Research Member
Research Department
Research Date
Research Year
2024
Research Journal
Water Science
Research Publisher
Taylor and Francis
Research Vol
38
Research Rank
Q2
Research_Pages
140-157
Research Website
https://doi.org/10.1080/23570008.2024.2307223
Research Abstract
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
Research Rank
International Journal