Fischer Raphaël, Gondret Philippe, Perrin Bernard, Rabaud Marc
Lab FAST, CNRS, Université Pierre et Marie Curie-Paris 6, Université Paris-Sud, Bâtiment 502, Campus Universitaire, F-91405 Orsay cedex, France.
Phys Rev E Stat Nonlin Soft Matter Phys. 2008 Aug;78(2 Pt 1):021302. doi: 10.1103/PhysRevE.78.021302. Epub 2008 Aug 5.
A fine analysis of the statistics of dry granular avalanches in a rotating drum setup reveals that, beyond the fluctuations, the angle at which an avalanche ends is correlated experimentally to the angle at which the avalanche starts. This correlation resulting from inertia defines an intermediate "neutral" angle that characterizes the corresponding granular pile. In addition, an intensive study of the dynamics of the avalanche shows that the time duration of the avalanche is correlated to its amplitude, being smaller for higher amplitude. The time relaxation of the pile slope during any avalanche, governed by the deviation of the starting angle from the neutral angle, follows a master curve. A simple model recovers most of the results and contributes to a better understanding of the physics of the avalanche flow.
对旋转鼓装置中干颗粒雪崩统计数据的精细分析表明，除波动外，雪崩结束时的角度在实验上与雪崩开始时的角度相关。由惯性产生的这种相关性定义了一个中间“中性”角度，该角度表征了相应的颗粒堆。此外，对雪崩动力学的深入研究表明，雪崩的持续时间与其幅度相关，幅度越高持续时间越短。在任何雪崩过程中，由起始角度与中性角度的偏差所控制的堆坡时间弛豫遵循一条主曲线。一个简单的模型重现了大部分结果，并有助于更好地理解雪崩流的物理原理。
