Title

Stability of Thin Liquid Films Evaporating into Saturated Vapor

Abstract

Because of its importance in boiling heat transfer problems, the stability of a superheated thin liquid film, lying on a solid substrate and evaporating into saturated vapor, is studied. Ordinarily it is expected that the temperature at the vapor liquid interface is constant at the saturation temperature. However, due to the intermolecular forces of interaction, the boiling piont is a function of the thickness of the liquid layer. the stability analysis shows that because of the above feature, surface tension gradient driven flows and Marangoni instability can exist. However, the stabilizing influence of the surface tension augmented by the intermolecular forces, is very high. Using bulk values for the physical quantities, it is seen that most liquid films are stable due to the damping from the latent heat of vaporization, the usual values of which are excessively high for the instability to occur. Although in principle liquids may exist with adequately low latent heats or the physical properties in the thin films may differ sufficiently from their bulk values for the instability to occur, the conclusion that such films are stable appear to be general. © 1982.

Department(s)

Chemical and Biochemical Engineering

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 1982 Elsevier, All rights reserved.


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