标题： 摩擦在悬浮粗糙颗粒之间的水动力起源 显示英文标题

标题： Hydrodynamic Origin of Friction Between Suspended Rough Particles

摘要： 颗粒之间的切向相互作用在悬浮流变学中起着核心作用。 我们从理论上表明，这些相互作用通常归因于接触摩擦，实际上是由于相对运动的粗糙颗粒之间的流体流动直接导致的。 我们发现，微小的表面不平度通常会导致局部的水动力滑动力和力矩，其大小可以比光滑颗粒的情况大几个数量级。 一种完全解析的薄膜理论表明，这些力随着表面分离距离的减小而增大，其奇异程度远高于光滑颗粒的对数尺度。 这种即将出现的奇异性严格限制了颗粒的旋转与其平动之间的关系，恢复了密集悬浮流变学中的一个关键因素。 尽管这些特性纯粹源于水动力学，但它们却与干滚动和滑动摩擦的几个方面相似。 显示英文摘要

摘要： Tangential interactions between particles play a central role in suspension rheology. We show theoretically that these interactions, often attributed to contact friction, are a direct consequence of fluid flows between rough particles in relative motion. We find that small surface asperities generically lead to localized hydrodynamic sliding forces and torques that can exceed their smooth counterparts by orders of magnitude. A fully analytic thin-film theory shows that these forces grow inversely with the surface separation, significantly more singular than the logarithmic scaling for smooth particles. The impending singularity tightly constrains the particles' rotation with their translation, recovering a crucial ingredient in dense suspension rheology. Despite their purely hydrodynamic origin, these features resemble several aspects of dry rolling and sliding friction.