Experimentally Verified Numerical Investigation of the Sill Hydraulics for Abruptly Expanding Stilling Basin

Energy dissipation structures, particularly stilling basins, are critical for defining the hydraulic jump characteristics that are suitable. Appropriate sill geometry for abruptly expanding stilling basins has been investigated and a central rectangular sill has been proposed in the literature. This study has examined the suggested central sill and alternative flip buckets for abruptly expanding stilling basins. A series of experimental and numerical studies were carried out for two different heights of the central sill and two different flip buckets. Simulations have been evaluated using experimental data of laboratory scale, which indicated that they were acceptably precise. For the simulations, the k-epsilon turbulence model RNG module was preferred using the volume of fluid methods. The PISO approach was chosen to resolve this equation system numerically. The results showed that the hydraulic jump characteristics are strongly influenced by sill geometry. For the Type-3 sill negative static pressures have not occurred and performs better at energy dissipation than other geometries examined in the study. Higher pressures occurred on the rectangular prism-shaped sills. Maximum static pressure happened on the Type-2 sill. The least static pressure was seen in the Type-4 sill type.