Collaborative Research: Enhanced Flow and Shear of Irregular Grains and Powders

合作研究：不规则颗粒和粉末的增强流动和剪切

基本信息

批准号：
1435861
负责人：
Stephen Teitel
金额：
$ 11.5万
依托单位：
University of Rochester
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2014
资助国家：
美国
起止时间：
2014-09-01 至 2017-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1435861&HistoricalAwards=false
关键词：
Collaborative Research Enhanced Flow Shear

项目摘要

CBET 1438077/1435861This award supports experimental and computational studies of the flow of granular materials composed of mixtures of particles. The project will investigate the surprising observation that adding a small number of needle-like particles in a granular material composed of spherical particles significantly increases the ability of the material to flow. For very small particles, the investigators hypothesize that the needles and spheres stick together in a way that results in an effective particle shape and size that enables the material to flow more easily. For larger particles less likely to adhere, other lubrication mechanisms are suspected. A series of experiments will be conducted to show how the particle size and the mixture ratio affects flow characteristics. The experiments will be complemented by numerical simulations that can predict the arrangements of particles and correlate particle arrangements with flow behavior in well-defined model flows. The project will provide an environment for graduate and undergraduate students to participate in the research.This project studies the flow and shear of mixtures of particles consisting of spherical and irregularly-shaped particles. Experiments will be conducted with canonical geometries, such as hoppers, cylindrical column collapse, and annular-Couette shear, to study the flow behavior as functions of particles size and mixture ratio. The experiments will tie together several quantities currently used to quantify flow, including the static and dynamic angles of repose, dynamic deflection modulus and flowability index. Computer simulations will study shear in dense systems of rods and mixtures of rods and spheres to reveal the fundamental mechanisms for enhanced flow whether it is changes in the effective morphology or segregation-induced lubrication.

CBET 1438077/1435861这项奖项支持由颗粒混合物组成的颗粒材料流动的实验和计算研究。该项目将调查令人惊讶的观察结果，即在由球形颗粒组成的颗粒材料中添加少量的针状颗粒会显着提高材料流动的能力。对于非常小的颗粒，研究人员假设针和球体以一种有效的颗粒形状和大小的方式粘在一起，从而使材料更容易流动。对于较小的颗粒粘附的可能性较小，怀疑其他润滑机制。将进行一系列实验，以显示粒度和混合比率如何影响流动特性。实验将通过数值模拟来补充，这些模拟可以预测颗粒的排列并将粒子排列与定义明确的模型流中的流动行为相关联。该项目将为研究生和本科生参与研究提供一个环境。该项目研究了由球形和不规则形状的颗粒组成的颗粒混合物的流量和剪切。实验将使用典型的几何形状进行，例如料斗，圆柱形柱塌陷和环形剪切，以研究流动行为作为颗粒大小和混合比率的功能。实验将将目前用于量化流动的几量数，包括休息的静态和动态角度，动态偏转模量和流动性指数。计算机模拟将研究杆和球体混合物的密集系统中的剪切，以揭示有效的形态或隔离诱导的润滑的基本机制，以增强流量的基本机制。