20.500.12556/RUL-161445 Effect of surface wettability on dynamic behaviors and freezing mechanisms of water droplets impacting cold surfaces Droplet impacting and freezing on solid surfaces are ubiquitous in nature and crucial to many industrial applications, while the underlying mechanism of this phenomenon remains elusive. In this paper, the effect of surface wettability on dynamic behaviors and freezing mechanism of a water droplet impacting on a solid substrate at a fixed Weber number of 200 has been experimentally investigated at various surface temperatures from −35.2 to −10 °C. With the decrease in temperature of the superhydrophobic surface, the complete rebound behavior moves to partial rebound and ultimately to full adhesion, mainly due to the competition between the fluid dynamics and heat transfer processes. An intense prompt splashing is achieved by altering the surface wettability toward superhydrophobicity. Raising the water repellency enhances the lift of the lamella rim during the initial droplet spreading. The receding velocity on superhydrophobic surfaces is about ten times larger than that on hydrophobic surfaces, while it is barely affected by the surface and droplet temperatures. Three distinct freezing shapes are observed in the experiments, namely, spherical ice, irregular ice, and central cap ice, and those can be explained through the analysis of the differences between the time for the onset of freezing and receding time. Some cases of droplet freezing after full receding, also known as spherical ice, include two freezing stages. First, the liquid–gas interface freezes within a short period. Next, the remaining liquid freezes upward because the evaporation through the liquid–gas interface leads to the temperature of this interface being lower than the liquid–surface interface temperature. A phase diagram described by the final equilibrium contact factor and the surface temperature reveals the conditions to form different freezing processes or to remain a liquid state. phase transitions heat transfer infrared imaging ultrahydrophobicity gas liquid interfaces hydrophobic effect fluid dynamics droplet rebound droplet freezing superhydrophobicity fazni prehodi prenos toplote infrardeča termografija ultrahidrofobnost fazna meja plin-kapljevina hidrofobni učinek dinamika fluidov odboj kapljic zmrzovanje kapljic superhidrofobnost true false true Angleški jezik Slovenski jezik Članek v reviji 2024-09-11 09:36:55 2024-09-11 09:37:05 2025-04-03 10:52:56 0000-00-00 00:00:00 2024 0 0 22 str. iss. 9, art. 092004 Vol. 36 Sep. 2024 0000-00-00 PostprintKoncna Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 532:536.2 1070-6631 10.1063/5.0222155 207081987 Shang,_..._-_Effect_of_surface_wettability_on_dynamic_behaviors_and_freezing_mechanisms_of_water_droplets_impacting_cold_surfaces.pdf Shang,_..._-_Effect_of_surface_wettability_on_dynamic_behaviors_and_freezing_mechanisms_of_water_droplets_impacting_cold_surfaces.pdf 1 C7E17537318F293305AF5021F01F8E00 60d3d0ed3019ac0e384a6507f4c7ba132529c56c8f64d8d0562661d768d9f15e 4ae55bc0-7011-11ef-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=190377 https://pubs.aip.org/aip/pof/article-abstract/36/9/092004/3311177/Effect-of-surface-wettability-on-dynamic-behaviors?redirectedFrom=fulltext 1 98f49252-7010-11ef-b232-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=190376 Fakulteta za strojništvo 0 0 0