| 项目编号: | 1605283
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| 项目名称: | Collaborative Research: Discontinuous Shear Thickening and Shear Jamming in Dense Suspensions: Statistical Mechanics and the Microscopic Basis for Extreme Transitions of Properties |
| 作者: | Jeffrey Morris
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| 承担单位: | CUNY City College
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| 批准年: | 2016
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| 开始日期: | 2016-07-01
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| 结束日期: | 2019-06-30
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| 资助金额: | 236758
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| 资助来源: | US-NSF
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| 项目类别: | Standard Grant
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| 国家: | US
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| 语种: | 英语
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| 特色学科分类: | Engineering - Chemical, Bioengineering, Environmental, and Transport Systems
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| 英文关键词: | dst
; discontinuous shear
; shear rate
; project
; dense suspension
; bulbulthis collaborative project
; flow
; shear jamming
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| 英文摘要: | CBET - 1605283/1605428
PI: Morris, Jeffrey F./Chakraborty, Bulbul
This collaborative project comprises computational and theoretical studies of the flow of suspensions consisting of solid particles in liquids. The project focuses on concentrated suspensions, where particles occupy more than half of the mixture volume. These are often called dense suspensions, and they are found in application as cement, concrete, and mineral ore slurries. Dense suspensions can change properties suddenly when flow conditions change. In some cases, as the strength of the flow, or shear rate, increases, the mixture can suddenly exhibit an extremely large increase in flow resistance, a phenomenon known as "discontinuous shear thickening" (DST). The flow can even stop, which is known as "shear jamming." DST can have major negative effects on industrial processes involving the mixtures. While DST has been known for many years, it has not been explained. The goal of this project is to determine why this phenomenon happens, which could provide guidance how to design suspensions and processing operations to diminish negative effects of DST. Results of the research will be used in modules that will enable high school students to visualize how many-particle systems result in large-scale behavior, such as DST in cornstarch suspensions, where small grains of starch cause enormous changes in flow properties.
The project will explore recent observations that DST can be explained by particle contacts and friction. The work will explore the structure of networks of forces between the particles and how this structure changes as the flow rate is increased to a level causing abrupt changes in properties. In particular, the team will explore whether the flow property transition has the characteristics of a phase transition through simulations of discrete particles in different flows and applications of theoretical concepts from statistical physics. The role of the liquid will be considered by comparing results with the behavior of dry granular systems in which the force network concept and its relation to jamming have been examined by others. This work will probe the relationship of flow-induced property changes to thermodynamic phase transitions and will establish the similarities and differences between different particulate flows. Because solid-liquid mixtures are commonly used in industry and are found in geophysical settings such as mud flows, the project will significantly expand our ability to understand and ultimately predict the dynamics of these complicated systems in important applications. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/91856
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| Appears in Collections: | 全球变化的国际研究计划
科学计划与规划
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| Recommended Citation: | |
Jeffrey Morris. Collaborative Research: Discontinuous Shear Thickening and Shear Jamming in Dense Suspensions: Statistical Mechanics and the Microscopic Basis for Extreme Transitions of Properties. 2016-01-01.
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