Mixing Evaluation of a Passive Scaled-Up Serpentine Micromixer With Slanted Grooves
Mixing Evaluation of a Passive Scaled-Up Serpentine Micromixer With Slanted Grooves
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DOI：
10.1115/1.4024146
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发表时间：
2013-08-01
影响因子：
2
通讯作者：
Hassan, Ibrahim
中科院分区：
文献类型：
--
作者：
Cook, Kristina J.;Fan, YanFeng;Hassan, Ibrahim
提出了一种基于流体旋转的新型被动式放大微混合器，并在雷诺数为0.5 ~ 100的范围内进行了实验和数值模拟。流动可视化是用来定性评估流动模式，而诱导荧光是用来量化的物种分布在五个位置沿着通道长度。两种单独的流体通过Y形入口供应到测试部分。流体进入具有四个半圆形部分的曲折通道，每个半圆形部分的底部表面上排列有九个倾斜的凹槽。主要混合通道为3 mm宽和0.75 mm深，总长度为155.8 mm。数值模拟确认在所有研究的雷诺数旋转，旋转的强度随着雷诺数的增加而增加。沟槽被用来促进螺旋流动，而蛇形通道结构导致在Re >= 50（Dean数>= 18.25）处形成Dean涡，其中动量具有更显著的影响。混合度呈先减小后增大的趋势，在Re = 5处出现拐点，标志着从扩散主导向平流主导的转变。界面表面积的增加归功于对流主导制度中的混合改善，而高停留时间允许在扩散主导制度中的显着的质量扩散。在高雷诺数和低雷诺数下都实现了良好的混合，在Re = 100时最大混合指数为0.90。
A novel, passive, scaled-up micromixer based on fluid rotation is proposed and evaluated experimentally and numerically over Reynolds numbers ranging from 0.5 to 100. Flow visualization is employed to qualitatively assess flow patterns, while induced fluorescence is used to quantify species distribution at five locations along the channel length. Two individual fluids are supplied to the test section via a Y-inlet. The fluid enters a meandering channel with four semicircular portions, each of which is lined with nine slanted grooves at the bottom surface. The main mixing channel is 3 mm wide and 0.75 mm deep, with a total length of 155.8 mm. Numerical simulations confirm rotation at all investigated Reynolds numbers, and the strength of rotation increases with increasing Reynolds number. Grooves are employed to promote helical flow, while the serpentine channel structure results in the formation of Dean vortices at Re >= 50 (Dean number >= 18.25), where momentum has a more significant effect. A decreasing-increasing trend in the degree of mixing was noted, with an inflection point at Re = 5, marking the transition from diffusion dominance to advection dominance. The increase in interfacial surface area is credited with the improved mixing in the advection-dominant regime, while high residence time allowed for significant mass diffusion in the diffusion-dominant regime. Good mixing was achieved at both high and low Reynolds numbers, with a maximum mixing index of 0.90 at Re = 100.