Comparison of Velocity and Reynolds Stress Distributions in a Straight Rectangular Channel with Submerged and Emergent Vegetation
Vegetation in rivers and streams plays an important role in preventing erosion and improving bank stability. Comparison between emergent vegetation (bank vegetation) and submerged vegetation, in terms of velocity and Reynolds stress distributions, for the same aspect ratio and flow discharge, has re...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-07-01
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| Series: | Water |
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| Online Access: | https://www.mdpi.com/2073-4441/15/13/2435 |
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| author | Mohammad Reza Tabesh Mofrad Hossein Afzalimehr Parsa Parvizi Sajjad Ahmad |
| author_facet | Mohammad Reza Tabesh Mofrad Hossein Afzalimehr Parsa Parvizi Sajjad Ahmad |
| author_sort | Mohammad Reza Tabesh Mofrad |
| collection | DOAJ |
| description | Vegetation in rivers and streams plays an important role in preventing erosion and improving bank stability. Comparison between emergent vegetation (bank vegetation) and submerged vegetation, in terms of velocity and Reynolds stress distributions, for the same aspect ratio and flow discharge, has received limited attention in the literature. This study investigates the velocity and Reynolds stress, as well as the log law for submerged and emergent vegetation in a laboratory flume and compares the results for a different set up with different sediment size and aspect ratio but the same discharge. The results indicate that the influence of submerged vegetation on the secondary currents generation is less than emergent vegetation. In addition, the log law application is valid for both submerged and emergent vegetation cases, however, it is valid up to y/h = 0.75 for emergent vegetation (in which the vegetation cover in banks is partly out of the water) but up to y/h = 0.25 for vegetation bank. For both submerged and emergent vegetation, Reynolds stress distribution presents a convex form but with a different turning point. Comparison of the results with those in an artificial pool over submerged vegetation and low aspect ratio (<5) keeps almost the same form for velocity and Reynolds stress distributions but decreases the turning point in Reynolds stress distribution. For the submerged vegetation cover, the location of zero shear stress superposes that of maximum velocity, but for the emergent vegetation approaching the bank vegetation and shifting the maximum velocity towards the bed, the location of zero shear stress approaches the bed. |
| first_indexed | 2024-03-11T01:25:12Z |
| format | Article |
| id | doaj.art-2431b7de44144f7c9ff39cfcf461086b |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-03-11T01:25:12Z |
| publishDate | 2023-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-2431b7de44144f7c9ff39cfcf461086b2023-11-18T17:48:13ZengMDPI AGWater2073-44412023-07-011513243510.3390/w15132435Comparison of Velocity and Reynolds Stress Distributions in a Straight Rectangular Channel with Submerged and Emergent VegetationMohammad Reza Tabesh Mofrad0Hossein Afzalimehr1Parsa Parvizi2Sajjad Ahmad3Civil Engineering School, Iran University of Science and Technology, Tehran 16846-13114, IranCivil Engineering School, Iran University of Science and Technology, Tehran 16846-13114, IranWater Engineering Department, Isfahan University of Technology, Isfahan 84156-83111, IranDepartment of Civil and Environmental Engineering and Construction, University of Nevada, Las Vegas, NV 89154, USAVegetation in rivers and streams plays an important role in preventing erosion and improving bank stability. Comparison between emergent vegetation (bank vegetation) and submerged vegetation, in terms of velocity and Reynolds stress distributions, for the same aspect ratio and flow discharge, has received limited attention in the literature. This study investigates the velocity and Reynolds stress, as well as the log law for submerged and emergent vegetation in a laboratory flume and compares the results for a different set up with different sediment size and aspect ratio but the same discharge. The results indicate that the influence of submerged vegetation on the secondary currents generation is less than emergent vegetation. In addition, the log law application is valid for both submerged and emergent vegetation cases, however, it is valid up to y/h = 0.75 for emergent vegetation (in which the vegetation cover in banks is partly out of the water) but up to y/h = 0.25 for vegetation bank. For both submerged and emergent vegetation, Reynolds stress distribution presents a convex form but with a different turning point. Comparison of the results with those in an artificial pool over submerged vegetation and low aspect ratio (<5) keeps almost the same form for velocity and Reynolds stress distributions but decreases the turning point in Reynolds stress distribution. For the submerged vegetation cover, the location of zero shear stress superposes that of maximum velocity, but for the emergent vegetation approaching the bank vegetation and shifting the maximum velocity towards the bed, the location of zero shear stress approaches the bed.https://www.mdpi.com/2073-4441/15/13/2435bank vegetationbed vegetationaspect ratioReynolds stressinflection point |
| spellingShingle | Mohammad Reza Tabesh Mofrad Hossein Afzalimehr Parsa Parvizi Sajjad Ahmad Comparison of Velocity and Reynolds Stress Distributions in a Straight Rectangular Channel with Submerged and Emergent Vegetation Water bank vegetation bed vegetation aspect ratio Reynolds stress inflection point |
| title | Comparison of Velocity and Reynolds Stress Distributions in a Straight Rectangular Channel with Submerged and Emergent Vegetation |
| title_full | Comparison of Velocity and Reynolds Stress Distributions in a Straight Rectangular Channel with Submerged and Emergent Vegetation |
| title_fullStr | Comparison of Velocity and Reynolds Stress Distributions in a Straight Rectangular Channel with Submerged and Emergent Vegetation |
| title_full_unstemmed | Comparison of Velocity and Reynolds Stress Distributions in a Straight Rectangular Channel with Submerged and Emergent Vegetation |
| title_short | Comparison of Velocity and Reynolds Stress Distributions in a Straight Rectangular Channel with Submerged and Emergent Vegetation |
| title_sort | comparison of velocity and reynolds stress distributions in a straight rectangular channel with submerged and emergent vegetation |
| topic | bank vegetation bed vegetation aspect ratio Reynolds stress inflection point |
| url | https://www.mdpi.com/2073-4441/15/13/2435 |
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