Fully Resolved Modelling and Simulation of Micromixing in Confined Impinging Jets

Abstract Confined Impinging Jets (CIJs) are fast mixing meso sized devices for fast reaction applications, where two opposed jets contact the reactants that are mixed by chaotic flow patterns in very short times. Fully resolved CFD chemical reaction in CIJs is out of reach for engineering practice since on the order of 10 11 computational cells would be required. This paper presents a theoretical methodology to describe micromixing in CIJs using a lamellar model that considers the dynamics of striation thinning and diffusion at the interface of the mixing fluids. A lamellar micromixing (LM) model based on mixing evolution functions was applied to simulate chemical reactions. The evolution of mixing scales in CIJs was also studied from fully-resolved CFD simulations that validate the mixing scales predicted from theoretical models. This LM model completely describes the experimental results, and it is thus directly applicable to the design of CIJs technology for chemical processes.