Study On Dissipation Characteristic Of Transitional Steps Of Stepped Spillway

As the important discharge structure in hydro-junction,in order to prevent and avoid the water flow from the dam surface erosion of the riverbed and the slop,majority of hydraulic engineering are adopted spillway to dissipate energy or are built stilling basin.Stepped spillway have been drawn widely interest by because of high energy dissipation.Especially the study of energy dissipation characteristics of transitional steps of stepped spillway that have great scientific significance and engineering application value.Based on the stepped spillway,this paper adopts theoretical analysis,model test research and numerical simulation to research the effects of transitional steps on dissipation characteristics of stepped spillway,the main research result is as follows.(1)Conclude the basic theory on the dissipation characteristics of stepped spillway,make clear the reason and improving engineering of unfavorable flow,in order to provide theory support for optimization scheme of stepped spillway.(2)The model test was designed based on the structural arrangement of stepped spillway and analyzed the hydraulic characteristics.The result of the test showed aeration starting point was relatively backward,and the pressure of some steps was negative which was unfavorable to spillway surface.Aiming at the(3)Based on the structural arrangement of stepped spillway,numerical simulation was adopted to analyze the dissipation characteristics.It was found that the aeration starting point was relatively backward which was consistent with the conclusion of the model test.Aiming at the unfavorable factor that aeration starting point was relatively backward,optimization scheme of setting the transition step was proposed,and numerical simulation was adopted to analyze the schemes of different transition steps.The optimal optimization scheme was developed after the analysis were compared.