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.

各种混合过程处理低雷诺数下的粘性流体的混合。当使用高粘度或易碎流体时，一些新兴趋势依赖于使用主动或被动微结构来实现此任务。然而，由于达到期望结果所需的长停留时间，这种混合器的紧凑性仍然是主要的挑战。分离重组（SAR）混合器是一种有前途的解决方案，因为它们依靠多层工艺在浓度分布图上进行一系列的贝克变换。

当前的工作是一个数值研究，描述了SAR混合器新拓扑的流体动力和混合性能。该混合器的特征在于双重分离和重组，旨在在较短的距离内增加混合物的均一性。为此，使用有限元求解器来计算蠕变流态中粘性流体的压降，摩擦系数，浓度分布和偏析比例。将结果与公开文献中的两种常用SAR混频器进行了比较。研究结果表明，新提出的混合器在较低的能耗要求下具有更好的混合质量，表现出优异的性能。