Newsletter 31 May 2007

In this paper, results are presented on asymmetric sloshing in partially filled circular cylinders subjected to horizontal, periodic forcing, as well as geyser formation and the subsequent axi-symmetric sloshing that is caused by a sudden change in Bond number. Asymmetric sloshing is controlled by three parameters that are the liquid depth parameter, the frequency offset (depending on forcing frequency and forcing amplitude) and the damping. The results cover a wide range of forcing frequencies and forcing amplitudes in the asymptotic limit of large fluid depth and low viscosity liquids. Emphasis is placed on the bounds of existence of the different wave amplitude responses, namely planar waves, swirling waves and breaking waves. In the chaotic regime wave breaking occurs quasi periodically: growth of planar wave amplitude, collapse, irregular swirl and again growth of planar wave amplitude. Geyser formation and axi-symmetric sloshing is initiated by dambreak experiments. This problem is encountered in liquid-propellant fuel tanks where under micro-gravity conditions the liquid rises near the container wall; a sudden increase in axial acceleration can cause geyser formation followed by violent liquid sloshing and gas entrainment.