CAREER: Instabilities in the Flow of Dry and Wet Granular Matter

9983659这个CAREER项目将通过实验研究粘性和非粘性颗粒物质在各种激发和边界条件下流动的不稳定性，这些条件会导致颗粒流动，模式或分离。没有基本的理论方法，颗粒物质类似的Navier-Stokes方程的流体。一个重要的阻碍发展的全面理论一直缺乏定量实验的颗粒物质。使用筒仓系统和库埃特剪切流动池的拟议研究的结果将产生新开发的流体动力学方法的适用性范围的关键测试，特别是在最近的数值工作，其中显示了一个明确的故障流体动力学甚至名义耗散，并提出了其他连续方法的适用性问题。一个新的实验室为基础的课程将开发在自然界中的非线性现象作为本科物理课程和暑期高中教师培训计划的一部分。%这个凝聚态物理的CAREER项目是干和湿颗粒物质的性质的实验研究。颗粒物质，如沙子或谷物，在许多工程过程和地质现象中很重要，但对其性质还没有令人满意的描述。使用高速和高分辨率成像的拟议实验将检查各种几何形状的颗粒材料，以确定它们在外部能量增加机制下的特性。从拟议的实验中获得的基本认识将最终导致对一系列现象的更好理解，例如在滑坡中引起长时间径流的条件，以及漏斗流中颗粒的分离。一个新的实验室为基础的课程，称为“自然模式”将开发作为本科物理课程和夏季高中教师培训计划的一部分。实验的写作和设计将在网上提供，以弥补目前非线性物理教科书的不足，重点是做实验。

9983659This CAREER project will investigate experimentally the instabilities in the flow of cohesive and non-cohesive granular matter under a variety of excitations and boundary conditions that lead to granular flows, patterns, or segregation. There is no fundamental theoretical approach for granular matter similar to the Navier--Stokes equations for fluids. An important deterrent to the development of a comprehensive theory has been lack of quantitative experiments on granular matter. The results of the proposed studies using silo systems, and couette shear flow cells will yield critical tests of the range of applicability of newly developed hydrodynamic approaches, especially in light of recent numerical work which shows a clear breakdown of hydrodynamics for even nominal dissipation and raises questions about the applicability of other continuum approaches. A new laboratory-based course will be developed on nonlinear phenomena in nature as part of the undergraduate physics curriculum and a summer high school teacher training program.%%%This condensed matter physics CAREER project is an experimental study of the properties of dry and wet granular matter. Granular matter, like sand or grain, is important in many engineering processes and geological phenomena, but a satisfactory description of its properties does not exist. The proposed experiments using high speed and high resolution imaging will examine granular materials in various geometries to determine their properties under external mechanisms of adding energy. The basic understanding gained from the proposed experiments will ultimately lead to a better understanding of a range of phenomena such as conditions that give rise to long run-offs in landslides, and segregation of grains in hopper flows. A new laboratory-based course called "Patterns in Nature" will be developed as part of the undergraduate physics curriculum and a summer high school teacher training program. The write-ups and the designs for the experiments will be made available on the Web to offset the current lack in textbooks in nonlinear physics with emphasis on doing experiments.***