Evolution of fluid-like granular ejecta generated by sphere impact

  title={Evolution of fluid-like granular ejecta generated by sphere impact},
  author={Jeremy O. Marston and Er Qiang Li and Sigurdur T. Thoroddsen},
  journal={Journal of Fluid Mechanics},
  pages={5 - 36}
Abstract We present results from an experimental study of the speed and shape of the ejecta formed when a solid sphere impacts onto a granular bed. We use high-speed imaging at frame rates up to 100 000 f.p.s. to provide direct measurement of individual grain velocities and ejecta angles as well as the overall evolution of the granular ejecta. For larger grain sizes, the emergence velocities of the grains during the ‘early stage flow’, i.e. before the main ejecta ‘curtain’ forms, increase with… 

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