Investigation on cavitation occurrence potential in Seymareh dam’s bottom outlet

Cavitation phenomenon is one of the common problems of bottom outlets which convey high-speed flows. In the present study, the possibility of cavitation occurrence is numerically investigated. A numerical model is developed for the flow passing through bottom outlet using FLOW 3D software and K-ε (RNG) turbulent model. The model is operated for reservoir normal and maximum water heads also for various service gate openings. For normal head and different service gate openings, the research results show that cavitation indices are lower than the critical amount (0.2) on the conduit bed for 10%, 20%, 30%, 40%, 50%, 70%, and 80% service gate openings. Also, the side walls of conduit encounter with cavitation phenomenon immediately downstream of service gate for all gate openings. It is observed that the conduit top wall is free of cavitation damage hazard where the minimum cavitation index is equal to 0.46. At maximum reservoir head, the cavitation is not occurred inside the emergency gate slot and on its walls.