Weirs are utilized for measuring of discharge, diminishing the water slope in canals and
dissemination of water between canals for irrigation, etc. Classical sharp crested weir is associated
with increases in turbulence and bed problems in downstream resulting in scouring activity that is
considered one of unfavorable processes which dangers the general steadiness of the weir. Sharp
crested weir with orifices along these lines introduces the same functions of the classical type but
with has the capacity for minimizing changes in downstream bed configurations. An experimental
study was conducted to predict and evaluate the geometry of bed configurations downstream of a
sharp crested weir equipped with rounded orifices. Ninety nine (99) experimental runs were
conducted. 11 weir models, 3 discharges, and 3 tail water depths. The utilized models referred to
11 scenarios for orifices schedules presented in terms of numbers and locations. 9 symmetrical
orifices, 3 cm distance across each were made in the utilized weir to pass on much water in the
downstream heading. The orifices were orchestrated in 3 equals spaced rows and 3 equal spaced
columns. The study reach secured 4m length downstream the weir. Results were analyzed and
graphically displayed. The geometry of bed configurations due to flow over the weir with orifices
were contrasted with those of the classical sharp crested weir. Quantitative volumes assessments
of local scour and silting utilizing the 11 scenarios were likewise introduced. Large contrasts
between tested cases were reported. |
