标题： 颗粒浮渣的流变学 显示英文标题

标题： Rheology of Granular Rafts

摘要： 宏观颗粒载流界面，称为“颗粒筏”，在简单剪切配置中已被实验研究。 从经典流变仪获得的剪切应力关系表现出与宾汉流体相同的行为，粘度随着表面分数按照类似于二维悬浮液的演变而发散。 已测量构成颗粒筏的颗粒的速度场，在稳态下。 这些测量结果揭示了类似于干颗粒材料的非局部流变行为。 在流变仪腔体的靠近墙壁处，可以观察到大局部剪切率的区域，而在腔体中间存在准静态区域。 这种流动区域是颗粒物质的特征，在扩展的动力学理论框架中进行了描述，说明了速度剖面随施加剪切应力的变化。 测量基本应变的概率密度函数，我们提供了正负基本应变之间平衡的证据。 这种行为是颗粒筏内部准静态区域的标志。 显示英文摘要

摘要： Rheology of macroscopic particle-laden interfaces, called "Granular Rafts" has been experimentally studied, in the simple shear configuration. The shear-stress relation obtained from a classical rheometer exhibits the same behavior as a Bingham fluid and the viscosity diverges with the surface fraction according to evolutions similar to 2D suspensions. The velocity field of the particles that constitute the granular raft has been measured in the stationary state. These measurements reveal non-local rheology similar to dry granular materials. Close to the walls of the rheometer cell, one can observe regions of large local shear rate while in the middle of the cell a quasistatic zone exists. This flowing region, characteristic of granular matter, is described in the framework of an extended kinetic theory showing the evolution of the velocity profile with the imposed shear stress. Measuring the probability density functions of the elementary strains, we provide evidence of a balance between positive and negative elementary strains. This behavior is the signature of a quasistatic region inside the granular raft.