Impact of a cylinder

In Gekle et al. Phys. Rev. Lett. 100, 084502 (2008) we replace the impacting disc by a long, smooth cylinder. While for an impacting disc the depth at which the cavity closes scales continuously with the impact velocity, we show that for a cylinder the closure depth does not strictly obey the expected scaling. Instead, it displays distinct regimes separated by discrete jumps which are consistently observed in experiment and numerical simulations. We quantitatively explain this behavior as a consequence of capillary waves which are created when the cylinder top passes the water surface.

Figure 1: Comparison of the experimental closure depth (black crosses) with the numerical data (blue diamonds). The insets illustrate the shape of the cavity at pinch-off for one representative of each regime (axes are the same for all insets). The regimes are determined by which local minimum first meets its counterpart on the central axis.

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Info: Devaraj van der Meer