Enhancement of Energy Dissipation Using Combination of Solid Roller Bucket and Type II Stilling Basin for Ogee Stepped Spillway

Abstract

AbstractOne of the most critical factors in the design of a hydraulic system is the energy dissipation arrangement for high-velocity flow in an ogee spillway. The release of excess water from crest to toe of the ogee spillway generates a large amount of kinetic energy. This would result in scour and erosion on the spillway's downstream face. Many different forms of energy dissipators have been used for ogee spillways in the past. However, they have energy dissipation, scouring, and erosion issues. The aim of this study is to create a physical working model of an ogee stepped spillway with a combination of solid roller bucket and type II stilling basin as an energy dissipator for the Khadakwasla dam in Pune (India). Two sets of phase models for a design discharge of 2700 m3/s were used in laboratory experiments. The non-dimensional parameter (yc/h 0.8), nappe flow, and Froude number must be held within acceptable limits with 12 and 9 steps, respectively. The model results show that the 9-step model (Set 2) achieved 80.24% energy dissipation for a 4 m head with a controlled value of non-dimensional parameter up to 0.69, which is the highest energy dissipation among all sets of subject models. As a result of the current model analysis, it was discovered that the combination of a solid roller bucket and a type II stilling basin is the best energy dissipator for an ogee stepped spillway.KeywordsEnergy dissipationSolid roller bucketType II stilling basinNon-dimensional parameterOgee stepped spillway