Achieving rapid mixing of different liquids in a short distance is important for biochemical applications. Here, a new type of micromixers consisting of double symmetrical V-shaped baffles (MMA and MMB mixers) and double asymmetrical V-shaped baffles (MMC and MMD mixers) is proposed. Numerical simulations are performed to evaluate their mixing performance when the Reynolds number (Re) ranges from 0.1 to 50. Meanwhile, the visualization of vortex formation is conducted to analyze the mixing mechanism. The results show that the mixing efficiency of all mixers approaches 0.8 for all Re at the short distance of 3500 μm. At relatively low Re=0.5, the MMA and MMB perform better than MMC and MMD due to more adequate molecular diffusion; whereas the unbalanced lateral flows and multidirectional vortices in the MMC and MMD induce stronger chaotic convection at high Re=50, leading to a higher performance. Moreover, the disturbance created by the vortex on the mass transfer surface is not only relying on its vorticity but also correlates with the position of vortex/vortex leg. Lastly, all micromixers are fabricated, tested and compared with the simulation results and both of them show a good agreement.

在短距离内实现不同液体的快速混合对于生化应用非常重要。在这里，提出了一种由双对称 V 形挡板（MMA 和 MMB 混合器）和双不对称 V 形挡板（MMC 和 MMD 混合器）组成的新型微混合器。进行数值模拟以评估雷诺数 ( Re ) 范围为 0.1 至 50时的混合性能。同时，进行涡流形成的可视化以分析混合机制。结果表明，所有混合器的混合效率在 3500 μm 的短距离内对所有Re的混合效率接近 0.8 。在相对较低的Re=0.5，由于更充分的分子扩散，MMA和MMB的性能优于MMC和MMD；而 MMC 和 MMD 中的不平衡侧向流和多向涡流在高Re = 50 时引起更强的混沌对流，从而导致更高的性能。此外，涡流在传质面上产生的扰动不仅取决于其涡量，还与涡/涡腿的位置有关。最后，所有的微混合器都经过制造、测试并与模拟结果进行比较，两者都显示出良好的一致性。