Global S&T Development Trend Analysis Platform of Resources and Environment
DOI | 10.1002/2016WR020090 |
A new model for predicting the drag exerted by vegetation canopies | |
Etminan, Vahid1,2; Lowe, Ryan J.2,3,4; Ghisalberti, Marco1,5 | |
2017-04-01 | |
发表期刊 | WATER RESOURCES RESEARCH |
ISSN | 0043-1397 |
EISSN | 1944-7973 |
出版年 | 2017 |
卷号 | 53期号:4 |
文章类型 | Article |
语种 | 英语 |
国家 | Australia |
英文摘要 | The influence of vegetation canopies on the flow structure in streams, rivers, and floodplains is heavily dependent on the cumulative drag forces exerted by the vegetation. The drag coefficients of vegetation elements within a canopy have been shown to be significantly different from the well-established value for a single element in isolation. This study investigates the mechanisms that determine canopy flow resistance and proposes a new model for predicting canopy drag coefficients. Large Eddy Simulations were used to investigate the fine-scale hydrodynamics within emergent canopies with solid area fractions (k) ranging from 0.016 to 0.25. The influences of three mechanisms in modifying canopy drag, namely, blockage, sheltering, and delayed separation, were investigated. While the effects of sheltering and delayed separation were found to slightly reduce the drag of very sparse canopies, the blockage effect significantly increased the drag of denser canopies (lambda similar to 0.04). An analogy between canopy flow and wall-confined flow around bluff bodies is used to identify an alternative reference velocity in the definition of the canopy drag coefficient; namely, the constricted cross-section velocity (Uc). Through comparison with both prior experimental data and the present numerical simulations, typical formulations for the drag coefficient of a single cylinder are shown to accurately predict the drag coefficient of staggered emergent canopies when Uc is used as the reference velocity. Finally, it is shown that this new model can be extended to predict the bulk drag coefficient of randomly arranged vegetation canopies. |
领域 | 资源环境 |
收录类别 | SCI-E |
WOS记录号 | WOS:000403682600037 |
WOS关键词 | LARGE-EDDY SIMULATION ; THROUGH EMERGENT VEGETATION ; MODERATE REYNOLDS-NUMBER ; CIRCULAR-CYLINDER ; SUBMERGED VEGETATION ; FLOW RESISTANCE ; CHANNEL ; TRANSPORT ; ARRAYS ; COEFFICIENTS |
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/21873 |
专题 | 资源环境科学 |
作者单位 | 1.Univ Western Australia, Sch Civil Environm & Min Engn, Perth, WA, Australia; 2.Univ Western Australia, Sch Earth & Environm, Perth, WA, Australia; 3.Univ Western Australia, UWA Oceans Inst, Perth, WA, Australia; 4.Univ Western Australia, ARC Ctr Excellence Coral Reef Studies, Perth, WA, Australia; 5.Univ Melbourne, Dept Infrastruct Engn, Parkville, Vic, Australia |
推荐引用方式 GB/T 7714 | Etminan, Vahid,Lowe, Ryan J.,Ghisalberti, Marco. A new model for predicting the drag exerted by vegetation canopies[J]. WATER RESOURCES RESEARCH,2017,53(4). |
APA | Etminan, Vahid,Lowe, Ryan J.,&Ghisalberti, Marco.(2017).A new model for predicting the drag exerted by vegetation canopies.WATER RESOURCES RESEARCH,53(4). |
MLA | Etminan, Vahid,et al."A new model for predicting the drag exerted by vegetation canopies".WATER RESOURCES RESEARCH 53.4(2017). |
条目包含的文件 | 条目无相关文件。 |
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