Velocity profile in a two-layer Kolmogorov-like flow
Velocity profile in a two-layer Kolmogorov-like flow
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DOI：
10.1063/1.4873417
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发表时间：
2014-05-01
影响因子：
4.6
通讯作者：
Schatz, Michael F.
中科院分区：
文献类型：
--
作者：
Suri, Balachandra;Tithof, Jeffrey;Schatz, Michael F.
在这篇文章中，我们讨论了两种不相容流体在水平分层的浅层中的流动。顶层是电磁驱动的电解液，底层是介电流体。采用准二维近似，假定水平流动的方向与垂直坐标无关，导出了描述水平流动演化的广义二维涡量方程。此外，我们还推导出水平速度场垂直剖面的表达式。用粒子图像测速仪测量了电解液-空气和电解液-电介质界面的水平速度场，验证了定常和自由衰减类Kolmogorov流的水平速度及其垂直分布的理论预测。我们的分析表明，通过增加电解液相对于介质的粘度，可以显著改善电解液中流动的均匀性，从而在分析预测和实验测量之间产生很好的一致性。(C)2014 AIP出版有限责任公司。
In this article, we discuss flows in shallow, stratified horizontal layers of two immiscible fluids. The top layer is an electrolyte which is electromagnetically driven and the bottom layer is a dielectric fluid. Using a quasi-two-dimensional approximation, which assumes a horizontal flow whose direction is independent of the vertical coordinate, we derive a generalized two-dimensional vorticity equation describing the evolution of the horizontal flow. Also, we derive an expression for the vertical profile of the horizontal velocity field. Measuring the horizontal velocity fields at the electrolyte-air and electrolyte-dielectric interfaces using particle image velocimetry, we validate the theoretical predictions of the horizontal velocity and its vertical profile for steady as well as for freely decaying Kolmogorov-like flows. Our analysis shows that by increasing the viscosity of the electrolyte relative to that of the dielectric, one may significantly improve the uniformity of the flow in the electrolyte, yielding excellent agreement between the analytical predictions and the experimental measurements. (C) 2014 AIP Publishing LLC.