Dependent Droplet Impact Dynamics on Flat and Textured Surfaces

Ali Dhinojwala

Abstract

Dropletimpactdynamics determines the performance of surfaces used in many applications such as anti-icing, condensation, boiling, and heat transfer. We study impactdynamics of water droplets on surfaces with chemistry/texture ranging from hydrophilic to superhydrophobic and across a temperature range spanning below freezing to near boiling conditions. Dropletretraction shows very strong temperature dependence especially on hydrophilicsurfaces; it is seen that lower substrate temperatures lead to lesser retraction. Physics-based analyses show that the increased viscosity associated with lower temperatures combined with an increased work of adhesion can explain the decreased retraction. The present findings serve as a starting point to guide further studies of dynamic fluid-surface interaction at various temperatures.