Comparative study of the discharge coefficient of streamlined weirs

Document Type : Original Article


1 Shahid Chamran University

2 Lorestan University

3 yazd university



Nowadays, streamlined weirs including circular crested weirs and hydrofoil weirs have been introduced as the weirs with high discharge coefficient (Cd). In this study, the Cd e of circular crested weirs including cylindrical, semicircular and quarter-circular weirs were compared with the hydrofoil weirs. This was done using data published in reputable journals. The trend of the published data showed that the o Cd f of the semicircular and cylindrical crested weirs are close to each other and vary between 1.00 and 1.40. The Cd e of the quarter-crested weirs varies between 1.00 and 1.25 and the Cd of the hydrofoil weirs varies between 0.95 and 1.05. It should be noted that for all models, the range of the ratio of crest height to weir height varied between 0.5 and 2.10. The results showed that the Cd of the semicircular weir was about 30% higher than that of the hydrofoil weir. The Cd of semicircular weirs is about 10 percent higher than that of quarter-circular crested weirs.