Sebastian W.B. and Walter H.G. (1971). “free overfall as flow measuring device”, jou. Irrig. And Drain. Eng., ASCE, 97(1),73-83.
 Rajaratnam N.,Durfakula M. and Spyridon B. (1976). “roughness effects on rectangular free overfall”, jou. Hydr. Divi. , ASCE, 102(5),599-614.
 Davis A.C. , Brian G.S. and Richard P.J. (1998). “flow measurement in sloping channels with rectangular free overfall”, jou. Hydr. Eng., ASCE, 124(7),760-763.
 Rouse H. (1936). “discharge characteristics of the free overfall.”, jou. Hydr. Eng., ASCE, 6(4),257-26
 Ferro V. (1992). “flow measurement with rectangular free overfall “, jou. Irrig. And Drain. Eng., ASCE, 118(6),650- 657.
Tikrit Journal of Engineering Sciences (2007) 14(1) 28-43
Variation of Water Depth on Normal and Skewed Broad Crested Weirs
|Ahmed Y. Mohammed||Moayed S. Khaleel||Mwafaq Y. Mohammad|
|Water Resource Eng. Dept., Mosul University, Iraq|
This paper present the variation between brink and critical depths for free overfall, of water over two models of broad crested weirs with different edge, straight vertical and skewed with an angle (30)o. The discharge was measured for the two models and compared with calculated one observed from theoretical equation. The results showed that the calculated discharge is greater than the measured one by (3.5&14.5)% for straight vertical and skew models respectively, and the skew model discharge is greater than that for the straight vertical by (13%). Also, the results indicated that the coefficient of discharge for skew model is less than that for the straight vertical one by (8%). Meanwhile for the same discharges the brink depth for straight vertical model is greater than that for skew model by (11%). The study also showed that the distance upstream the weir (x), at which the critical depth intersected with water surface profile, for skew model is greater than the straight vertical model by (63%).
Keywords: weir, freefall, broad crested weir, brink water depth, Froud number.