Double narrow slot buckets energy dissipator in flood discharge of high head,large discharge and narrow valley has certain application values,but the facing water surface of the middle pier is easy to be damaged by the impact of water flow during operation,and the contraction ratio has a greater impact on this situation and the energy dissipation.Therefore,numerical simula-tion was carried out by using the TruVOF method and RNG k-ε turbulence model to study the influence of the contraction ratio β on the jet flow pattern,energy dissipation rate,pressure of the scour pool bottom and the pressure distribution in the bucket con-traction section under different inflow Froude number Fr.The results showed that the numerical simulation results were basically consistent with the physical model test,and the proper water depth of the middle pier can be obtained by adjusting the contraction ratio β to reduce the impact of high-speed water flow on the middle pier.When β =0.3,the peak pressure Pmax of the down-stream riverbed floor was the least,and the peak pressure core area moved 60 m forward compared with the traditional narrow slit bucket.When β<0.3,Pmax began to increase with the decreasing of β,and the energy dissipation rate decreased.Meanwhile,the confluence location of shock waves appeared near the middle of the contraction section of the bucket,and the pressure distribution along the water depth at the middle line of each section in the flow channel was different before and after the maximum pressure appeared,which was similar to the flaring gate pier energy dissipation.Although Fr had little influence on the discharge ratios,when 2.43<Fr<2.82,the discharge ratio of each type scheme increased significantly,resulting in a significant variation in the floor pressure of the double narrow slot buckets.
关键词
单孔双窄缝消能工/数值模拟/弗劳德数/收缩比/水力特性
Key words
double narrow slot buckets energy dissipator/numerical simulation/Froude number/contraction ratio/hydraulic characteristic
维普
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