Three-scalar measurements were made in a turbulent nonpremixed flame (Re=15000) to increase confidence in the two-scalar technique based on simultaneous imaging of Rayleigh scattering and fuel Raman scattering. Nitrogen Raman scattering was employed as an passive conserved scalar and mixture fraction was calculated by two independent approaches. These experiments showed that proper parameterization of mixture fraction-dependent terms appearing in the expression for mixture fraction can reduce deficiencies for lean values of mixture fraction and near stoichiometric. Additionally, the spatial resolution of the optical setup was characterized and determined to be sufficient for resolving scalar dissipation.

Three-scalar measurements were made in a turbulent nonpremixed flame (Re=15000) to increase confidence in the two-scalar technique based on simultaneous imaging of Rayleigh scattering and fuel Raman scattering. Nitrogen Raman scattering was employed as an passive conserved scalar and mixture fraction was calculated by two independent approaches. These experiments showed that proper parameterization of mixture fraction-dependent terms appearing in the expression for mixture fraction can reduce deficiencies for lean values of mixture fraction and near stoichiometric. Additionally, the spatial resolution of the optical setup was characterized and determined to be sufficient for resolving scalar dissipation.

As part of an ongoing research program aimed at developing techniques capable of quantitative imaging of mixture fraction and scalar dissipation in turbulent flames, three-scalar measurements were made in a turbulent nonpremixed flame. The use of nitrogen Raman scattering to detect a passive conserved scalar made it possible to increase confidence in the two-scalar technique based on simultaneous imaging of Rayleigh scattering and fuel Raman scattering. These experiments showed that proper parameterization of mixture fraction-dependent terms appearing in the expression for mixture fraction can improve accuracy for lean values of mixture fraction as well as those near stoichiometric. Additionally, a new experimental technique was investigated which allows the extraction of velocity information from laser-based scalar imaging in turbulent flows. Preliminary results from simultaneous particle-imaging velocimetry (PIV) and optical flow velocimetry showed that this technique has potential for unseeded velocity measurements compatible with the mixture fraction imaging. The optical flow approach was based on extracting velocity vectors from the intensity variations naturally present in inhomogeneous turbulent flow images of a mixing-dependent scalar quantity.

Partial contents: Supercritical droplet behavior; Fundamentals of acoustic instabilities in liquid-propellant rockets; Modeling liquid jet atomization proceses; Liquid-propellant droplets dynamics and combustions in supercritical forced convective environments; Contributions of shear coaxial injectors to liquid rocket motor combustion instabilities; High pressure combustion studies under combustion driven oscillatory flow conditions; Droplet collision on liquid propellant combustion; Combustion and plumes; Development of a collisional radiative emission model for strongly nonequilibrium flows; Energy transfer processes in the production of excited states in reacting rocket flows; modeling nonequilibrium radiation in high altitude plumes; kinetics of plume radiation, and of HEDMs and metallic fuels combustion; Nonsteady combustion mechanisms of advanced solid propellants; Chemical mechanisms at the burning surface. p15