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摘要
We study granular avalanches in a slightly perturbed pile of beads confined in a narrow container. A realistic model based on a discrete element method has been adapted to generate the bead pile and for starting avalanches. The pile evolves by releasing single grains from a random location within a small region on top of the granular heap. Each added grain might cause an avalanche, and such avalanches have variable size and duration. After performing a thorough relaxation, we compare the new microstate with the old one and calculate the size of the avalanches as regards mass flow, mass discharge and energy. The time series analysis shows that all these avalanches are uncorrelated. We also find that mass displacement avalanches follow a power-law distribution over almost three decades, but avalanches of gravitational potential energy and avalanches of mass discharge behave differently. Besides this, we observe that the avalanche statistics depends on the system's linear size and the details of the interactions. We also examine the impact of the randomness of the imposed perturbation and realize that for some specific microstates, the short time statistics depends heavily on the initial configuration.
- 出版日期2014-4
