Investigation of different geometric shapes of sills on the discharge coefficient of a vertical sluice gate

Document Type : Research Article


Department of water engineering, Tabriz University, Tabriz, Iran.


Gates in dams and irrigation canals are used for control of discharge or water surface regulation. To determine the discharge under a gate, a discharge coefficient (Cd) should be determined. This study investigates the effect of sill shape under the vertical sluice gate on Cd. Both of sill shape and sill height were investigated. The investigated shapes comprise polyhedral and non-polyhedral sills. The results showed that circular sill was the most effective and triangular sill was also the proper shape of polyhedral in increasing Cd. Circular sill increases Cd at least 23% up to a maximum of 31%. In addition to shape, sill height was also important in the determination of Cd. Using dimensionless parameters and regression analysis, an equation for prediction of Cd in free flow condition with and without sill was presented. The developed equation coincides with the published previous researches.


Main Subjects

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