Hydraulics of Flow Through and Over Fayoum Weir with Rectangular Bottom Openings

Fadhil M Al-Mohammed

doi:10.3759/jowrem.v3i2.1833

Abstract

Fayoum standard weirs have been modified by adding number of bottom openings to convey much water to downstream direction. This study aims to investigate the effects of using different configurations of Fayoum weirs with rectangular bottom openings on flow characteristics under different dimensions and number of openings. 46 weir configurations with height of 25 cm were used in this study, divided into four groups A, B, C and D. Each of groups A, B and C has 15 configurations, while group D has one configuration. Configurations of each group differ in the number, arrangement, width and height of bottom openings. Tests were conducted using openings widths 1, 2, and 3 cm while openings heights of 1, 3, and 6 cm. In this study, the applied discharges were varied between 11.97 and 30.35 l/s. Two hundred and thirty one test runs were carried out to investigate the effects of using bottom opening on hydraulic characteristics of flow passing through and over Fayoum weir with bottom openings. A comparison between the weir with and without bottom openings was carried out as to discharge conveyance and discharge coefficients. The general equation for rectangular weir and the dimensional analysis (Buckingham Pi-Theorem) method were used to estimate the discharge passing through and over the weir. The results showed that for same head of water over the crest of weir, the applied unit discharge increases by increasing the width, height and number of bottom openings. The results also showed that there is a clear convergence between the discharge coefficient values for both analysis methods.