Inverse-thermocapillary evaporation in a thin liquid film of self-rewetting fluid
| Autor: | Tze Cheng Kueh, Yew Mun Hung, Elaine Lim |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Applied Mathematics Mechanical Engineering Flow (psychology) Evaporation Thermodynamics 02 engineering and technology 01 natural sciences 010305 fluids & plasmas Computer Science Applications Surface tension 020303 mechanical engineering & transports 0203 mechanical engineering Mechanics of Materials 0103 physical sciences Heat transfer Working fluid Thin film Current (fluid) Microscale chemistry |
| Zdroj: | International Journal of Numerical Methods for Heat & Fluid Flow. 31:1124-1143 |
| ISSN: | 0961-5539 |
| DOI: | 10.1108/hff-05-2020-0266 |
| Popis: | Purpose The present study aims to investigate the inverse-thermocapillary effect in an evaporating thin liquid film of self-rewetting fluid, which is a dilute aqueous solution (DAS) of long-chain alcohol. Design/methodology/approach A long-wave evolution model modified for self-rewetting fluids is used to study the inverse thermocapillary characteristics of an evaporating thin liquid film. The flow attributed to the inverse thermocapillary action is manifested through the streamline plots and the evaporative heat transfer characteristics are quantified and analyzed. Findings The thermocapillary flow induced by the negative surface tension gradient drives the liquid from a low-surface-tension (high temperature) region to a high-surface-tension (low temperature) region, retarding the liquid circulation and the evaporation strength. The positive surface tension gradients of self-rewetting fluids induce inverse-thermocapillary flow. The results of different working fluids, namely, water, heptanol and DAS of heptanol, are examined and compared. The thermocapillary characteristic of a working fluid is significantly affected by the sign of the surface tension gradient and the inverse effect is profound at a high excess temperature. The inverse thermocapillary effect significantly enhances evaporation rates. Originality/value The current investigation on the inverse thermocapillary effect in a self-rewetting evaporating thin film liquid has not been attempted previously. This study provides insights on the hydrodynamic and thermal characteristics of thermocapillary evaporation of self-rewetting liquid, which give rise to significant thermal enhancement of the microscale phase-change heat transfer devices. |
| Databáze: | OpenAIRE |
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