Chemical reactions in turbulent mixing flows

In the course of this research we have conducted investigations of turbulent mixing, chemical reaction, and combustion processes in turbulent, subsonic, and supersonic flows. The program was comprised of several parts: an experimental effort, a theoretical and numerical simulation effort, and a development of instrumentation and diagnostics; an upgrade of flow and combustion facilities; and the development of data-acquisition sub-systems. We have carried out a series of theoretical and experimental studies of turbulent mixing in two well-defined, fundamentally important flow fields: free-shear layers and axisymmetric jets. To elucidate molecular transport effects, experiments and theory have dealt with both reacting and non-reacting flows of liquids and gases in fully-developed turbulent flows. A criterion for fully-developed turbulence was recently developed. The computational studies are, at present, focused at fundamental formulation and implementation issues pertaining to the simulation of both compressible and incompressible flows characterized by strong fronts, such as shock waves and flames. In our diagnostic development efforts we have improved the signal-to-noise ratio of flow images, in both gas- and liquid-phase flows, as well as continued with the development of data-acquisition electronics to meet very high-speed, high-volume data requirements; the acquisition of single, or pairs, of two-dimensional images in rapid succession; and the acquisition of data from arrays of supersonic flow sensors.