|
Keywords
|
Energy dissipation, Height of sill, Slope, Stepped spillway, Skimming flow
|
|
Abstract
|
Stepped spillways are designed to pass high flow discharges over the dams. Energy increases due to high speed of flow on stepped spillway. This energy must be dissipated by suitable way process. Many studies have been done on stepped spillways and effects of factors such as the height of the step, number of steps, slope of step and sill on steps for energy dissipation has been investigated. In this research, the effect of rectangular sills with length of quarter and half of the step bottom length on energy dissipation in skimming flow is investigated. Stepped spillway model contains 61steps with a slope of 33% and scale of 1:15. The results showed that the relative energy dissipation is related to the factors such as the discharge, height and length of sill. The best sill that introduce highest of energy dissipation in stepped spillway had a height of 0.4 times of the step height and with one quarter of the step bottom length. Also the results indicates that by installing the sill on the each steps, the energy dissipation rate increases about 4 to 11 percent with respect to non-sill in step.
|