Laminar Fluid Mixing in Micromixers: Description of Pull‐Push Effects

Abstract

A numerical study was performed on laminar mixing of fluids by means of embedded microbarriers against the flow direction in two three-dimensional T-micromixers. Two microchannels with different obstacle arrangements were considered, and the effect of volumetric flow rate Q on two-stream pull-push motion was investigated. With increasing Q and distance of the barriers to the sidewalls K, different vortices and fluid movement patterns develop in the two micromixers. Maximum mass transfer is obtained for the micromixer with smaller K value. With decreasing K, pull-push movement strongly affects fluid merging, and the quality of mixing increases. Moreover, the effect of fluid tortuosity was studied, and a direct relationship between hydrodynamic fluid tortuosity and mass transfer was found.