Mahdi Moghimi - Assistant Professor, Mechanical Engineering Department, Iran University of Science and Technology,
Esmaile Molavi - Msc Graduate, Mechanical Engineering Department, Iran University of Science and Technology,
Mehrdad Kalantar - Msc Graduate, Mechanical Engineering Department, Iran University of Science and Technology,

Manufacturing experimental models along with conducting numerical analysis have been widely used in performance recognition and optimization of hydraulic equipments. Numerical modeling has lower cost rather than experimental one; however practical tests are commonly used because of the hydraulic structure importance in dams. Meanwhile numerical methods could be used for future designs through validating numerical models.In this paper, VOF method has been employed to simulate the free surface flow at dam bottom outlet. Since the flow through the gates has high Reynolds number, the standard two equation k-e and RSM turbulence model could be used. With employing the results obtained from the numerical model, the rate of ventilated air through the vent can be calculated. Air flow rate shows good compatibility, especially in RSM model, in comparison with the conventional empirical data.

cavitation , VOF , dam bottom outlet , ventilation