Abstract
Slide gates are commonly used to adjust flow in open canals. The discharge coefficient (Cd) for a slide gate is a function of the gate's geometric and hydraulic characteristics. For free flow conditions, Cd depends on the upstream water level and the opening of the gate, whereas for submerged flow, it also depends on the downstream water level. The main aim of this study is to conduct a series of laboratory experiments to determine Cd for inclined slide gates. These tests and models were used to evaluate both free and submerged flows. Experiments with inclination angles of 0 degrees, 15 degrees, 30 degrees, and 45 degrees were studied with different gate openings. The collected data are used to develop equations for predicting Cd. The results show that the inclination of the slide gates has a progressive effect on Cd and increases capacity under the gate. The increase in Cd relates to the convergence of the flow through the gate opening. The produced equation via genetic programming with R2 and a relative error of 0.9431 and 0.0014 had optimal efficiency compared with classical multiple regression models. A comparison with other studies for inclination angles of 45 degrees and 60 degrees was also conducted. (c) 2020 American Society of Civil Engineers.