RUI: Elongated Granular Materials: Simulation and Experiment

Rochester Institute Of Tech, Rochester NY

Investigators

Abstract

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.