具有多样性混合单元的分离重组微混合器的优化设计与数值分析

Optimized Design and Numerical Analysis of a Split and Recombination Micromixer with Diverse Mixing Units

摘要: 分离重组(SAR)技术是增强微混合器混合效率的有效方法之一，该技术是利用混合单元将流体不断地分离再重组来达到混合目的。目前，大量的混合单元被提出。然而，这些单元的组合对混合的影响尚未被研究。因此，本文基于多样性混合单元，提出一种具有高混合效率的分离重组微混合器。采用菱形、圆形、方形三种差异性结构，这些结构两两组合出九种混合单元，再将这些混合单元分别放入带有三个混合区域的微混合器模型，并通过数值仿真和试验方法分析不同组合下的混合效率。仿真结果表明，菱形结构对微混合器的混合性能提升最大，圆形最弱，带有菱形和方形结构的分离重组微混合器(YOSAR)组合最优。随着雷诺数的增加，YOSAR内流体的混沌平流和迪安流效应加剧，混合效率增加。在雷诺数为100时，YOSAR混合效率达到99%，接近于完全混合。同时，实验结果和仿真结果具有一致性。

Abstract: The split and recombination (SAR) technique is one of the effective methods to enhance the mixing efficiency of a micromixer. It utilizes mixing units to continuously separate and then reorganize flu-ids for mixing purposes. Although numerous mixing units have been proposed at present, the com-bined effect of these units on mixing has not been investigated. Hence, this article proposes a sepa-ration and recombination micromixer with high mixing efficiency based on diverse mixing units. Three differentiated structures, square, circle, and rhombus, are utilized and combined in pairs, resulting in nine different mixing units. These units are then integrated into a micromixer model with three mixing regions. The mixing efficiency of different combinations is analyzed using numer-ical simulation and experimental methods. The simulation results reveal that the rhombic struc-ture enhances the mixing performance of the micromixer the most, while the circular structure is the weakest. The combination of the rhombic and square structures (YOSAR) demonstrates the op-timum performance. As the Reynolds number increases, the chaotic advection and Dean flow effects intensify within the YOSAR, leading to improved mixing efficiency. At a Reynolds number of 100, the YOSAR mixing efficiency reaches 99%, approaching complete mixing. Meanwhile, the experi-mental and simulation results are consistent.