Performance of a shallow-water model for simulating flow over trapezoidal broad-crested weirs
Shallow-water models are standard for simulating flow in river systems during floods, including in the near-field of sudden changes in the topography, where vertical flow contraction occurs such as in case of channel overbanking, side spillways or levee overtopping. In the case of stagnant inundatio...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Sciendo
2019-12-01
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| Series: | Journal of Hydrology and Hydromechanics |
| Subjects: | |
| Online Access: | https://doi.org/10.2478/johh-2019-0014 |
| _version_ | 1828949535276138496 |
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| author | Říha Jaromír Duchan David Zachoval Zbyněk Erpicum Sébastien Archambeau Pierre Pirotton Michel Dewals Benjamin |
| author_facet | Říha Jaromír Duchan David Zachoval Zbyněk Erpicum Sébastien Archambeau Pierre Pirotton Michel Dewals Benjamin |
| author_sort | Říha Jaromír |
| collection | DOAJ |
| description | Shallow-water models are standard for simulating flow in river systems during floods, including in the near-field of sudden changes in the topography, where vertical flow contraction occurs such as in case of channel overbanking, side spillways or levee overtopping. In the case of stagnant inundation and for frontal flow, the flow configurations are close to the flow over a broad-crested weir with the trapezoidal profile in the flow direction (i.e. inclined upstream and downstream slopes). In this study, results of shallow-water numerical modelling were compared with seven sets of previous experimental observations of flow over a frontal broad-crested weir, to assess the effect of vertical contraction and surface roughness on the accuracy of the computational results. Three different upstream slopes of the broad-crested weir (V:H = 1:Z1 = 1:1, 1:2, 1:3) and three roughness scenarios were tested. The results indicate that, for smooth surface, numerical simulations overestimate by about 2 to 5% the weir discharge coefficient. In case of a rough surface, the difference between computations and observations reach up to 10%, for high relative roughness. When taking into account mentioned the differences, the shallow-water model may be applied for a range of engineering purposes. |
| first_indexed | 2024-12-14T06:09:11Z |
| format | Article |
| id | doaj.art-aa55d71ce40547149541ea2472500fb9 |
| institution | Directory Open Access Journal |
| issn | 0042-790X |
| language | English |
| last_indexed | 2024-12-14T06:09:11Z |
| publishDate | 2019-12-01 |
| publisher | Sciendo |
| record_format | Article |
| series | Journal of Hydrology and Hydromechanics |
| spelling | doaj.art-aa55d71ce40547149541ea2472500fb92022-12-21T23:14:12ZengSciendoJournal of Hydrology and Hydromechanics0042-790X2019-12-0167432232810.2478/johh-2019-0014Performance of a shallow-water model for simulating flow over trapezoidal broad-crested weirsŘíha Jaromír0Duchan David1Zachoval Zbyněk2Erpicum Sébastien3Archambeau Pierre4Pirotton Michel5Dewals Benjamin6Faculty of Civil Engineering, Brno University of Technology, Brno, Czech Republic.Faculty of Civil Engineering, Brno University of Technology, Brno, Czech Republic.Faculty of Civil Engineering, Brno University of Technology, Brno, Czech Republic.Hydraulics in Environmental and Civil Engineering (HECE), Research unit Urban & Environmental Engineering, University of Liege (ULiège), Belgium.Hydraulics in Environmental and Civil Engineering (HECE), Research unit Urban & Environmental Engineering, University of Liege (ULiège), Belgium.Hydraulics in Environmental and Civil Engineering (HECE), Research unit Urban & Environmental Engineering, University of Liege (ULiège), Belgium.Hydraulics in Environmental and Civil Engineering (HECE), Research unit Urban & Environmental Engineering, University of Liege (ULiège), Belgium.Shallow-water models are standard for simulating flow in river systems during floods, including in the near-field of sudden changes in the topography, where vertical flow contraction occurs such as in case of channel overbanking, side spillways or levee overtopping. In the case of stagnant inundation and for frontal flow, the flow configurations are close to the flow over a broad-crested weir with the trapezoidal profile in the flow direction (i.e. inclined upstream and downstream slopes). In this study, results of shallow-water numerical modelling were compared with seven sets of previous experimental observations of flow over a frontal broad-crested weir, to assess the effect of vertical contraction and surface roughness on the accuracy of the computational results. Three different upstream slopes of the broad-crested weir (V:H = 1:Z1 = 1:1, 1:2, 1:3) and three roughness scenarios were tested. The results indicate that, for smooth surface, numerical simulations overestimate by about 2 to 5% the weir discharge coefficient. In case of a rough surface, the difference between computations and observations reach up to 10%, for high relative roughness. When taking into account mentioned the differences, the shallow-water model may be applied for a range of engineering purposes.https://doi.org/10.2478/johh-2019-0014discharge coefficientfrontal broad-crested weirshallow flow modellingrough weir crest |
| spellingShingle | Říha Jaromír Duchan David Zachoval Zbyněk Erpicum Sébastien Archambeau Pierre Pirotton Michel Dewals Benjamin Performance of a shallow-water model for simulating flow over trapezoidal broad-crested weirs Journal of Hydrology and Hydromechanics discharge coefficient frontal broad-crested weir shallow flow modelling rough weir crest |
| title | Performance of a shallow-water model for simulating flow over trapezoidal broad-crested weirs |
| title_full | Performance of a shallow-water model for simulating flow over trapezoidal broad-crested weirs |
| title_fullStr | Performance of a shallow-water model for simulating flow over trapezoidal broad-crested weirs |
| title_full_unstemmed | Performance of a shallow-water model for simulating flow over trapezoidal broad-crested weirs |
| title_short | Performance of a shallow-water model for simulating flow over trapezoidal broad-crested weirs |
| title_sort | performance of a shallow water model for simulating flow over trapezoidal broad crested weirs |
| topic | discharge coefficient frontal broad-crested weir shallow flow modelling rough weir crest |
| url | https://doi.org/10.2478/johh-2019-0014 |
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