Fundamental and Applied Combustion Dynamics

The interaction of turbulent fluid motion with combustion chemistry has many interesting effects across a wide range of scales. In this talk, we will explore how laser-based measurement techniques can help explain such interactions using two very different examples. Particular emphasis will be placed on ‘high-speed’ laser diagnostics that acquire data with sufficient temporal resolution to capture causality of the targeted phenomena. After a brief introduction to the physics, capabilities, and limitations of the diagnostics, we will attempt to reconcile discrepancies observed between experimental reactant consumptions rate and classical flame sheet theories at high turbulence intensities. This will be done by explicitly tracking fluid elements through 4D experimental data sets. Switching from micro- to macro-scales, we then will explain the physical mechanisms triggering, sustaining, and attenuating thermoacoustic oscillations in an aeronautical gas turbine combustor at flight-relevant conditions. Understanding these mechanisms can lead to improved design and operation of aeronautical engines for reduced environmental impact.