CFD simulation of creeping flows in a novel split-and-recombine multifunctional reactor

Abstract

Various mixing processes deal with the blending of viscous fluids at low Reynolds numbers. Some of the emerging trends rely on the use of either active or passive microstructures to achieve this task when highly viscous or fragile fluids are employed. The compactness of such mixers remains, however, a major challenge due to the long residence times required to achieve the desired outcome. Split-and-Recombine (SAR) mixers are a promising solution since they rely on a multi-lamination process to perform a series of baker’s transforms on the concentration profile.The current work is a numerical study that describes the hydrodynamic and mixing performance of a new topology of SAR mixers. This mixer is characterized by a double separation and recombination aimed at increasing the mixture homogeneity in a shorter distance. For this purpose, a finite element solver is used to compute the pressure drop, friction factor, concentration profile, and segregation scales for a viscous fluid in the creeping flow regime. The results are compared against two commonly used SAR mixers in the open literature. The findings show that the newly proposed mixer exhibits a superior performance through a better mixing quality at a lower energy consumption requirement.