Flow in a containerless liquid system: Ring-sheared drop with finite surface shear viscosity
Flow in a containerless liquid system: Ring-sheared drop with finite surface shear viscosity
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无容器液体系统中的流动：具有有限表面剪切粘度的环剪切液滴
DOI：
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发表时间：
2019
影响因子：
2.7
通讯作者：
Juan M. Lopez
中科院分区：
文献类型：
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作者：
Shreyash Gulati;F. Riley;A. Hirsa;Juan M. Lopez
环剪切液滴是微重力下的一种流动形态，其中表面张力提供了包容性，而本体中的剪切主要由表面剪切粘度的作用驱动。液滴受到两个薄接触环的约束，即，一个在南纬度静止，另一个在相同纬度但在北并且旋转。由于我们考虑的是微重力环境，因此下降并不限于很小。此外，我们允许任意小的表面剪切粘度，因此，在一般情况下，界面和体积流粘性耦合。我们的数值模拟结果表明，即使是小的表面剪切粘度（量化无量纲的Boussinesq数）可以产生一个显着的湍流体积流量在中等环旋转速率（量化雷诺数Re）。在非常低的Re下，整体流动是粘性主导的，并且表面粘度产生非常小的差异。在高Re时，如果表面粘性可以忽略不计，则二次流非常弱，并且流动倾向于固体旋转。
The ring-sheared drop is a flow configuration for microgravity, where surface tension provides containment and shear in the bulk is driven primarily by the action of surface shear viscosity. A drop is constrained by two thin contact rings, i.e., one stationary at a southern latitude and the other at the same latitude but in the north and rotating. Since we consider a microgravity setting, the drop is not restricted to being small. Furthermore, we allow for arbitrarily small surface shear viscosity, so that in general the interfacial and bulk flows are viscously coupled. Our numerical simulations show that even small surface shear viscosity (quantified nondimensionally by a Boussinesq number) can produce a significant meridional bulk flow at moderate ring rotation rates (quantified by a Reynolds number Re). At very low Re, the bulk flow is viscously dominated and surface viscosity makes very little difference. At high Re, the secondary flow is very weak if the surface viscosity is negligible and the flow tends toward solid-body rotation.