Unveiling thermocapillary convection in pure water drops

Alexandros Askounis, Huacheng Zhang, Dejian Zhang, Yutaku Kita, Gyoko Nagayama, Masamichi Kohno, Yasuyuki Takata, Khellil Sefiane

Research output: Contribution to journalConference article

Abstract

The existence of thermocapillary/Marangoni convection in pure water drops has been a hotly debated area over the last few years. In this paper, we report the induction of Marangoni convection in pure water drops by localized laser heating and visualized via high speed infrared and optical cameras. The optical camera recorded the evolution of drop shape over time and the infrared camera provided the spatiotemporal evolution of the temperature across the surface of the water drop. Localized heating induced a temperature gradient, which gave rise to a surface tension and eventually thermal and liquid flows within the drop. This flow manifested as twin vortices, which after experimental and theoretical arguments was attributed to Marangoni convection. We present, here, the influence of surface wettability which was found to play a major role in the convective patterns. Moreover, heating location and power on both the Marangoni convection patterns and the evaporation kinetics of the drops.

Original languageEnglish
Pages (from-to)809-814
Number of pages6
JournalInternational Heat Transfer Conference
Volume2018-August
DOIs
Publication statusPublished - 2018
Event16th International Heat Transfer Conference, IHTC 2018 - Beijing, China
Duration: Aug 10 2018Aug 15 2018

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes

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