Role of local geometry on droplet formation in axisymmetric microfluidics
Role of local geometry on droplet formation in axisymmetric microfluidics
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轴对称微流体中局部几何形状对液滴形成的作用
DOI：
10.1016/j.ces.2017.01.022
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发表时间：
2017-05
影响因子：
4.7
通讯作者：
Yongping Chen
中科院分区：
文献类型：
--
作者：
Liangyu Wu;Xiangdong Liu;Yuanjin Zhao;Yongping Chen
为了研究轴对称微流控系统中液滴形成的动力学行为，建立了并流聚焦微流控系统中液滴形成的非定常模型，并对其进行了数值分析。毛细管数和局部几何形状的液滴形成制度，液滴尺寸和单分散性以及液滴生成频率的影响进行了检查和分析。一旦确定，液滴形成状态图被提供以定量地描述在轴对称微流体中滴下、滴下-喷射过渡和喷射的相应状态，这取决于毛细管数和孔口半径。结果表明，聚焦孔的存在产生了强烈的流体动力学聚焦效应，使流动聚焦微流体中的液滴形成行为偏离了同向流动。流聚焦微流控系统中滴注-喷射过渡区发生在较小的毛细管数下，且产生的液滴比同向流系统中的液滴小，粒径分布更宽，频率更高。有趣的是，在流动聚焦微流体的液滴形成是显着影响的孔口半径，而它是不敏感的孔口长度。此外，当孔半径足够小或毛细管数大于0.3时，仅观察到喷射状态。随着孔半径的增大，滴注-喷射过渡区和滴注区的毛细数区域变大。
An unsteady model of droplet formation in co-flow and flow-focusing microfluidics is developed and numerically analyzed to investigate the dynamic behaviors of droplet formation in axisymmetric microfluidics with a focus on the role of local geometry. The effects of capillary number and local geometry on the droplet formation regimes, droplet sizes and monodispersity as well as droplet generation frequency are examined and analyzed. Once identified, a drop formation regime diagram is provided to quantitatively describe the respective regime of dripping, dripping-jetting transition, and jetting in axisymmetric microfluidics, depending on the Capillary number and orifice radius. The results indicate that, the existence of focusing orifice induces a strong hydrodynamic focusing effect, causing the droplet formation behaviors in flow-focusing microfluidics depart from the co-flow one. The dripping-jetting transition regime occurs at a smaller Capillary number in flow-focusing microfluidics, and the droplets produced by flow-focusing microfluidics are smaller than those in co-flow system with wider size distribution and higher frequency. Interestingly, the droplet formation in flow-focusing microfluidics is significantly affected by the orifice radius while it is insensitive to the orifice length. In addition, when the orifice radius is sufficiently small or the Capillary number is larger than 0.3, only the jetting regime is observed. As the orifice radius increases, the regions of Capillary number for both the dripping-jetting transition regime and dripping regime turn to be larger.
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DOI：
10.1016/j.jcp.2014.08.034
发表时间：
2014-12
期刊：
J. Comput. Phys.
影响因子：
--
作者：
K. Yokoi
通讯作者：
K. Yokoi
影响因子：
4.6
作者：
Chunfeng Zhou;P. Yue;James J. Feng
通讯作者：
Chunfeng Zhou;P. Yue;James J. Feng
用于多重检测的条码颗粒的微流控合成
影响因子：
13.3
作者：
Zhao Yuanjin;Cheng Yao;Shang Luoran;Wang Jie;Xie Zhuoying;Gu Zhongze
通讯作者：
Gu Zhongze
影响因子：
8.6
作者：
Ganan-Calvo, AM
通讯作者：
Ganan-Calvo, AM
DOI：
10.1103/physreve.87.013002
发表时间：
2013
期刊：
Physical review. E, Statistical, nonlinear, and soft matter physics
影响因子：
--
作者：
Yongping Chen;Liangyu Wu;Chengbin Zhang
通讯作者：
Yongping Chen;Liangyu Wu;Chengbin Zhang