experimental and numerical investigation of bottom outlet hydraulic model

Using experimental models along with conducting numerical analysis have been widely used in performance recognition and optimization of hydraulic equipment. numerical modeling has lower cost rather than experimental one; however practical tests are commonly used because of the hydraulic structure importance especially in dams. meanwhile, numerical methods could be used for the future designs by validating numerical models. in this paper, the volume of the fluid method is employed to simulate the free surface flow at the dam bottom outlet form a bell mouth section up to the downstream channel. since the flow through the gates is turbulent, the standard k-ε, reynolds stress model, rsm, and turbulence models are used, and the results are compared. the discharge coefficient and the ventilated air velocity through the vents are computed numerically and compared with the experimental data. comparison between the experimental data and numerical simulation results shows good compatibility, especially in the reynolds stress and turbulence models rather than the k-ε turbulence model. the results show that the maximum error percentage in the simulation of the discharge coefficient and the ventilated air velocity is 9% and 3%, respectively.