Hydraulic model experiment of energy dissipation on the horizontal and USBR II stilling basin

Abstract

Flow conditions on overflow systems can result in construction failure, mainly due to the high flow energy. Stilling basin at downstream of the spillway is useful for reducing flow energy. It can reduce the destructive force of water flow. Controlling the hydraulic jump is an important part that includes the jump’s energy, length, and height. The physical hydraulic model was carried out with several series, by making a series of bottom lowering of horizontal and USBR II stilling basin. The experimental study is expected to represent flow behavior in the overflow system regarding flow conditions and energy dissipation. Based on the analytical calculation of flow velocity, the amount of flow energy that occurs at each control point is calculated. The control points are the starting point of the spillway, the chute way toe, and flow depth after the hydraulic jump. The energy loss can be calculated for each control point, while the efficiency of energy dissipation on stilling basin is calculated at the downstream flow depth after the hydraulic jump. Velocity calculated by dividing discharge per unit width by water depth which is based on the flow depth measurement data in the hydraulic model.

Double sill stilling basin to enhance energy dissipation for a strong hydraulic jump with a high Froude number

“…Froude number is the important parameter that characterizes supercritical flow. A stilling basin is needed at the toe of the chute to reduce the energy of supercritical flow [2], [8]. Hydraulic jumps are very useful as energy dissipators in supercritical flows.…”

“…Several studies have been carried out to determine the velocity field and base shear stress in hydraulic jumps [2], [7]. There have been many previous studies that discussed the effectiveness of energy dissipation [9], [10], [11], but there are still few studies that discussed the effectiveness of double sill stilling basins.…”

Experimental and numerical modeling of various energy dissipater designs in chute channels

“…They dealt with the hydrodynamic design aspect of jump-type energy dissipaters by experimentally and analytically along with comparison of various energy dissipaters. Based on estimating the uplift and hydrodynamic forces on energy dissipaters, although jump-type energy dissipaters with only one end sill are sufficient for higher velocities, it was not recommended to use it for head above 100 m. Dermawan et al (2021) carried out the physical model study by experimentally bottom lowering of horizontal and USBR II stilling basin. It was expected to represent flow behavior in the overflow system regarding flow conditions and energy dissipation.…”