Explosive boiling of argon nanofilms in the Wenzel or Cassie state on high-temperature nanopillar-arrayed surfaces
Journal
International Journal of Thermal Sciences
Journal Volume
172
Date Issued
2022
Author(s)
Abstract
In this work, phase change behaviors of liquid argon nanofilms in the Wenzel or Cassie state on gold nanopillar-arrayed surfaces are investigated via molecular dynamics (MD) simulations. The results show that the argon films with 4.0 and 7.0 nm thickness have lower onset temperatures of explosive boiling than that with 1.5 nm thickness. At the same wall temperature of 190 K and film thickness of 4.0 nm, evaporation only is observed for the films in the Cassie state, whereas explosive boiling is noted for the films in the Wenzel state, indicating that the Wenzel state has a lower onset temperature. The nanopillar height has significant effects on the occurrence of explosive boiling. On the nanopillar-arrayed surfaces with an intrinsic contact angle of 35°, liquid films are always in the Wenzel state, and explosive boiling occurs at a prolonged time for the surface with a larger nanopillar height of 2.040 nm, attributing to the larger energy barrier for the Wenzel-to-Cassie wetting transition. On the nanopillar-arrayed surfaces with an intrinsic contact angle of 101°, films are initially in the Wenzel state for the smaller nanopillar height of 1.224 nm; however, they transition to the Cassie state for the larger nanopillar height of 2.040 nm, leading to the prolonged explosive boiling. ? 2021 Elsevier Masson SAS
Subjects
Cassie state
Explosive boiling
Molecular dynamics simulations
Nanofilm
Wenzel state
Argon
Contact angle
Explosives
Liquefied gases
Liquid films
Nanostructures
Wetting
Highest temperature
Liquid argon
Low onset temperatures
Nano films
NanoPillar
Phase Change
Wall temperatures
Molecular dynamics
SDGs
Type
journal article