Investigation Effective Factors On Energy Depreciation Of Stepped Spillways

Subject Areas : hydraulic structures

saeed  razmara ¹ (Civil Engineering Structures, Islamic Azad University, Tehran South Branch)
Abbas  mansori ² (Assistant Professor of Islamic Azad University, Islamic Azad University, Tehran, Iran.)

Received: 2019-01-02 Accepted : 2019-06-01 Published : 2018-11-22

Keywords: Flow regime, Stacked overflow, Stage shots, Factor correction coefficient, Floating numerical method,

Abstract :

In recent decades, stepped spillways have been a significant role in this case.. This research is based on The flow energy calculated on these edged steps and simple steps in nappe flow and skimming flow regimes. Difference in height, width and edge slopes will determine the effects of each of these parameters on energy dissipation ratio And then the analysis of sixteen model with different geometries were conducted by Gambit and Fluent software for two discharges ٣/٦ lit/s (nappe flow) and ٢٥ litr/s (skimming flow) by the total of ٣٢ models. And with regard to the results achieved, the influence of the edge for nappe flow has been regarded according to Chamani and Rajaratnani equations. With regard to the results, it is suggested that the existence of the edge at the step end can be enhanced the energy dissipation ratio along the stepped chute. Of course the ratio of this effect in flow and skimming regimes are not the same and these effects are decreased by increasing of discharge.