Evaluation of Flow behavior over Broad-Crested Weirs of a Triangular Cross-Section using CFD Techniques

Yıl 2018, Sayı: 2, 361 - 367, 19.08.2018

Mohammad A. Al-dabbagh Sulaiman D. Al-zubaıdy

Öz

Weirs are
barriers placed across a river and designed to control the flowing water in
order to prevent floods, make waterways operable for inland navigation and
measure flow discharge. Although there are many types of weirs, mainly used
ones are sharp-crested, circular-crested (cylindrical), broad crested and ogee
weirs. In the present study, triangular broad-crested weirs are numerically
investigated under different flow conditions. Different interior angles of 90^o,
100^o, 110^o and 120^o are included for the
opening of weirs. The flowing water over weirs is simulated using CFD
techniques and evaluated at different flow regimes with inlet discharges of
0.012 m³ s^-1, 0.036 m³ s^-1and 0.06
m³ s^-1. The simulation results have shown that the water
level upstream the weir is inversely proportional to the opening angle, where
an increment of 10^o in the opening angle leads to a drop in water
level about 1.5 cm. In addition, applying a discharge of 0.012 m³ s^-1,
an uncovered region with water is created downstream the triangular broad-crested
weirs, while the bed downstream of the rectangular broad-crested weir is
covered with a thin layer of water at the same flow discharge. The
aforementioned results are compared with a comparative data and show good
agreement. By using triangular broad-crested weirs, it is important to measure
the wake region and the hitting point of falling water downstream the weirs
where this area must be strengthened well in order to resist water power and
reduce the risk of drift.

Anahtar Kelimeler

Weir, CFD, V-notch, Broad-Crested weir, Turbulence model

Kaynakça

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