Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1029/2017WR022292 |
Stratification Effects on Flow Hydrodynamics and Mixing at a Confluence With a Highly Discordant Bed and a Relatively Low Velocity Ratio | |
Cheng, Zhengyang1,2,3; Constantinescu, George1,2 | |
2018-07-01 | |
发表期刊 | WATER RESOURCES RESEARCH |
ISSN | 0043-1397 |
EISSN | 1944-7973 |
出版年 | 2018 |
卷号 | 54期号:7页码:4537-4562 |
文章类型 | Article |
语种 | 英语 |
国家 | USA |
英文摘要 | The effects of temperature induced stratification on flow hydrodynamics, thermal mixing, and the capacity of the flow to entrain sediment at a medium-size stream confluence with a highly discordant bed are investigated. To isolate the effects due to differences in the temperature/density of the incoming streams, two simulations were conducted with identical flow conditions (mean velocity ratio = 0.41 and temperature difference between the two streams Delta T = 4.7 degrees C). In the first case the Richardson number was Ri = 0 (no coupling between the temperature and the momentum equations via the Boussinesq approximation), while in the second simulation Ri = 0.67. Even in the Ri = 0 case the structure of the mixing interface (MI) was different from the one expected for concordant bed confluences with a similar confluence angle and velocity ratio. The MI contained only corotating eddies shed in the shear layer forming on the fast-speed side of the confluence apex. In the Ri = 0.67 case no wake region was present but a large recirculation eddy formed not far from the confluence apex. In both cases, the flow near the upstream part of the MI was found to be highly 3-D and to allow the passage of particles from one side of the confluence to the other. While in the Ri = 0 case mixing was driven by the MI eddies, in the Ri = 0.67 case mixing was controlled by large near-bed intrusions of heavier fluid from the tributary containing colder water and also by the fluid advected in and out of the recirculation eddy. |
英文关键词 | river confluences vortices mixing layers turbulent mixing stratification effects |
领域 | 资源环境 |
收录类别 | SCI-E |
WOS记录号 | WOS:000442502100021 |
WOS关键词 | SEDIMENT EROSION MECHANISMS ; OPEN-CHANNEL BEND ; 2 LARGE RIVERS ; STREAM CONFLUENCE ; PLANFORM GEOMETRY ; STRONG CURVATURE ; CONCORDANT BED ; TURBULENT-FLOW ; MORPHOLOGY ; TRANSPORT |
WOS类目 | Environmental Sciences ; Limnology ; Water Resources |
WOS研究方向 | Environmental Sciences & Ecology ; Marine & Freshwater Biology ; Water Resources |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/21326 |
专题 | 资源环境科学 |
作者单位 | 1.Univ Iowa, Dept Civil & Environm Engn, Iowa City, IA 52242 USA; 2.Univ Iowa, IIHR Hydrosci & Engn, Iowa City, IA 52242 USA; 3.Hydrol Res Ctr, San Diego, CA USA |
推荐引用方式 GB/T 7714 | Cheng, Zhengyang,Constantinescu, George. Stratification Effects on Flow Hydrodynamics and Mixing at a Confluence With a Highly Discordant Bed and a Relatively Low Velocity Ratio[J]. WATER RESOURCES RESEARCH,2018,54(7):4537-4562. |
APA | Cheng, Zhengyang,&Constantinescu, George.(2018).Stratification Effects on Flow Hydrodynamics and Mixing at a Confluence With a Highly Discordant Bed and a Relatively Low Velocity Ratio.WATER RESOURCES RESEARCH,54(7),4537-4562. |
MLA | Cheng, Zhengyang,et al."Stratification Effects on Flow Hydrodynamics and Mixing at a Confluence With a Highly Discordant Bed and a Relatively Low Velocity Ratio".WATER RESOURCES RESEARCH 54.7(2018):4537-4562. |
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