Energy Dissipation in Stepped Spillway Equipped with Inclined Steps Together with End Sill

Abstract

Dissipating the flow energy while passing over spillway has a certain number of importances. The basic rhyme or reason is that dissipating the large flow energy plays a significant role in maintaining the safety of dam downstream and due to this fact the size of stilling basin will tremendously reduce, cost of construction will be more economical or even generally this phenomenon might result in the elimination of stilling basin. To serve this purpose, various ways have been offered and used since a long time ago. Precise selection of dissipater types wields prominent role in enhancing the energy dissipation efficiency. One of proper ways of dissipation is to use stepped spillway as a dissipater. In this study, the experimental procedure and laboratory work has been conducted to scrutinize whether the rate of energy loss on stepped spillway using Inclined Steps together with End Sill increases. In order for this investigation to be more elucidated, inclined steps with different slopes and end sills with different thickness, height and angle of upward is used to determine their influences on relative energy loss. Results show that using Inclined Steps together with End Sill have considerable affects on both nappe and skimming flows, however, energy dissipation in nappe flows is greater than that in skimming flows. Scrutiny and analysis the results of examination comparing to the results obtained from other investigations, clarified that the approach used in the current investigation is more efficient than previous ones.