Modeling turbulence - Physics or curve fitting

It is noted that the presence of turbulence alters mixing and reaction times in chemically reactive flows. These effects in turn change the heat and mass transfer rates and hence the local and global dynamics of combustion systems. It is sought to describe the fundamental physical processes that must be modeled in order to understand reactive flow turbulence; it is then shown how detailed ab initio modeling of these phenomena can be used to help construct a phenomenological turbulence model for reactive flow. Three different aspects of reactive flow mixing are identified as focal points for the detailed modeling, and a number of important criteria are established which an accurate and consistent subgrid reactive flow mixing phenomenology should satisfy. One possible representation for such a generalized phenomenology is given.