Direct Numerical Simulation of Eddy Diffusivity in a Plane Jet with a second-order reaction

Turbulent flows with chemical reactions can be seen in various fields. Therefore, it is important to establish numerical methods to predict turbulent reactive flows. Reynolds-averaged approach is often used for predictions of reactive flows. In this approach, Reynolds-averaged scalar transport equations are solved by using models for a turbulent mass flux and an averaged production rate by chemical reactions. Here, ui and  are fluctuation components of i direction velocity (Ui) and concentration of species  (), respectively, and <*> denotes an ensemble average of variable *. One of the simplest models for is a gradient diffusion model [1], in which is given by