蒸发液层对流稳定性理论与实验研究进展

综述了蒸发液层稳定性理论分析和蒸发对流实验研究方面的最新进展. 首先回顾历史上经典的单层流Marangoni不稳定性分析.利用经典的单层流模型可以很好解释无蒸发液层的稳定性特性, 但是由于经典的单层流模型没有考虑蒸汽层与液层之间的动力学耦合关系,所以不能完全解释蒸发液层的Marangoni不稳定性特性.有的学者建立了考虑蒸汽层与液层的热耦合与动力学耦合关系的两层流模型, 并采用了界面温度连续这样的假设. 而在实验的观测中, 蒸发界面处的温度是不连续的, 特别是在蒸发量比较大的情况下, 汽/液界面处温度跳跃很明显. 由于界面温度连续假设在处于非平衡状态的系统中是不成立的, 所以这些模型虽然能给出一些新的有关系统稳定性的特性,但还是不能完全解释蒸发液层的Marangoni不稳定性的特性, 特别是为什么从底部冷却液层的时候, 在实验中仍然能够观察到Marangoni对流涡胞的出现的原因. 本文总结了前人的研究成果, 同时给出了蒸发系统的动力学建模过程和实验研究方法,并对各种模型的稳定性特性进行了总结. 最后, 指出了现有理论中存在的问题和有待进一步研究的问题. 

THE PROGRESSES IN THEORETICAL AND EXPERIMENTAL RESEARCHES ON THE EVAPORATIVE CONVECTION INSTABILITIES IN HORIZONTAL LIQUID LAYERS

The progresses in researches of the convective instabilities are reviewed in this paper. First, the analyses of the instabilities of the classic one layer model are introduced. Where the dynamic coupling between the vapor layer and the liquid layer is not considered, so evaporating instabilities could not be explained. In order to introduce the dynamic coupling between the vapor layer and the liquid layer, two sided models with an evaporating interface were proposed. The assumption of the continuity of the temperature at the interface is usually adopted. However, the temperature at the evaporating interface was found discontinuous in experiments, especially when the evaporating flux is large. Because the assumption of the continuity of the temperature is not true in a non-equilibrium system, these models can not explain the Marangoni-B6nard instabilities of the evaporating layer, especially when the liquid layer is cooled from below. This paper reviews previous research results and dynamic models. We discuss the Marangoni-Benard instabilities of these models, and point out some open problems for future researches.