Oscillations of free surface at the edge of short capillary tubes

Abstract Liquid gets imbibed into the capillary tube under the influence of capillary pressure. If capillary tube is shorter than Jurin height, oscillations of free surface are observed when contact line is confined by the edge of tube. Through numerical simulations and theoretic analyses, the velocity at the tube edge is determined, and the morphologies of meniscus at different stages of oscillation are identified. Finally, the oscillation period is found to be linearly correlated to r ρ L / γ through scale analysis, which is also verified by the simulation results. Discoveries in this paper show that new dynamics exists during the conversion between inertia and surface energy.