Role of resisting shear on the shedding drops

When a drop sheds from a surface, the drag given by the shear flow balances the adhesion. But during shedding, i.e., when the drop is in motion, two more resisting shear, wedge shear, and bulk shear induce inside due to the complexity of the shape, viscosity, and velocity of the drop. The role of the total shear compared to adhesion when a drop is in motion is shown. The resisting shear is found to increase with the viscosity and velocity of the drop, irrespective of the wettability of the surface. The velocity is higher for lower viscosity drops at a given Weber number (We). The total resisting force, adhesion, and shear are found to be lower. Among the total shear, the wedge shear is higher than the bulk one since the function of the mean contact angle for the wedge flow is higher. The function is found from a model developed.

Automated summary

When a droplet is in motion, resisting shear increases with viscosity and velocity, compared to adhesion, regardless of surface wettability. The total shear, with wedge shear being higher than bulk shear, is found to decrease with lower viscosity and higher velocity drops at a given Weber number.