Large eddy simulation of flow and scalar transport in a vegetated channel
Predicting flow and mass transport in vegetated regions has a broad range of applications in ecology and engineering practice. This paper presents large eddy simulation (LES) of turbulent flow and scalar transport within a fully developed open-channel with submerged vegetation. To properly represent...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Springer Netherlands
2017
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| Online Access: | http://hdl.handle.net/1721.1/109771 |
| _version_ | 1826189252870799360 |
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| author | Yan, Chao Huang, Wei-Xi Cui, Gui-Xiang Nepf, Heidi |
| author2 | Massachusetts Institute of Technology. Department of Civil and Environmental Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Civil and Environmental Engineering Yan, Chao Huang, Wei-Xi Cui, Gui-Xiang Nepf, Heidi |
| author_sort | Yan, Chao |
| collection | MIT |
| description | Predicting flow and mass transport in vegetated regions has a broad range of applications in ecology and engineering practice. This paper presents large eddy simulation (LES) of turbulent flow and scalar transport within a fully developed open-channel with submerged vegetation. To properly represent the scalar transport, an additional diffusivity was introduced within the canopy to account for the contribution of stem wakes, which were not resolved by the LES, to turbulent diffusion. The LES produced good agreement with the velocity and concentration fields measured in a flume experiment. The simulation revealed a secondary flow distributed symmetrically about the channel centerline, which differed significantly from the circulation in a bare channel. The secondary circulation accelerated the vertical spread of the plume both within and above the canopy layer. Quadrant analysis was used to identify the form and shape of canopy-scale turbulent structures within and above the vegetation canopy. Within the canopy, sweep events contributed more to momentum transfer than ejection events, whereas the opposite occurred above the canopy. The coherent structures were similar to those observed in terrestrial canopies, but smaller in scale due to the constraint of the water surface. |
| first_indexed | 2024-09-23T08:12:12Z |
| format | Article |
| id | mit-1721.1/109771 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T08:12:12Z |
| publishDate | 2017 |
| publisher | Springer Netherlands |
| record_format | dspace |
| spelling | mit-1721.1/1097712022-09-30T08:16:22Z Large eddy simulation of flow and scalar transport in a vegetated channel Yan, Chao Huang, Wei-Xi Cui, Gui-Xiang Nepf, Heidi Massachusetts Institute of Technology. Department of Civil and Environmental Engineering Nepf, Heidi Predicting flow and mass transport in vegetated regions has a broad range of applications in ecology and engineering practice. This paper presents large eddy simulation (LES) of turbulent flow and scalar transport within a fully developed open-channel with submerged vegetation. To properly represent the scalar transport, an additional diffusivity was introduced within the canopy to account for the contribution of stem wakes, which were not resolved by the LES, to turbulent diffusion. The LES produced good agreement with the velocity and concentration fields measured in a flume experiment. The simulation revealed a secondary flow distributed symmetrically about the channel centerline, which differed significantly from the circulation in a bare channel. The secondary circulation accelerated the vertical spread of the plume both within and above the canopy layer. Quadrant analysis was used to identify the form and shape of canopy-scale turbulent structures within and above the vegetation canopy. Within the canopy, sweep events contributed more to momentum transfer than ejection events, whereas the opposite occurred above the canopy. The coherent structures were similar to those observed in terrestrial canopies, but smaller in scale due to the constraint of the water surface. National Science Foundation (U.S.) (Grant AGS-1005480) 2017-06-09T17:08:39Z 2017-10-01T05:00:06Z 2016-12 2017-05-09T07:16:12Z Article http://purl.org/eprint/type/JournalArticle 1567-7419 1573-1510 http://hdl.handle.net/1721.1/109771 Yan, Chao et al. “Large Eddy Simulation of Flow and Scalar Transport in a Vegetated Channel.” Environmental Fluid Mechanics 17.3 (2017): 497–519. en http://dx.doi.org/10.1007/s10652-016-9503-y Environmental Fluid Mechanics Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ Springer Science+Business Media Dordrecht application/pdf Springer Netherlands Springer Netherlands |
| spellingShingle | Yan, Chao Huang, Wei-Xi Cui, Gui-Xiang Nepf, Heidi Large eddy simulation of flow and scalar transport in a vegetated channel |
| title | Large eddy simulation of flow and scalar transport in a vegetated channel |
| title_full | Large eddy simulation of flow and scalar transport in a vegetated channel |
| title_fullStr | Large eddy simulation of flow and scalar transport in a vegetated channel |
| title_full_unstemmed | Large eddy simulation of flow and scalar transport in a vegetated channel |
| title_short | Large eddy simulation of flow and scalar transport in a vegetated channel |
| title_sort | large eddy simulation of flow and scalar transport in a vegetated channel |
| url | http://hdl.handle.net/1721.1/109771 |
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