Vo Thanh Trung, Nezamabadi Saeid, Mutabaruka Patrick, Delenne Jean-Yves, Radjai Farhang
Bridge and Road Department, Danang Architecture University, Da Nang, Vietnam.
LMGC, University of Montpellier, CNRS, 34060, Montpellier, France.
Nat Commun. 2020 Mar 19;11(1):1476. doi: 10.1038/s41467-020-15263-3.
Granular flows are omnipresent in nature and industrial processes, but their rheological properties such as apparent friction and packing fraction are still elusive when inertial, cohesive and viscous interactions occur between particles in addition to frictional and elastic forces. Here we report on extensive particle dynamics simulations of such complex flows for a model granular system composed of perfectly rigid particles. We show that, when the apparent friction and packing fraction are normalized by their cohesion-dependent quasistatic values, they are governed by a single dimensionless number that, by virtue of stress additivity, accounts for all interactions. We also find that this dimensionless parameter, as a generalized inertial number, describes the texture variables such as the bond network connectivity and anisotropy. Encompassing various stress sources, this unified framework considerably simplifies and extends the modeling scope for granular dynamics, with potential applications to powder technology and natural flows.
颗粒流在自然界和工业过程中无处不在，但当颗粒之间除了摩擦力和弹力之外还存在惯性、粘性和内聚相互作用时，其流变特性（如表观摩擦力和堆积分数）仍然难以捉摸。在此，我们报告了对由完全刚性颗粒组成的模型颗粒系统的此类复杂流动进行的广泛颗粒动力学模拟。我们表明，当表观摩擦力和堆积分数通过其与内聚相关的准静态值进行归一化时，它们由一个单一的无量纲数控制，该无量纲数由于应力可加性，考虑了所有相互作用。我们还发现，这个无量纲参数作为广义惯性数，描述了诸如键网络连通性和各向异性等织构变量。这个统一框架涵盖了各种应力源，极大地简化并扩展了颗粒动力学的建模范围，在粉末技术和自然流动方面具有潜在应用。
