Flow behavior over well-escape weirs

Weirs play an important role in controlling and managing water in irrigation canal networks through several functions, such as discharge measurements, water distribution, and lowering the water level. Weirs also play a crucial role in protecting canals from flooding, which might cause the earthen ba...

Full description

Bibliographic Details
Main Authors: Hassan I. Mohamed, Gamal Abozeid, Nashat A. Ali, Wagdy M. Saied
Format: Article
Language:English
Published: Taylor & Francis Group 2024-12-01
Series:Water Science
Subjects:
Online Access:https://www.tandfonline.com/doi/10.1080/23570008.2024.2307223
_version_ 1826936202712842240
author Hassan I. Mohamed
Gamal Abozeid
Nashat A. Ali
Wagdy M. Saied
author_facet Hassan I. Mohamed
Gamal Abozeid
Nashat A. Ali
Wagdy M. Saied
author_sort Hassan I. Mohamed
collection DOAJ
description Weirs play an important role in controlling and managing water in irrigation canal networks through several functions, such as discharge measurements, water distribution, and lowering the water level. Weirs also play a crucial role in protecting canals from flooding, which might cause the earthen banks to collapse, by eliminating surplus water at the ends of the canals. Over the previous decades, the flow over the traditional sharp-crested weirs was extensively investigated by many researchers; however, the well-escape weirs have not received sufficient attention. These types of weirs were mostly constructed in the form of vertical wells that may be circular or rectangular in shape, and water may flow through the entire perimeter of the weir or part of the perimeter. In the present research, the effect of the well-escape-weir shape on the characteristics of flow over the weir was studied. A set of models were constructed in different shapes, circular and square, and the entire perimeter of the weir or part of the perimeter is working as the weir crest length. The discharge passing over the unit length of the weir crest (q) is investigated and compared for the circular and square weirs of various crest lengths and positions. The results indicated that the discharge capacity of the circular weirs increases by a rate ranging between 7.5% and 15% more than that of the square weirs at the same head. Also, results indicated that the discharge coefficient of the circular weirs increases by a rate ranging between 9.3% and 10.3% more than that of the square weirs. This behavior can be attributed to the interference between the orthogonal water nappes at the corners of the square models. In addition, the flow direction has little effect on the discharge coefficient at small discharges, and this effect becomes more obvious at higher discharges. Additionally, the well-escape weirs of the upstream crest have a slightly higher discharge capacity than those of the downstream crest due to the effect of the approach velocity, which increases the water entrance velocity at the upstream crest. The results of flow patterns around the weir showed that the locations of maximum flow velocities (u, v, w) are mostly near the weir crest and depend entirely on the crest length and position.
first_indexed 2024-03-08T05:15:42Z
format Article
id doaj.art-0213b5043b444d79970d953556896d28
institution Directory Open Access Journal
issn 2357-0008
language English
last_indexed 2025-02-17T18:18:00Z
publishDate 2024-12-01
publisher Taylor & Francis Group
record_format Article
series Water Science
spelling doaj.art-0213b5043b444d79970d953556896d282024-12-13T08:34:54ZengTaylor & Francis GroupWater Science2357-00082024-12-0138114015710.1080/23570008.2024.2307223Flow behavior over well-escape weirsHassan I. Mohamed0Gamal Abozeid1Nashat A. Ali2Wagdy M. Saied3Civil Engineering Department, Faculty of Engineering, Assuit University, Assiut, EgyptCivil Engineering Department, Faculty of Engineering, Assuit University, Assiut, EgyptCivil Engineering Department, Faculty of Engineering, Assuit University, Assiut, EgyptCivil Engineering Department, Faculty of Engineering, Assuit University, Assiut, EgyptWeirs play an important role in controlling and managing water in irrigation canal networks through several functions, such as discharge measurements, water distribution, and lowering the water level. Weirs also play a crucial role in protecting canals from flooding, which might cause the earthen banks to collapse, by eliminating surplus water at the ends of the canals. Over the previous decades, the flow over the traditional sharp-crested weirs was extensively investigated by many researchers; however, the well-escape weirs have not received sufficient attention. These types of weirs were mostly constructed in the form of vertical wells that may be circular or rectangular in shape, and water may flow through the entire perimeter of the weir or part of the perimeter. In the present research, the effect of the well-escape-weir shape on the characteristics of flow over the weir was studied. A set of models were constructed in different shapes, circular and square, and the entire perimeter of the weir or part of the perimeter is working as the weir crest length. The discharge passing over the unit length of the weir crest (q) is investigated and compared for the circular and square weirs of various crest lengths and positions. The results indicated that the discharge capacity of the circular weirs increases by a rate ranging between 7.5% and 15% more than that of the square weirs at the same head. Also, results indicated that the discharge coefficient of the circular weirs increases by a rate ranging between 9.3% and 10.3% more than that of the square weirs. This behavior can be attributed to the interference between the orthogonal water nappes at the corners of the square models. In addition, the flow direction has little effect on the discharge coefficient at small discharges, and this effect becomes more obvious at higher discharges. Additionally, the well-escape weirs of the upstream crest have a slightly higher discharge capacity than those of the downstream crest due to the effect of the approach velocity, which increases the water entrance velocity at the upstream crest. The results of flow patterns around the weir showed that the locations of maximum flow velocities (u, v, w) are mostly near the weir crest and depend entirely on the crest length and position.https://www.tandfonline.com/doi/10.1080/23570008.2024.2307223Dischargedischarge coefficientfloodingsharp-crested weirswell-escape weir
spellingShingle Hassan I. Mohamed
Gamal Abozeid
Nashat A. Ali
Wagdy M. Saied
Flow behavior over well-escape weirs
Water Science
Discharge
discharge coefficient
flooding
sharp-crested weirs
well-escape weir
title Flow behavior over well-escape weirs
title_full Flow behavior over well-escape weirs
title_fullStr Flow behavior over well-escape weirs
title_full_unstemmed Flow behavior over well-escape weirs
title_short Flow behavior over well-escape weirs
title_sort flow behavior over well escape weirs
topic Discharge
discharge coefficient
flooding
sharp-crested weirs
well-escape weir
url https://www.tandfonline.com/doi/10.1080/23570008.2024.2307223
work_keys_str_mv AT hassanimohamed flowbehavioroverwellescapeweirs
AT gamalabozeid flowbehavioroverwellescapeweirs
AT nashataali flowbehavioroverwellescapeweirs
AT wagdymsaied flowbehavioroverwellescapeweirs