This study proposes a new design of milli- or micro-mixers based on the split-intersect-recombine principle. The vascular flow topology mimics the respiratory or circulatory architectures existing in nature, including tree-like bifurcated networks and meshed flow circuit. Special focus is given to the enhancement of mixing performance by fluid collisions and flow deviations at the intersections of the meshed circuit. To do that, an optical tracer is added in one of the fluids to be mixed and its progression is monitored and recorded by a high-definition CCD camera. The mixing efficiency of the meshed circuit is then characterized by the evolution of the tracer's local concentration profiles based on the Beer-Lambert absorption. Experimental results obtained show that compared to straight channels, the mixing performance can be improved by about 20% owing to the numerous flow intersections in the meshed circuit. Moreover, the viscosity difference between two fluids to be mixed has a positive effect on the mixing performance by augmenting the chance of flow deviation from one stream into another at the crossroads. An optimum performance can be noticed in the form of a plateau of the estimated shear stress.

这项研究提出了一种新的基于混合相交的原理的微型或微型混合器设计。血管流动拓扑模仿了自然界中存在的呼吸或循环结构，包括树状分叉网络和网状流动回路。特别关注的是通过在网状回路的相交处发生的流体碰撞和流量偏差来增强混合性能。为此，在要混合的一种流体中添加了光学示踪剂，并通过高清CCD摄像机监视和记录其进程。然后通过基于比尔-朗伯吸收的示踪剂局部浓度分布图的演变来表征网状回路的混合效率。获得的实验结果表明，与直通道相比，由于网状回路中的许多流动交叉点，混合性能可提高约20％。而且，两种待混合的流体之间的粘度差通过增加在十字路口处从一种流向另一种流的流动偏差的机会而对混合性能产生积极影响。可以以估计的剪切应力的平稳状态的形式注意到最佳性能。