Document Type : Research Paper
Hydraulic condition of stilling basin, in particular, the flow rate passing through chute spillway, as well as the location of hydraulic jump plays an important role on velocity fluctuations in a stilling basin. In this study, effects of the hydraulic jump location and flow discharge in stilling basin on the velocity fluctuations are evaluated. The experiments were performed in a 1:30 scale model of Glabar Dam spillway for discharges of 221.7, 355.8, 450 and 592.5 (m3/s). The discharges ranges are for 1,000 to 10,000 years return period. The flow velocities in different locations inside of stilling basin have been measured near the wall and centre of basin. The experiment results show that flow velocity fluctuations are considerably affected by the discharge and the location of the hydraulic jump. The most energy lost was in discharge 355.8 (m3/s) where jump was on the shut blocks. The lost was nearly 93% after the jump compared to the energy before the jump.