Development of Micromixing Strategies Using Extensional Flow Elements*

Computational fluid dynamics modeling was used to characterize the effect on mixing of the integration of constrictions into a serpentine channel. The constrictions are defined by hyperbolic functions, that seek to maximize the extensional flows experienced by the fluid, while limiting the increase in the pressure drops along the channel. In this new topology, the combination of these flows with the Dean flows formed in the curved sections due to the centrifugal forces experienced by the fluid, results in complex flows that are found to enhance the mixing performance of these systems. Optimization of the mixers with respect to the improvement in the mixing performance relative to simple serpentine designs identifies designs for which the mixing performance exceeds 0.93 (1.00 being the maximum) for a broad range of Reynolds numbers.