Marangoni effects on a thin liquid film coating a sphere with axial or radial thermal gradients
Marangoni effects on a thin liquid film coating a sphere with axial or radial thermal gradients
复制标题
DOI：
10.1063/1.4991580
复制
发表时间：
2016-11
影响因子：
4.6
通讯作者：
D. Kang;A. Nadim;M. Chugunova
中科院分区：
文献类型：
--
作者：
D. Kang;A. Nadim;M. Chugunova
我们研究了在重力、表面张力和热梯度作用下覆盖在球外表面的液体薄膜的时间演化。我们推导了薄膜动力学模型的四阶非线性偏微分方程，包括由表面张力σ对温度t的依赖引起的Marangoni项。我们考虑了轴向或径向热梯度的两种不同的施加温度分布。我们分析了均匀涂层在小扰动下的稳定性，并在COMSOL中对一系列参数值进行了数值模拟。在轴向温度梯度的情况下，我们发现稳定状态要么是均匀的薄膜厚度，要么是流体积聚在底部或接近顶部，这取决于薄膜中液体的总量，决定了重力或马兰戈尼效应是否占主导地位。这为通过监测薄膜的厚度分布来间接测量dσ/dT提供了一种可能的方法。在…
We study the time evolution of a thin liquid film coating the outer surface of a sphere in the presence of gravity, surface tension, and thermal gradients. We derive the fourth-order nonlinear partial differential equation that models the thin film dynamics, including Marangoni terms arising from the dependence of surface tension σ on temperature T. We consider two different imposed temperature distributions with axial or radial thermal gradients. We analyze the stability of a uniform coating under small perturbations and carry out numerical simulations in COMSOL for a range of parameter values. In the case of an axial temperature gradient, we find steady states either with uniform film thickness or with the fluid accumulating at the bottom or near the top of the sphere, depending on the total volume of liquid in the film, dictating whether gravity or Marangoni effects dominate. This suggests a potential method for the indirect measurement of dσ/dT by monitoring the thickness profile of the thin film. In ...