Numerical study of compound drop mobility over a surface having wettability difference

Abstract

Three-dimensional numerical simulations have been performed to analyze the effect of wettability difference on a compound droplet through biphilic and wettability gradient surfaces. Three distinct drop–drop configuration regimes during translation are found in both types of surfaces, as the contact angle difference on the surface is varied. Along with these advancing, rear, and central locations of core drop regimes, lens like drop–drop configuration is also realized over the biphilic surface by considering hydrophobic contact angle variation. On the biphilic surface, drop–drop configurations are also reported from simulation with different core-to-shell volume ratios and inversion of core and shell liquids.