Brewster Robert, Silbert Leonardo E, Grest Gary S, Levine Alex J
Department of Chemistry and Biochemistry, UCLA, Los Angeles, California 90095, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2008 Jun;77(6 Pt 1):061302. doi: 10.1103/PhysRevE.77.061302. Epub 2008 Jun 11.
The validity of the Bagnold constitutive relation in gravity-driven granular flow down an inclined plane is studied by discrete element (DEM) simulations. In the limit of infinitely hard particles, the Bagnold relation is known to hold exactly. We determine deviations from this relation as a function of all parameters governing interparticle interactions. These include elastic compliance, inelastic dissipation, friction coefficient, and interparticle cohesion. We find significant deviations from Bagnold rheology in some regions of this parameter space and propose a generalized Bagnold relation to account for this effect. Moreover, we note a significant correlation between the breakdown of Bagnold rheology in the bulk and the appearance of a long-time tail in the two-particle contact time distributions.
通过离散元（DEM）模拟研究了重力驱动下颗粒在倾斜平面上流动时Bagnold本构关系的有效性。在颗粒无限硬的极限情况下，已知Bagnold关系能精确成立。我们确定了与该关系的偏差作为控制颗粒间相互作用的所有参数的函数。这些参数包括弹性柔度、非弹性耗散、摩擦系数和颗粒间内聚力。我们发现在该参数空间的某些区域与Bagnold流变学存在显著偏差，并提出了一个广义Bagnold关系来解释这种效应。此外，我们注意到整体中Bagnold流变学的破坏与两颗粒接触时间分布中长时间尾部的出现之间存在显著相关性。
