Impact of freely falling liquid containers and subsequent jetting

When a container, partially filled with liquid, is dropped from a certain height onto a floor, it will undergo a sudden deceleration followed by a rebound. At the moment of the container impact, the free-surface meniscus experiences large radial pressure gradients forming a high-velocity surface jet. We report experimental results and scaling analysis of the jet formation, showing that the jet initiation could also occur during the sudden deceleration phase. We show that the jet velocity scales as the geometric mean of the impact velocity and curvature-deformation velocity scale. We also report results for a second-jet originating from the tip of the evolving first-jet that resembles the tubular jets observed earlier in liquid entry to a pipe problem (Lorenceau et al. in Phys Fluids 14(6):1985–1992, 2002, Bergmann et al. in J Fluid Mech 600:19–43, 2008). We show that the second-jet follows a capillary velocity scale, unlike the tubular jet. The second-jet is caused by the collapse of an unstable cavity at the first-jet tip. The cavity radius follows an inertia-capillary scaling: r ∼ ( t s - t ) 1 / 2 , where t s - t is the time to singularity. Graphical Abstract