Quantifying the Relative Importance of Transport and Reaction Closures in a Canonical Premixed Turbulent Flow Setting

The study of reduced-order models for turbulent reacting flows often does not involve a disentangling of the underlying chemical and transport processes through a decoupling of the momentum and scalar equations. Previous work into the effects of turbulent transport on reaction dynamics and vice versa has shown that it is difficult to find analytic models for the prediction of mean scalar fields even in this simplified context. In this project, fully controlled and characterized homogeneous isotropic turbulence is used as a testbed to study closures involved in the evolution of a premixed reaction. Unresolved interactions inherent to incompressible turbulent flows are characterized across a broad parameter range and algebraic models are considered for closure terms. This analysis provides insight into the relative importance of modeling efforts for the scalar equation, which can be generalized to various heat source and reaction terms that support a propagating reaction front.