In this study we investigate the mixing performances of a modified micromixer which achieves a very good mixing quality that can be compared to other micromixers proposed recently, our idea proposes a modification of the crossing zone to reduce the unit number. The numerical simulations have been carried out at low Reynolds numbers using the CFD Fluent code to solve the 3D momentum equations, continuity equation, and the species transport equations. The elongation of the crossing zone is defined by a parameter called aspect ratio (l/W). A parametric study was realized using five values of aspect ratio (l/W) from 0 to 1 in a wide range of Reynolds numbers: from 0.2 to 80. To analyze the obtained results through the numerical simulations, the mass fraction contours, velocity vectors, velocity profiles, and pressure losses were presented in different cross-sectional planes and positions. The selected geometry (with l/W = 1) has excellent mixing performances where the obtained mixing index exceeds 85.67% for Re = 0.2 and reaches 99.22% for Re = 50, it also has a lower pressure drop compared to other geometries studied recently. Therefore, the selected micromixer shows high mixing performances at low Reynolds numbers, so it can be employed to improve fluid mixing in various microfluidic systems.

在这项研究中，我们研究了改进的微混合器的混合性能，该混合器可实现非常好的混合质量，可与最近提出的其他微混合器相提并论，我们的想法是对交叉区域进行修改以减少单位数量。使用CFD Fluent代码在低雷诺数下进行了数值模拟，以求解3D动量方程，连续性方程和物种迁移方程。交叉区域的伸长率由称为纵横比（l / W）的参数定义。在宽范围的雷诺数范围内（从0.2到80），使用从0到1的五个纵横比（l / W）值来实现参数研究。要通过数值模拟，质量分数等高线，速度矢量分析所得结果，速度曲线，在不同的横截面和位置显示了压力损失。选定的几何形状（l / W = 1）具有出色的混合性能，其中对于Re = 0.2所获得的混合指数超过85.67％，对于Re = 50所达到的混合指数达到99.22％，与最近研究的其他几何形状相比，其压降也更低。因此，所选的微混合器在低雷诺数下显示出高混合性能，因此可用于改善各种微流体系统中的流体混合。