| 项目编号: | 1600292
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| 项目名称: | Bulk Turbulence in Polymer Solutions: Beyond Friction Drag Reduction |
| 作者: | Nicholas Ouellette
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| 承担单位: | Stanford University
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| 批准年: | 2014
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| 开始日期: | 2015-09-01
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| 结束日期: | 2017-08-31
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| 资助金额: | USD210673
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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: | polymer
; additive
; bulk turbulence
; research
; drag
; long-chain polymer
; skin friction
; drag reduction
; polymer solution
; modification
; non-newtonian turbulence
; frictional loss
; skin-friction drag reduction
; polymer concentration
; flow
; total fluid drag
|
| 英文摘要: | PI: Ouellette, Nicholas
Proposal Number: 1436423
The goal of the proposed research is to explore the effects of adding polymers in the bulk of turbulent flows. When small amounts of additives, including long-chain polymers, surfactants, or microbubbles, are added to a turbulent flow, the structure and dynamics of the flow can change dramatically. The most celebrated effect of additives is skin-friction drag reduction: tiny amounts of polymers or surfactants can reduce the drag in a turbulent wall-bounded flow by up to 80%. After years of research, the scientific community is beginning to reach consensus on the fundamental physics of this drag reduction. Skin friction, however, is only a part of the total fluid drag experienced by ships or other objects immersed in a fluid. Separation of the boundary layer and the dynamics of turbulent wakes lead to energy losses that frequently dominate the frictional losses over the object. Understanding how additives affect these other types of drag requires the study of the modification of bulk turbulence, far from any walls, in the presence of additives. Although it is known that bulk turbulence does change with additives, current models cannot explain the experimental observations. The research proposed here will address this gap via detailed experimental measurements of bulk turbulence in polymer solutions. In terms of education and outreach, a new module for an undergraduate laboratory class based on non-Newtonian turbulence, will be developed. In addition, the PI will develop movies about the research results that will be displayed in an on-campus coffee shop and on YouTube, and will participate in K-12 outreach via a local science-fair program.
The primary goal of the project is to understand what aspects of the modification of the turbulent dynamics by polymers is dependent on the presence of a wall, and what aspects are more universal. To address this question, the rates of energy injection, scale-to-scale transfer, and dissipation will be measured as a function of polymer concentration, and modification to the decay of turbulence will be studied. In addition, measurements will be made of the spatial structure of the flow, in order to test the common hypothesis that polymers interact with and suppress small-scale vorticity. The experimental measurements will be made in the Lagrangian framework, using Lagrangian particle tracking, where a multicamera stereoimaging setup is used to follow the motion of small tracer particles in three dimensions and in time as they are advected by the flow. |
| 资源类型: | 项目
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| 标识符: | http://119.78.100.158/handle/2HF3EXSE/93308
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| Appears in Collections: | 影响、适应和脆弱性
气候减缓与适应
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| Recommended Citation: | |
Nicholas Ouellette. Bulk Turbulence in Polymer Solutions: Beyond Friction Drag Reduction. 2014-01-01.
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