SGER: Granular Dynamics and Fluid Mechanics

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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.***