Experimental and numerical investigations on micromixing performance of multi-orifice cross-flow jet mixers

Abstract

Multi-orifice cross-flow jet mixers (MOCJMs) are used in various industrial applications due to their excellent mixing efficiency, but few studies have focused on the micromixing performance of MOCJMs. Herein, the flow characteristics and micromixing performance inside the MOCJM were investigated using experiments and computational fluid dynamics (CFD) simulations based on the Villermaux/Dushman system and the finite rate/modified eddy dissipation model (FR/MEDM). The optimal A value was correlated with the characteristic parameters of MOCJMs to develop a CFD calculation method applicable to the study of the micromixing performance of the MOCJMs. Then the micromixing efficiency was evaluated using the segregation index XS, and the effects of operational and geometric parameters such as mixing flow Reynolds number (ReM), flow ratio (RF), total jet area (ST), number of jet orifices (n) and outlet configuration on the micromixing efficiency were investigated. It was found that the intensive turbulent region generated by interactions between jets, as well as between jets and crossflows, facilitated rapid reactions. XS decreased with increasing ReM and decreasing RF. Furthermore, MOCJMs with lower ST, four jet orifices, and the narrower outlet configuration demonstrated a better micromixing efficiency. This study contributes to a deeper understanding of the micromixing performance of MOCJMs and provides valuable guidance for their design, optimization, and industrial application.