Numerical analysis of sediment transport and depth averaged flow velocity in non-prismatic compound channels
The flow velocity in compound open channels is greatly affected by the geometry of both the main channel (MC) and floodplain (FP). In this study, a numerical investigation of the joint effect between the FP divergence angle and the size of suspended sediment particles on sediment transport and flow...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2023-12-01
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| Series: | Ain Shams Engineering Journal |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2090447923001181 |
| _version_ | 1827578788099129344 |
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| author | Tarek Selim Mahmoud Hesham Mohamed Elkiki Mohamed M. Elsakka |
| author_facet | Tarek Selim Mahmoud Hesham Mohamed Elkiki Mohamed M. Elsakka |
| author_sort | Tarek Selim |
| collection | DOAJ |
| description | The flow velocity in compound open channels is greatly affected by the geometry of both the main channel (MC) and floodplain (FP). In this study, a numerical investigation of the joint effect between the FP divergence angle and the size of suspended sediment particles on sediment transport and flow depth-averaged velocity (DAV) in non-prismatic diverging compound channels was conducted. In addition, the influence of relative flow depth on the DAV in different flow directions (i.e., stream-wise and span-wise) was examined. Three divergence angles of 4.0, 6.3 and 11.3°, four sediment particle sizes of 1, 5, 50 and 500 µm and two relative depths of the FP with respect to the MC of 0.20 and 0.40 were considered during simulations. A Computational Fluid Dynamics (CFD) software ANSYS-Fluent was used to perform the required simulation scenarios and the DAV was expressed in terms of a dimensionless velocity (i.e., relative depth-averaged velocity; RDAV) to generalize the use of the obtained results. Results revealed that the span-wise RDAV gradient between the MC and FP at the middle and the end sections of the divergence reach is much larger in the case of higher divergence angle. Moreover, the presence of coarse sediment particles in the sediment-laden flow resulted in an augmentation in the fluctuations of span-wise and stream-wise RDAVs as compared to those obtained in the case of fine sediment particles. Results also showed that the span-wise RDAV gradient between the two subsections (MC and FP) increases with decreasing the relative flow depth. Sediment particle size had a considerable impact on the span-wise RDAV values, especially in the case of lower relative depth. As the sediment particle size increases, the distortion in the span-wise RDAV distribution curves increases. However, the stream-wise RDAV along the MC and FP decreases, as the sediment particle size decreases, especially in the case of higher relative depth. Based on the results, it can be concluded that the span-wise DAV gradient was greatly affected by the FP divergence angle and sediment particle size. The fluctuations in the span-wise DAV gradient were more pronounced in the case of higher divergence angles and coarser sediment particles. The stream-wise DAV distribution along the MC and FP was mainly influenced by the relative depth and sediment particle size. The stream-wise DAV dip along the MC and FP was more explicit in the case of higher relative depths and finer sediment particles. |
| first_indexed | 2024-03-08T21:51:28Z |
| format | Article |
| id | doaj.art-d2910c14017e40b6815e941710299597 |
| institution | Directory Open Access Journal |
| issn | 2090-4479 |
| language | English |
| last_indexed | 2024-03-08T21:51:28Z |
| publishDate | 2023-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Ain Shams Engineering Journal |
| spelling | doaj.art-d2910c14017e40b6815e9417102995972023-12-20T07:34:09ZengElsevierAin Shams Engineering Journal2090-44792023-12-011412102229Numerical analysis of sediment transport and depth averaged flow velocity in non-prismatic compound channelsTarek Selim0Mahmoud Hesham1Mohamed Elkiki2Mohamed M. Elsakka3Civil Engineering Department, Faculty of Engineering, Port Said University, Port Said 42523, Egypt; Corresponding author.Civil Engineering Department, Faculty of Engineering, Port Said University, Port Said 42523, EgyptCivil Engineering Department, Faculty of Engineering, Port Said University, Port Said 42523, Egypt; Civil Engineering Department, Higher Institute for Engineering and Technology, New Damietta, EgyptMechanical Power Engineering Department, Faculty of Engineering, Port Said University, Port Said 42523, EgyptThe flow velocity in compound open channels is greatly affected by the geometry of both the main channel (MC) and floodplain (FP). In this study, a numerical investigation of the joint effect between the FP divergence angle and the size of suspended sediment particles on sediment transport and flow depth-averaged velocity (DAV) in non-prismatic diverging compound channels was conducted. In addition, the influence of relative flow depth on the DAV in different flow directions (i.e., stream-wise and span-wise) was examined. Three divergence angles of 4.0, 6.3 and 11.3°, four sediment particle sizes of 1, 5, 50 and 500 µm and two relative depths of the FP with respect to the MC of 0.20 and 0.40 were considered during simulations. A Computational Fluid Dynamics (CFD) software ANSYS-Fluent was used to perform the required simulation scenarios and the DAV was expressed in terms of a dimensionless velocity (i.e., relative depth-averaged velocity; RDAV) to generalize the use of the obtained results. Results revealed that the span-wise RDAV gradient between the MC and FP at the middle and the end sections of the divergence reach is much larger in the case of higher divergence angle. Moreover, the presence of coarse sediment particles in the sediment-laden flow resulted in an augmentation in the fluctuations of span-wise and stream-wise RDAVs as compared to those obtained in the case of fine sediment particles. Results also showed that the span-wise RDAV gradient between the two subsections (MC and FP) increases with decreasing the relative flow depth. Sediment particle size had a considerable impact on the span-wise RDAV values, especially in the case of lower relative depth. As the sediment particle size increases, the distortion in the span-wise RDAV distribution curves increases. However, the stream-wise RDAV along the MC and FP decreases, as the sediment particle size decreases, especially in the case of higher relative depth. Based on the results, it can be concluded that the span-wise DAV gradient was greatly affected by the FP divergence angle and sediment particle size. The fluctuations in the span-wise DAV gradient were more pronounced in the case of higher divergence angles and coarser sediment particles. The stream-wise DAV distribution along the MC and FP was mainly influenced by the relative depth and sediment particle size. The stream-wise DAV dip along the MC and FP was more explicit in the case of higher relative depths and finer sediment particles.http://www.sciencedirect.com/science/article/pii/S2090447923001181Divergence angleSuspended sediment particlesRelative depth-averaged velocity (RDAV)Diverging compound channelsComputational Fluid Dynamics (CFD) |
| spellingShingle | Tarek Selim Mahmoud Hesham Mohamed Elkiki Mohamed M. Elsakka Numerical analysis of sediment transport and depth averaged flow velocity in non-prismatic compound channels Ain Shams Engineering Journal Divergence angle Suspended sediment particles Relative depth-averaged velocity (RDAV) Diverging compound channels Computational Fluid Dynamics (CFD) |
| title | Numerical analysis of sediment transport and depth averaged flow velocity in non-prismatic compound channels |
| title_full | Numerical analysis of sediment transport and depth averaged flow velocity in non-prismatic compound channels |
| title_fullStr | Numerical analysis of sediment transport and depth averaged flow velocity in non-prismatic compound channels |
| title_full_unstemmed | Numerical analysis of sediment transport and depth averaged flow velocity in non-prismatic compound channels |
| title_short | Numerical analysis of sediment transport and depth averaged flow velocity in non-prismatic compound channels |
| title_sort | numerical analysis of sediment transport and depth averaged flow velocity in non prismatic compound channels |
| topic | Divergence angle Suspended sediment particles Relative depth-averaged velocity (RDAV) Diverging compound channels Computational Fluid Dynamics (CFD) |
| url | http://www.sciencedirect.com/science/article/pii/S2090447923001181 |
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