Modeling and analytical studies will be carried out for turbulent combustion systems. Included in these studies will be efforts directed at development of better understanding of fundamental mixing processes. This research will be carried out in two basic stages: (1) An analytical study to shed light on the dependency of time evolution of chemical composition as a function of the mixing parameters governing various systems of interest; (2) A model development and implementation effort to apply new ideas in turbulent mixing modeling to full scale combustion systems. In this activity, the turbulent mixing and reaction processes will initially be modeled based on ideas developed in prior formulation of a linear eddy model, the only current model formulation that allows for distinction between the effects of molecular diffusion and turbulent stirring at the smallest turbulent scale of the flow; such a distinction is required for accurate prediction of the small- scale mixing which governs turbulent combustion processes. An advanced formulation which can be used in industrial combustion applications will be pursued. Part of the research project will be devoted to implementation of such models and resulting computer codes on massively parallel computing machines. Energy conservation and environmental protection issues provide a strong impetus for development of cleaner, more efficient combustion processes. Since most combustion occurs in a turbulent environment and it is the turbulent mixing that governs the overall combustor performance in most cases, it is very important that turbulent mixing and combustion be treated in a more comprehensive manner than in the past. As part of this program, models will be applied to realistic combustion chemistries for analysis of energy production and pollutant formation.
