论文标题
液化水坑的2D颗粒类似物的传播：通过连续模型预测结构和动力学
Spreading of a 2D granular analogue of a liquid puddle: predicting the structure and dynamics through a continuum model
论文作者
论文摘要
当沙子从漏斗中流出到表面时，通过摩擦稳定的三维桩在扩散时会变得更高。在这里，我们研究了一个理想化的二维类似物：在边界处的一堆单分散油滴的扩散。在我们的系统中，液滴具有浮力，粘合剂和与沙子相反，这里的摩擦可以忽略不计。将浮力液滴添加到一次堆中。随着骨料的增长，它达到临界高度，2D桩在屏障上散布。我们发现，尽管粒度很重要，但生长过程让人联想到连续液体。我们定义了``颗粒毛细管长度''，类似于液体中的毛细管长度，该毛细血管长度通过浮力和粘附的平衡来设置骨料的临界高度。在粗粒的水平上，颗粒状毛细血管长度能够描述系统的稳态特性和动态特性，而在颗粒水平下，重复折叠事件在桩的形成中起着至关重要的作用。
When sand flows out of a funnel onto a surface, a three dimensional pile that is stabilized by friction grows taller as it spreads. Here we investigate an idealized two dimensional analogue: spreading of a pile of monodisperse oil droplets at a boundary. In our system the droplets are buoyant, adhesive, and in contrast to sand, here friction is negligible. The buoyant droplets are added to the pile one-at-a-time. As the aggregate grows, it reaches a critical height and the 2D pile spreads out across the barrier. We find that, while granularity is important, the growth process is reminiscent of a continuum liquid. We define a ``granular capillary length'', analogous to the capillary length in liquids, which sets the critical height of the aggregate through a balance of buoyancy and adhesion. At a coarse-grained level, the granular capillary length is capable of describing both steady-state characteristics and dynamic properties of the system, while at a granular level repeated collapsing events play a critical role in the formation of the pile.
