Dispersion, Mixing, and Combustion in Uniform- and Variable- Density Air-breathing High-speed Propulsion Flows

This is a summary of significant accomplishments in investigations on the dispersion, mixing, and combustion in uniformand variable-density air-breathing high-speed propulsion flows related to scramjet propulsion. In experimental work, progress made in the development of testsection modifications allowed inclined-jet injection in supersonic flow to be studied with and without chemical reactions and heat release. Work on hydrocarbon flames was completed and published, and preliminary investigations on high-pressure effects were conducted. Large-eddy simulations (LES) were performed on chemically reacting flows in complex geometries, achieving both grid convergence and agreement with experiment. The same computational framework was successfully applied to simulations of inclined-jet injection into a supersonic Mach 3.6 stream. A model for an ethylene-fueled scramjet was developed to facilitate parametric studies of ignition delays in flight-relevant environments. Accomplishments in diagnostic developments enabled many of the experiments and included high framing-rate schlieren digitalimaging technologies, two-dimensional temperature-field measurement technologies, advances in data processing and visualization, and advances in multi-component computer control of experiments.