SGER: Granular Dynamics and Fluid Mechanics

9974095goldstein这是一个跨学科的理论和实验项目，研究沙子、种子颗粒、微珠、颗粒等颗粒物质中图案的形成。目标是改进现有的装置，使其在由水和玻璃微球组成的非均匀介质中产生波纹和图案。有了这个装置，新的实验可以进行，应该阐明在海滩，沙丘和类似情况下发生的风和水驱动模式的基本问题。该装置是一个环形室，其中水覆盖砂以可控速度剪切。一个大的参数空间是由砂的尺寸和粗糙度、浮力、流体粘度、深度和剪切速率的变化来定义的。不稳定性、模式竞争和长时间动态的延时视频记录将用于量化行为。该项目将为学生提供基础性和实践性的优秀训练。这个跨学科的理论和实验项目将构建一个新的仪器来研究颗粒状物质（如水中的沙子）流动过程中形成的涟漪和图案。尽管在颗粒物质中普遍存在风和水驱动的模式，但这些模式还没有得到很好的理解。新的仪器将允许改变许多重要的参数，如风速、沙密度、剪切力等。视频技术将用于捕捉模式的发展。将对这些模式进行建模和理论分析。该项目将在基础性和实践性的课题上为学生提供良好的训练

9974095GoldsteinThis is an interdisciplinary theory and experiment project that addresses pattern formation in granular matter such as sand, seed grains, micro beads, particles, etc. The objective is to refine an existing apparatus that produces ripples andpatterns in a heterogeneous medium consisting of water and glass micro-spheres. With this apparatus, new experiments can be carried out that should shed light on fundamental issues underlying wind- and water-driven patterns that occur in beaches, sand dunes, and similar situations. The apparatus is an annular chamber in which water overlaying sand is sheared with controllable speed. A large parameter space is defined by variations in size and roughness of the sand, its buoyancy, the fluid viscosity, depth and shear rate. Time-lapse video recording of the instabilities, pattern competition, and long-time dynamics will be used to quantify the behavior. The project will provide excellent training for students in topics of both fundamental and practical significance.%%%This interdisciplinary theory and experiment project will construct a new apparatus to investigate ripples and patterns that form during the flow of granular matter such as sand in water. Despite the ubiquity of wind- and water-driven patterns in granular matter, these patterns are not well understood. The new apparatus will allow the variation of many important parameters, equivalent to wind speed, sand density, shear forces, etc. Video techniques will be used to capture the development of patterns. The patterns will be modeled and theoretically analyzed. The project will provide excellent training for students in topics of both fundamental and practical significance.***