Characterization of high intensity turbulent flows through time resolved particle image velocimetry in a backward facing step combustor
The fundamental understanding of turbulent premixed combustion has taken place as one of the major research topics of interest in industry thanks to advancements in kHz level laser diagnostics such as in Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF). Because of said advancements in this technology researchers and the scientific community are now able to expand their understanding of flame studies at high turbulence conditions to acquire a better understanding, and improve models used in turbine design, scram/ram jets, rocket engines, and emissions control. This surge of new technologies has made this topic a high priority one for The Air Force Office of Scientific Research (AFSOR). While there have been many studies aiming to provide useful data in this research field, there are still many uncertainties associated with the fundamentals of turbulent pre-mixed combustion, especially at the conditions investigated in this study (ReT>>1, Da≥1, Ka>1, u ,/SL>>1, δL/η>1). As of today designers rely on the design-test-modify method, which is not only time consuming but also expensive. It is because of this that the research community is searching for a reliable and effective numerical model in order to design next generation combustors. The models used in this application need a detailed experimental analysis of the fundamentals of turbulent flame structure and a wide range of experimental data in order to be valid the design models, but few studies at these flame conditions are available making this the main drive for this work. The main goal of this study is to establish the limits and capabilities to reach different flame regime boundaries under Mach Number (M)>.3 and (Re t) > 103 of CH4 – air premixed flames, of a backward facing step combustor. This study provides the global characteristics of a backward facing step high intensity turbulent flows through high speed flow visualization. It also determines the capability of the experimental setup to reach the thickened flame regime, while generating the components of the flow’s turbulent intensity and turbulent kinetic energy.
de la Torre, Martin Alexandro, "Characterization of high intensity turbulent flows through time resolved particle image velocimetry in a backward facing step combustor" (2016). ETD Collection for University of Texas, El Paso. AAI10250693.