RUI: Elongated Granular Materials: Simulation and Experiment

非技术摘要：沙堆是一个堵塞系统的例子：颗粒不能相互移动，沙堆相对稳定。一堆堆的棒状物比圆形颗粒的刚性大得多。这就提出了一些有趣的物理学问题，比如这两个系统在微观层面上有什么不同，粒子的几何形状在它们的堵塞和流动中起着什么作用？这些问题的答案在石油开采中也有重要的工业应用。这些系统相对来说还没有被探索过。该项目寻求对颗粒形状如何影响堵塞状态的开始和稳定性的新理解。 该项目的重点是开发一个计算和实验框架系统的棒状颗粒材料。模拟结果将与实验进行比较，以揭示现有的普通颗粒材料理论如何随着颗粒的拉长而崩溃。该项目将对本科生进行科学实验和计算方法方面的培训。根据该项目的教育部分，一个只招收本科生的机构联盟将评估本科生物理研究的影响。 调查和焦点小组的结果将使各机构能够有效地拓宽和提供见解，以如何加强本科生的研究经验。技术摘要：细长颗粒堆比圆形颗粒堆刚性大得多，这提出了许多有趣的物理问题，同时对工业应用具有重要影响。该项目侧重于新的计算和实验研究方法，以探测颗粒形状对堵塞状态的影响，作为颗粒纵横比的函数。模拟将结合现实模型的静摩擦-一个关键组成部分的干扰过渡-和结果将进行比较，使用旋转鼓和料斗，测量临界休止角和干扰概率作为粒子的纵横比，材料性能和系统大小/尺寸的函数进行实验。该项目将对本科生进行科学实验和计算方法方面的培训。根据该项目的教育部分，一个只招收本科生的机构联盟将评估本科生物理研究的影响。 调查和焦点小组的结果将使机构能够有效地扩大和提供有关如何加强本科生研究经验的见解。

NONTECHNICAL ABSTRACT: A sandpile is an example of a jammed system: the grains cannot move around one another and the pile is relatively stable. Piles of rods are significantly more rigid than those of round particles. This raises intriguing physics questions, such are what is the difference in the two systems at the microscopic level and what role does the geometrical shape of particles play in their jamming and flow? Answers to these questions also have important industrial applications in oil recovery. These systems haev remained relatively unexplored. This project seeks a new understanding of how particle shape influences the onset and stability of the jammed state. This project focuses on the development of a computational and experimental framework for systems of rod-like granular materials. Results of simulations will be compared with experiments to reveal how existing theories of ordinary granular materials break down as particles become elongated. The project will train undergraduate students in scientific experimental and computational methods. Under the education component of the project, a coalition of undergraduate-only institutions will assess the impact of undergraduate physics research. Results from surveys and focus groups will enable institutions to effectively broaden and provide insights in to how to strengthen the undergraduate research experience.TECHNICAL ABSTRACT: Piles of elongated granular particles are significantly more rigid than those of round particles, presenting a number of intriguing physics questions, as well as having important consequences for industrial applications. This project focuses on new computational and experimental research methods to probe the effects of the particle shape on the jammed state as a function of particle aspect ratio. Simulations will incorporate realistic models for static friction --- a critical component of the jamming transition --- and the results will be compared with experiments performed using rotating drums and hoppers that measure critical angles of repose and jamming probability as functions of particle aspect ratio, material properties, and system size/dimension. The project will train undergraduate students in scientific experimental and computational methods. Under the education component of the project, a coalition of undergraduate-only institutions will assess the impact of undergraduate physics research. Results from surveys and focus groups will enable institutions to effectively broaden and provide insights in to how to strengthen the undergraduate research experience.