In this study highlights the possibility of increasing the discharge of side channel using inclined side weir with different crest height upstream of flow, five models were used and flow profile were studied along the side weir. Devised an equation to calculate the coefficient of discharge for the rectangular sharp crested weir, and used for calculated the discharge passing over the side weir for all cases of inclined side weir and compare it with the laboratorymeasured data. The laboratory data proved the correct of theoretical equation and observed to increase the discharge of the inclined weir by (40%) compared to standard horizontal weir.

The present study focuses on the concept of an elementary discharge coecient that is related to the discharge owing through an elementary strip along the side weir length. Simulations of discharge and water depth elevation were done. It is shown that the predicted discharge was in agreement with the one observed, within an error not exceeding 10compared with other works, and was increased when the side weir was installed as oblique against the ow direction

In this paper, the inclined side weir discharge coefficient was studied using a side weir with three different crest angles (θ = 4°, 8°, 12°) fixed either against and in the flow direction, and the results are compared with those from a horizontal side weir crest (θ = 0°). In total there were seven models. The results show that the De Marchi assumption of constant energy for all side weir crested angles is acceptable, and thus that the calculated weir discharge value can therefore be undertaken. An equation for the discharge coefficient was obtained for an inclined side weir, so the value of Cd for crest angle θ = 12° increased by 13.6% with respect to the value for θ = 8°, by 29% with respect to that for θ = 4°, and by 39% with respect to that for the horizontal case (θ = 0°), for a crest inclined against the flow direction, while when the crest was inclined in the flow direction all those values exceed, to 14.5%, 31.0%, and 40.7%, respectively. This means that the discharge increases with increasing side weir crest angle, so when we want uniformity in the flow direction and exceed discharge we need to make the side weir crest incline against the flow direction while when we want furthermore discharge we need to make the side weir crest incline in the flow direction.