Dynamic Behavior of the Liquid Flow Coalescing with a Droplet in Hydrophobic Microchannels.
Dynamic Behavior of the Liquid Flow Coalescing with a Droplet in Hydrophobic Microchannels.
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DOI：
10.1166/jnn.2015.9674
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发表时间：
2015-04
影响因子：
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通讯作者：
Chen Rong;L. Shuzhe;Wang Hong;L. Qiang;Z. Xun;F. Qinlin;He Xuefeng;W. Zhibin
中科院分区：
文献类型：
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作者：
Chen Rong;L. Shuzhe;Wang Hong;L. Qiang;Z. Xun;F. Qinlin;He Xuefeng;W. Zhibin
在本研究中，使用 ANSYS-Fluent 14.5 中实施的耦合流体体积与水平集 (CLSVOF) 界面跟踪方法结合连续表面力 (CSF) 模型，对压力驱动流动条件下疏水微通道中移动液柱与固着液滴聚结的动态行为进行了数值研究。数值结果表明，运动的液柱与液滴之间的合并可以加速原始液柱的运动。还研究了润湿性、水头压力以及液滴尺寸和位置的影响。研究发现，速度增量比随着接触角的增大和水头压力的减小而增大。较大的液滴和液滴与入口之间的较小距离可以由于较高的表面能和较低的粘性耗散能而导致较大的速度增量比。 10000 µm3 液滴位于宽 100 µm、长 300 µm、接触角 120° 的微通道中 200 µm 处时，获得的最大速度增量比为 0.17。
In this study, the dynamic behavior of the moving liquid column coalescing with a sessile droplet in a hydrophobic microchannel under pressure driven flow conditions is numerically investigated using coupled Volume of Fluid with Level Set (CLSVOF) interface tracking method implemented in ANSYS-Fluent 14.5 in conjunction with the continuum surface force (CSF) model. Numerical result reveals that the coalescence between the moving liquid column and droplet can accelerate the original liquid column movement. Effects of the wettability, head pressure, and droplet size and position are also investigated. It is found that the velocity increment ratio increases with increasing the contact angle and decreasing the head pressure. Larger droplet and smaller distance between the droplet and inlet can result in a larger velocity increment ratio as a result of higher surface energy and lower viscous dissipation energy. The maximum velocity increment ratio of 0.17 is obtained with a 10000-µm3 droplet that is positioned at 200 µm in a microchannel with 100 µm in width and 300 µm in length and contact angle of 120°.