Dynamic Contact Lines in Rotating Liquids

The equations of fluid mechanics are solved for the case of an infinite cylinder partly immersed in a liquid and rotating with a constant angular velocity. the profile shapes obtained show that there are two regions, a macroscopic, smooth, and stable region and a small region near the contact line which shows large curvatures and is unstable to small disturbances. Consequently it is suggested that the apparent dynamic contact angles observed are the results of visual extrapolation of the smooth, stable, macroscopic shapes to the solid surface. It is also shown that the effect of the fluid mechanical quantities, bulk and surface rheologies, on the apparent dynamic contact angles vary from one case to another