Hydrodynamic Performance and Cavitation Analysis in Bottom Outlets of Dam Using CFD Modelling

Bottom outlets are significant structures of dams, which responsible for controlling the flow rate, operation, or removal reservoir sedimentation. The service gate controls outlet and whenever this is out order, emergency located at upstream utilized. cavitation phenomenon one common bottom outlets’ problems due to rapid transfer. present research a numerical study pattern in dam’s different openings by use Flow-3D software RNG k-ε turbulence model. investigation carried on Sardab Dam, an earth dam Isfahan (Iran). maximum velocity 100% opening Howell Bunger valve about 18 m/s section below gate, 40% equal 23.1 m/s. For 50% valve’s areas, desired pressure values reduced. Moreover, areas between two gates, possibility area can be reduced installing aerators. Dam’s has relatively stable proper conditions, there no troublesome hydraulic phenomena such as local vortices, undesirable variations pressure, tunnel, separation critical entering into branch.