Defrosting behavior and performance on vertical plate for surfaces of varying wettability

Abstract

The defrosting behaviors and performances of super-hydrophilic, bare, and super-hydrophobic surfaces were experimentally investigated along different frost layer densities on a vertical plate. The defrosting behavior can be divided into three types based on the size of the water permeation layer. The defrosting behaviors of bare and super-hydrophilic surfaces were similar, whereas the super-hydrophobic surface behaved differently by allowing the frost layer to be easily removed from its surface. Defrosting performance was evaluated based on defrosting time and water retention ratio. Within the low frost layer density range, defrosting time did not depend on surface characteristics. However, as the density of the frost layer increased, defrosting time increased in the bare and super-hydrophilic surfaces, whereas in the super-hydrophobic surface, that time tended to decrease rather than increase. Water retention ratio was highest on the super-hydrophilic surface and lowest on the super-hydrophobic surface in all frost layer densities. Therefore, the defrosting performance of a super-hydrophobic surface was outstanding over a wide range of frost layer densities. (C) 2017 Elsevier Ltd. All rights reserved.