Citation

Lim, Elaine and Hung, Yew Mun and Tan, Boon Thong (2017) A hydrodynamic analysis of thermocapillary convection in evaporating thin liquid films. International Journal of Heat and Mass Transfer, 108 (Part A). pp. 1103-1114. ISSN 0017-9310

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Abstract

Evaporation in a thin film induces pronounced temperature gradient and surface tension gradient along the liquid-vapor interface and in turn engenders thermocapillary flow. This study aims to investigate the fluid flow characteristics attributed to the thermocapillarity in an evaporating thin liquid film of polar and nonpolar liquids. A numerical steady-flow model is derived based on the fundamental principles of fluid flow and heat transfer by applying the long-wave evolution technique. To scrutinize the underlying physical transport phenomena associated with the significance of thermocapillary effect in an evaporating thin liquid film, we investigate the hydrodynamic characteristics of thermocapillary convection which is typically characterized by the recirculation flow patterns. The two-dimensional recirculation flow patterns in different excess-temperature regimes are analyzed and a critical turning point at where the flow is reversed due to the thermocapillary action can be identified. Compared to other working fluids, water depicts a unique thermocapillary flow characteristic where its flow lines manifests in the form of swirls along the liquid-vapor interface. The normal and the shear stress distributions further provide a clearer picture on the strength of thermocapillarity to identify the manifestation of thermocapillary flow. The analysis of flow patterns and hydrodynamic behaviors of evaporating thin liquid films provide essential insights in discerning the occurrence of thermocapillary flow as well as the significance of thermocapillarity in polar and nonpolar liquids.

Item Type:	Article
Uncontrolled Keywords:	Critical turning point, Evaporating thin film, Recirculation flow pattern, Thermocapillary convection
Subjects:	Q Science > QD Chemistry > QD450-801 Physical and theoretical chemistry
Divisions:	Faculty of Engineering and Technology (FET)
Depositing User:	Ms Suzilawati Abu Samah
Date Deposited:	21 Jul 2020 03:47
Last Modified:	21 Jul 2020 03:47
URII:	http://shdl.mmu.edu.my/id/eprint/6954

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