Rising Obstacle in a Two-dimensional Granular Bed Induced by Continuous and Discontinuous Vibrations: Dynamics Governed by Vibration Velocity

Rising motion of an intruder in a vibrated granular bed, known as the Brazil nut problem, is studied using one layer of granular bed. We examine two modes of vibration, continuous and discontinuous, to show the rising motion can be divided into initial and final stages both in the two vibration modes. We reveal that the final convection-driven regime of the rising motion is always governed by the vibration velocity.