In this work we applied lattice Boltzmann (LB) method to investigate the mixing performance and hydrodynamics inside droplet passing through baffled channels periodically. Specifically, a color-gradient model was employed to simulate micro-droplet motions and a LB algorithm of passive tracer was added to characterize mixing inside droplet without any influence on the macroscopic fluid motions. Our simulation results show that the added baffle in microchannels would force the droplet to deform, which leads to dynamically changing internal recirculation and thus enhancing mixing performance. The internal circulation periodically changes according to the length of the baffle; the local field is much similar to that in straight channels with the same channel width. By comparing the intensity of mixing in the cases with different initial species distributions, we found that coordination between circulation area and heterogamous region of tracer plays an important role in mixing performance because stream trajectories directly distribute the species into lower concentration region. In addition, our results show that the location of baffle is another influencing factor contributing to enhance mixing due to the effect of droplet rotation. Results in this work would be greatly helpful for analyzing the practical process design and constructing the microchannel geometry.

在这项工作中，我们应用了格子Boltzmann（LB）方法来研究定期通过折流板通道的液滴内部的混合性能和流体力学。具体而言，使用颜色渐变模型来模拟微滴运动，并添加了被动示踪剂的LB算法来表征液滴内部的混合，而对宏观流体运动没有任何影响。我们的仿真结果表明，微通道中增加的挡板将迫使液滴变形，从而导致内部循环的动态变化，从而增强混合性能。内部循环根据挡板的长度定期变化；局部场与具有相同沟道宽度的直通道非常相似。通过比较不同物种初始分布情况下的混合强度，我们发现示踪剂的循环面积和杂种区域之间的协调在混合性能中起着重要作用，因为水流轨迹将物种直接分布到较低浓度区域。此外，我们的结果表明，由于液滴旋转的影响，挡板的位置是另一个有助于增强混合的影响因素。这项工作的结果将对分析实际的工艺设计和构建微通道几何形状有很大的帮助。我们的结果表明，由于液滴旋转的影响，挡板的位置是另一个有助于增强混合的影响因素。这项工作的结果将对分析实际的工艺设计和构建微通道几何形状有很大的帮助。我们的结果表明，由于液滴旋转的影响，挡板的位置是另一个有助于增强混合的影响因素。这项工作的结果将对分析实际的工艺设计和构建微通道几何形状有很大的帮助。