorescence will be used to characterize the flow and thermal boundary conditions. Particle Imaging Velocimetry and OH Planar Laser Induced Fluorescence will be used to characterize the response of the flow and flame to acoustic forcing. Post-processing of these data will reveal the main parameters controlling the flame response and will be used to validate simulations in close collaboration. The data are explored in cooperation with the project partners for validation and simulations.
Planned secondment. DE-TUD (6-8 months). Data post processing and involvement to validation of numerical simulations.