Characterization of the Reacting Jet of a High-Pressure Axially Staged Combustor

Emissions, flame behavior, and flow-field characteristics of a high-pressure reacting jet-in-crossflow are experimentally studied at industry-relevant conditions. An experimental facility consisting of a headend burner, optically accessible test section, and converging exit nozzle is designed, manufactured, and operated over a wide range of conditions for the study. The axial stage consists of an injector that can be modified into three configurations: fully premixed, partially premixed, and non-premixed. Particle image velocimetry (PIV) is used to obtain flow-field dynamics, high-speed CH* chemiluminescence is leveraged to analyze flame characteristics, and emission measurements are made at the exit of the facility to quantify nitrogen oxides (NOx), and carbon monoxide (CO) emissions. These measurement techniques provide insight into flame-flow field interaction, the effects of injector geometry on flame liftoff and stabilization, jet trajectories in the presence of heat release, and how flame stabilization mechanisms affect emissions. The results show for a non-premixed configuration, the flame is lifted further downstream and burns at its core compared to the fully premixed configuration. The results also demonstrate these highly lifted flames provide a significant improvement in NOx formation of the axial stage. For conditions where the flame ignites near the jet exit, the jet centerline is pushed further into the crossflow compared to jets where the flame is lifted further downstream. A jet trajectory correlation that accounts for pressure and heat release is proposed