On the depinning of a drop of partially wetting liquid on a rotating cylinder

Abstract

We discuss the analogy of the behaviour of films and drops of liquid on a rotating horizontal cylinder on the one hand and substrates with regular one-dimensional wettability patterns on the other hand. Based on the similarity between the respective governing long-wave equations we show that a drop of partially wetting liquid on a rotating cylinder undergoes a depinning transition when the rotation speed is increased. The transition occurs via a sniper bifurcation as in a recently described scenario for drops depinning on heterogeneous substrates.