Convection, Evaporation, and Condensation of Simple and Binary Fluids in Confined Geometries
Convection, Evaporation, and Condensation of Simple and Binary Fluids in Confined Geometries
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DOI：
10.1115/mnhmt2012-75266
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发表时间：
2012-03
期刊：
影响因子：
--
通讯作者：
T. Qin;R. Grigoriev
中科院分区：
文献类型：
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作者：
T. Qin;R. Grigoriev
在无相变的情况下，具有自由表面的均匀流体层中的Rayleigh-Benard和Marangoni对流是流体力学的经典（和广泛研究的）问题。相变对对流问题有很大的影响。最值得注意的是，由于相变而在自由表面产生的显着潜热可以显着改变界面温度，从而改变热毛细应力。此外，二元流体中的差异蒸发会导致浓度场发生相当大的变化，产生溶解毛细作用应力，该应力可以与热毛细作用和浮力竞争。本演讲描述了由于水平温度梯度而产生的酒精和酒精-水混合物中对流的数值研究存在相变。我们说明了液体的组成和不可冷凝气体的存在（例如，空气）可以用来改变主导力量的平衡。特别是，通过在测试池中添加或移除空气，可以通过强调热毛细或溶液毛细应力来反转流动方向。© 2012 ASME
Rayleigh-Benard and Marangoni convection in a layer of a homogeneous fluid with a free surface in the absence of phase change is a classic (and extensively studied) problem of fluid mechanics. Phase change has a major effect on the convection problem. Most notably, significant latent heat generated at the free surface as a result of phase change can dramatically alter the interfacial temperature, and hence, the thermocapillary stresses. Furthermore, differential evaporation in binary fluids can lead to considerable variation in the concentration field, producing solutocapillarity stresses, which can compete with thermocapillarity and buoyancy.This talk describes numerical studies of convection in alcohol and alcohol-water mixtures due to a horizontal temperature gradient in the presence of phase change. We illustrate how the composition of the liquid and the presence of non-condensable gases (e.g., air) can be used to alter the balance of the dominant forces. In particular, by adding or removing air from the test cell, the direction of the flow can be reversed by emphasizing either the thermocapillary or the solutocapillary stresses.© 2012 ASME