PERFORMANCE EVALUATION OF STEPPED SPILLWAY UNDER NAPPEE FLOW CONDITION

Abstract: A stepped spillway is a spillway with steps on the spillway chute to assist in the dissipation of the kinetic energy of the descending water. This reduces size or eliminates the need for an additional energy dissipator on downstream side. The energy dissipation depends upon the step height and discharge. In this study effect of number of steps and discharge on energy dissipation were studied using computational fluid dynamics (CFD) approach. Effect of number of steps and discharge was evaluated for nappe flow conditions.This study shows that as number of steps are increased the energy dissipation decreases and also increase in discharge results in the decrease in energy dissipation under nappe flow.

Keywords: Mean Kinetic Energy, Energy Dissipation, CFD, Number of steps and Discharge.