Non-isothermal Evaporation of Salt Solutions on a Microstructured Surface

S. Ya Misyura

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Heat transfer of a droplet and layer during evaporation of aqueous solutions of salts has been studied. The behavior of salt solutions on a smooth and microstructured surface is compared here. Evaporation rate of aqueous salt solutions is greater for a microstructured surface than for a smooth wall. The behavior of heat transfer coefficient α can be described by two time regimes: quasi-constant values of α and significant increase in heat transfer at a multiple decrease in the liquid layer height. Measurements made with application of the particle image velocimetry showed that the structured surface increases liquid speed inside the sessile drop. The largest value of the heat transfer coefficient α on the structured surface corresponds to water for the final stage of evaporation. For salt solutions, the heat transfer coefficient is lower than that for water in the entire period of evaporation on the structured surface. The maximal excess (20–30%) of α of the structured wall above the smooth surface corresponds to the maximal height of the liquid layer at the beginning of evaporation. With increasing time, the excess is reduced. A drop of heat transfer intensification with a decrease in the layer height relates to suppression of free convection (a multiple decrease in the average velocity in the drop).

Original languageEnglish
Pages (from-to)213-229
Number of pages17
JournalNanoscale and Microscale Thermophysical Engineering
Volume22
Issue number3
DOIs
Publication statusPublished - 3 Jul 2018

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Keywords

  • aqueous salt solution
  • evaporation rate
  • heat transfer coefficient
  • Microstructured surface

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials

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