Method for Regulating Water Flow Structure of Two-stage Stilling Basin with Large Diffusion Angle
When the diffusion angle on each side of the two-stage stilling basin is 12°,it is prone to generate a large-scale reflux zone near each wing wall at medium and low water levels,which will cause the mainstream to be centered.Based on the physical model test,an engineering method and its suitable layout location were studied to enhance the later-al diffusion and homogenization effect of water flow in the stilling basin.The results indicate that setting a diversion bot-tom sill in the first stage stilling basin can easily generate rapid splashing at low water levels.The range of water flow drop zone in the apron increases compared with the original scheme,and the maximum drop length can be 1.77 times that of the original scheme,which is not conducive to the safety of downstream erosion prevention.Setting a diversion bottom sill in the middle of the second stage stilling basin can significantly increase the longitudinal outflow velocity at the left and right banks.The lateral distribution of outflow velocity is more uniform,and its dispersion coefficient can be reduced by an average of 23.1%in the middle and low water level range compared with the original scheme.At low water levels,the maximum drop length of the water flow out of the second stage stilling basin can be reduced by 22.6%.It can also raise the water depth in the first stage stilling basin,improve the energy dissipation rate of both stage stilling basin,increase the total energy dissipation rate to a maximum of 55.53%,and further enhance the overall energy consumption and ero-sion prevention performance of the stilling basin.The results can be used as a reference for the design and reinforcement plan of the gate.
large diffusion angletwo-stage stilling basindiversion bottom sillhorizontal homogenizationsuitable layout location
万方数据
维普
