Friction law in dense granular flows
Friction law in dense granular flows
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DOI：
10.1016/j.powtec.2008.04.061
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发表时间：
2009-03
影响因子：
5.2
通讯作者：
F. Chevoir;J. Roux;F. D. Cruz;P. Rognon;G. Koval
中科院分区：
文献类型：
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作者：
F. Chevoir;J. Roux;F. D. Cruz;P. Rognon;G. Koval
致密颗粒流制度（准静态和碰撞制度之间的中间）的理解最近取得了显着进展。我们将审查的结果有关的摩擦法，我们已经获得了离散的数值模拟的帮助下，在各种几何形状（均匀平面剪切，环形剪切和斜面）的磁盘组件的流动。在无粘性准单分散和刚性颗粒的情况下，有效摩擦系数的依赖关系的分析，剪切比法向应力，剪切状态（由剪切速率和压力定义）和材料的机械特性，使制定当地的本构关系成为可能。这表明了一个无量纲参数的关键作用，称为惯性数，它规则的摩擦定律在密集的制度。在双分散流的情况下，只要考虑颗粒的平均直径，这一定律仍然成立。一旦引入表征内聚强度的第二个无量纲数，在内聚颗粒的情况下也是如此。
The understanding of the dense granular flow regime (intermediate between quasi-static and collisional regimes) has recently progressed significantly. We shall review the results concerning the friction law, which we have obtained with the help of discrete numerical simulations of flow of assemblies of disks in various geometries (homogeneous plane shear, annular shear and inclined plane). In the case of cohesionless quasi-mono-dispersed and rigid grains, the analysis of the dependencies of the effective friction coefficient, ratio of shear to normal stress, on the shear state (defined by the shear rate and pressure) and on the mechanical characteristics of the material has made possible the formulation of a local constitutive law. This has shown the crucial role of a dimensionless parameter, called inertial number, which rules the friction law in the dense regime. This law remains true in the case of bi-dispersed flows, as early as the average diameter of the grains in taken into account. It is also true in the case of cohesive grains, once a second dimensionless number, characterizing the intensity of cohesion, is introduced.