Application of micro particle shadow velocimetry μPSV to two-phase flows in microchannels
Application of micro particle shadow velocimetry μPSV to two-phase flows in microchannels
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DOI：
10.1016/j.ijmultiphaseflow.2014.02.005
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发表时间：
2014-06-01
影响因子：
3.8
通讯作者：
Thome, J. R.
中科院分区：
文献类型：
--
作者：
Khodaparast, S.;Borhani, N.;Thome, J. R.
微粒子阴影测速（mu PSV）在本研究中进行的同时速度测量和界面跟踪液-液和气-液两相流通过圆形微通道直径为5001 μ m。使用非相干LED光源的背光照明，结合液相、管壁材料和通道外部介质的完全折射率匹配，允许在液滴内部和周围，甚至接近界面和边界进行测速。此外，提出并实现了后处理方法，以解决孤立的气泡和不混溶液滴在层流中的运动定量。特别是，同时测量的局部瞬时相速度和流速，液膜动力学和它的厚度，形状和体积的分散相，并在前面和后面的气泡的发展长度获得使用一个单一的序列的灰度阴影图像。这些结果对验证相应的数值模拟程序具有参考价值。据信，这种方法显着降低了实验装置的尺寸和成本，同时提高了测量的准确性和可靠性。(C)2014爱思唯尔有限公司版权所有。
Micro particle shadow velocimetry (mu PSV) is performed in the present study for simultaneous velocity measurement and interface tracking in both liquid-liquid and gas-liquid two-phase flows through circular microchannels of 5001 mu m diameter. The back-lit illumination using a non-coherent LED light source, combined with full refractive index matching of the liquid phases, the tube wall material and the channel exterior medium, allowed velocimetry to be done both within and around the liquid droplets, and even close to the interfaces and boundaries. Moreover, post-processing methods are proposed and implemented in order to resolve motion of isolated gas bubbles and immiscible liquid droplets in laminar flows quantitatively. In particular, simultaneous measurements of local instantaneous phase velocities and flow rates, liquid film dynamics and its thickness, shape and volume of the dispersed phase, and development length in front and at the back of the bubbles are obtained using one single sequence of gray scale shadowgraphy images. Such results are valuable for validation of corresponding numerical simulation codes. It is believed that this approach significantly reduces the size and cost of the experimental setup while increasing the accuracy and reliability of the measurements. (C) 2014 Elsevier Ltd. All rights reserved.