E3S Web of Conferences (Jan 2021)

Modeling the Evaporation of Drying Sessile Droplets with Buoyancy Driven Internal Convection

  • Akdag Osman,
  • Akkus Yigit,
  • Çetin Barbaros,
  • Dursunkaya Zafer

DOI
https://doi.org/10.1051/e3sconf/202132104013
Journal volume & issue
Vol. 321
p. 04013

Abstract

Read online

Droplet evaporation is a fundamental phenomenon encountered in diverse applications such as inkjet printing, DNA mapping, film coating, and electronics cooling. Modeling the evaporation process of a sessile droplet is complicated because of the coupling of several physical phenomena occurring in different phases and various magnitudes such as the buoyant convection of the liquid in millimeter size droplets and that of the surrounding air/water vapor mixture, in the order of meters. In this study, the theoretical framework presented previously for the steadily fed droplets [Int J Therm Sci, 158 (2020) 106529] is extended to resolve the evaporation of drying droplets with a pinned contact line. Based on the quasi-steady-state assumption, buoyant convection inside the droplet and diffusive-convective transport of vapor in the gas domain are modeled. As a test case, drying process of a water droplet with a 68° initial contact angle on a heated substrate is simulated and the predictions of the model are interpreted.

Keywords