Mechanisms of lobed jet mixing: Comparison of bilinear, rectangular, and circular lobed mixers

Abstract

In this study, bilinear lobed mixers (BLMs), rectangular lobed mixers (RLMs), and circular lobed mixers (CLMs), with two sectional area ratios of the bypass channel to the core channel, were configured while maintaining the same lobe angle, lobe height, lobed nozzle length, mixing duct length, and core sectional area. Using three-dimensional steady Reynolds-averaged Navier–Stokes equations and the SST k–ω turbulence model, numerical simulations of jet mixing in these lobed mixers at three velocity ratios of the bypass stream to the core stream were performed. The jet mixing characteristics and performances of the three types of lobed mixers were analyzed. Through a comprehensive and in-depth analysis of the jet-mixing flow fields of the three types of lobed mixers, more universal mechanisms of lobed jet mixing were revealed. Systematic and meaningful conclusions were drawn from four aspects: the formation and evolution mechanisms of the cross flow, longitudinal vortices, heat and mass convection, and orthogonal vortex strip. The findings from this study hold significant implications for the development of lobed mixers and exploration of lobed jet-mixing mechanisms.