Effects of operator nonlocality on closures for multicomponent reactive flows based on dispersion analysis

Abstract

Nonlocal algebraic closure models associated with both unresolved advective transport and nonlinear reaction terms in a Reynolds-averaged Navier-Stokes context are presented in this work. In particular, a system of species subject to binary reactions and transport by advection and diffusion are examined by expanding upon analysis originally developed for binary reactions in the context of Taylor dispersion of scalars. This work extends model forms from weakly-nonlinear extensions of that dispersion theory and the role of nonlocality in the presence of reactions is studied and captured by analytic algebraic expressions. These expressions can be incorporated into an eddy diffusivity matrix that explicitly capture the influence of chemical kinetics on the closure operators. Furthermore, we demonstrate that the model form derived in a laminar context directly translates to an analogous setup in homogeneous isotropic turbulence. We show that this framework improves prediction of mean quantities compared to previous results.