Assessment of a Nonlocal Closure Model for Scalar Fields in Reacting Turbulent Flows

Reduced-order models for turbulent reacting flows often use locally calculated parameters to capture the underlying chemical and transport processes, but past work into the effects of turbulent transport on reaction dynamics and vice versa has shown that the consideration of nonlocal effects is essential to accurately predicting mean scalar fields. However, models using theory developed for non-reactive dispersion of scalars and for linear reactions that simply use nonlocal operators have yielded suboptimal results when considering systems of binary reacting scalars. In this work, a two-equation algebraic Reynolds-averaged Navier-Stokes model is developed which is capable of capturing unresolved interactions between multi-component scalar reactions in turbulent flows. This model shows improvement over existing ones in the literature and provides a systematic framework for the incorporation of nonlocality. These effects can be generalized to various source and reaction terms.