Capillary collapse of a cavity in microgravity

An investigation of the capillary collapse of a nonspherical cavity generated by the temporary impingement of an air jet at a free liquid surface is presented. In the experiments, the collapse of the cavity takes place in a microgravity environment where the dynamics are driven by capillary forces and are not altered by gravity. Microgravity conditions are achieved by using the unique low-gravity environment of a drop tower. The collapse of a spherical cavity, an approximation for a bursting bubble at a liquid gas interface, has been well studied and is known to give rise to a liquid jet that breaks up into droplets. This investigation shows that the capillary collapse of these nonspherical cavities can also give rise to a liquid jet. The jet velocity is shown to depend on the aspect ratio of the cavity. Simulations are performed to further elucidate the cavity collapse phenomena.