Droplet formation and breakup dynamics in microfluidic flow-focusing devices: From dripping to jetting
Droplet formation and breakup dynamics in microfluidic flow-focusing devices: From dripping to jetting
复制标题
微流控流动聚焦装置中的液滴形成和破碎动力学：从滴落到喷射
DOI：
10.1016/j.ces.2012.08.039
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发表时间：
2012-12-24
影响因子：
4.7
通讯作者：
Li, Hua Z.
中科院分区：
文献类型：
--
作者：
Fu, Taotao;Wu, Yining;Li, Hua Z.
对微流控聚焦装置中液滴的形成和破碎动力学进行了实验研究。在600微米和400微米宽的方形微通道中，粘度较大的液体分散成粘度较低的液体。在滴加过程中，当两相粘度比较低时，分散丝束最小宽度随停留时间的变化符合与初始条件有关的幂函数关系，液滴尺寸与两相流速比和连续相的毛细管数相关；而对于两相粘度比较高的情况，分散丝束经历线性变薄过程，液滴尺寸随连续相的韦伯数变化。在射流状态下，稳定射流宽度受两相粘度比和流量比的影响。液滴大小与两相流量比呈幂函数关系，其指数依赖于两相粘度比。对喷油射流最大失稳模式的分析表明，最大失稳与两相粘度比有关，与两相流量比几乎无关。(C)2012爱思唯尔有限公司。保留所有权利。
Droplet formation and breakup dynamics in either dripping or jetting regimes in microfluidic flow-focusing devices were investigated experimentally. More viscous liquids were dispersed into less viscous liquids in square microchannels with 600 and 400 mu m wide, respectively. In the dripping regime, for low viscosity ratio of both phases, the variation of the minimum width of the dispersed thread with the remaining time could be scaled as a power-law relationship with exponent related to initial conditions, and the droplet size could be correlated with the flow rate ratio of both phases and the capillary number of the continuous phase; while for high viscosity ratio of both phases, the dispersed thread experiences a linear thinning procedure, and the droplet size can be scaled with the Weber number of the continuous phase. In the jetting regime, the stable jet width was affected by the viscosity ratio and flow rate ratio of both phases. And the relationship between the droplet size and the flow rate ratio of both phases could be scaled as a power-law relation with the exponent dependent on the viscosity ratio of both phases. The analysis of the mode of the maximum instability of the oil jet indicated that the most unstable instability is related to the viscosity ratio of both phases and is almost independent on the flow rate ratio of both phases. (C) 2012 Elsevier Ltd. All rights reserved.