Ogee Crest Weir Head-discharge Relationships | Chapter 9 | Research Highlights in Science and Technology Vol. 7

 The objective concerning this study is to question dependency of discharge coefficient (C) in arched weirs with hydraulic limits in both free and submerged flow environments. Discharge over an ogee cascade is related to the distance of the weir, upstream total head above the wall crest, and the discharge cooperative. The discharge coefficient is affected by several factors. In this study, few parameters that influence discharge coefficients of arched weirs are investigated. These factors involve: the weir hard to do slope, apron promotion, and downstream submergence. In this regard, rounded line or object weir tangible models were fabricated. These models hold: an ogee weir accompanying a vertical hard to do face, ogee weirs with apt upstream faces (18, 33, and 45 points), ogee weirs accompanying downstream apron thicknesses of 3, 5, 7, and 10 cm in free flow and an rounded line or object weir accompanying a vertical hard to do slope under submerged flow conditions. Results show that for all arched weirs, the discharge coefficient (C) increases accompanying increasing P/He, and then debris constant (P is the chute height and He is the head above the movable barrier at entrance crest). The value of the discharge cooperative decreases from 2.25 in free flow conditions to 2.15 accompanying submerged flow environments. For a constant head over the ogee weirs (He), the discharge cooperative decreases with growing downstream apron advancement and submergence. The relative discharge cooperative shows a constant current initially, with growing hd/He, then later shows a cutting down tendency (hd is the dissimilarity between the downstream head and the arched spillway ridge). The threshold value for plunge ratio (hd/He), is 0.75 in the arched weir in this place study. With increasing submergence percentage from 0.75 to 1, the relative discharge coefficient (Cs/C0) decreases from 0.88 to 0.24.

Author(s) Details:

Farzin Salmasi,

Department of Water Engineering, Faculty of Agriculture, University of Tabriz, Tabriz, Iran.

John Abraham,

University of St. Thomas, Minnesota, School of Engineering 2115 Summit Avenue St. Paul, Minnesota 55105, USA.

Please see the link here: https://stm.bookpi.org/RHST-V7/article/view/11404