SIMPLE VIEWS ON CORNERED CONTACT LINES NEAR INSTABILITY

International audienceDrops sliding down a partially wetting plate develop a sharp, cornered tail that above a critical speed emits little droplets. Similar contact line shapes and instabilities appear in coating and splashing and owing to the three-dimensional corner geometry the flow requires complicated modeling. Here we propose a simple comprehensive view of recent theoretical efforts, which describe these phenomena using the lubrication approximation. In particular, we derive explicit formulas for the opening angle of the corner and the curvature at the tip as a function of drop velocity. We present a detailed comparison of the model predictions with experimental results, confirming the strength of lubrication-based models to describe wetting phenomena, even for complicated geometries