The Role of Slip and No Slip Behavior on Droplet Impingement

Abstract

For the identification of role of slip and no slip conditions at the solid–liquid interface in case of hydrophobic, superhydrophilic, and superhydrophobic surfaces, the experimentally determined velocity profiles are analyzed. Before experimentation, each surface was characterized by using scanning electron microscope (SEM), two-dimensional, and three-dimensional surface profilometer. The impact mapping results reveal that in case of hydrophobic surface, first no slip condition is achieved and then slip condition is noticed. Conversely, for superhydrophilic surface, initially slip and then no slip conditions are observed. Furthermore, in case of superhydrophobic surface, slip behavior is observed throughout the process for the dimensionless time ranges 0.06–0.94 and this behavior of the process promotes local enhancement of viscous and capillary forces. The experimentally obtained results are further tried to validate with the help of theoretical and visual observations.