Experimental Study On Energy Dissipation Of Flood Diversion Sluice Of Chengzi River And Numerical Simulation Of Hydraulic Characteristics

In the actual operation of sluices,often due to large flow and inadequate energy dissipation,the downstream side slope and apron will have different degrees of erosion,or even building damage,which directly affects the safety of the sluice and operation.Therefore,it is very important to analyze how to effectively eliminate the flow energy after the sluice gate,which can improve the effect of energy dissipation by rationally selecting the structure of the stilling basin and increasing the auxiliary energy dissipation.Taking Chengzi river flood diversion sluice as the research object,with the aid of hydraulic model test,the effect and flow state of the stilling basin and apron section are observed and analyzed,and the relevant numerical calculation is carried out with the fluid calculation software FLUENT.The whole numerical model of sluice was established by Gambit software,and the Realizable k-?turbulent model and VOF method were used to simulate the flood sluice.The main research contents and research results are as follows:(1)According to the similarity criterion of the hydraulic model test,through the normal physical model test,the flow pattern under the sluice and the influence on the downstream energy dissipation facilities and river bed erosion are observed.And the reasonable and feasible design scheme of energy dissipation can provide the necessary basis for the construction and management of sluices.(2)Through the model test of the energy dissipation structure of sluice single curve overflow weir,the results show that the negative pressure of the stilling basin floor is large,the secondary stilling basin and the jet stream area of the apron slope are longer,and the downstream water flow has a roundabout,and the energy dissipation effect is not ideal.The energy dissipation measures of the energy dissipation structure of the single curve overflow weir of the test model are optimized reasonably,and the hydraulic characteristics model test of the optimization scheme is carried out.The results show that the optimized layout scheme of the model can reasonably set the three eliminate bucket in the slope section of secondary stilling basin,and the apron slope reasonable arrangement of the two eliminate bucket,the flow pattern of the apron section is stable,and the flow can be connected well with the river bed downstream of the apron.(3)On the basis of the optimization scheme of energy dissipation structure of single curve overflow weir,the structure of secondary stilling basin of sluice model is designed,and a scheme of two-stage energy dissipation structure of hyperbolic overflow weir is proposed,and the hydraulic characteristics of this scheme model is studied,and the results of two schemes are compared and analyzed.The results show that the energy dissipation effect of the two-stage energy dissipation structure scheme of hyperbolic overflow weir is more ideal.(4)The Realizable k-? turbulent model is used to simulate the energy dissipation structure scheme of single curve overflow weir,the ultimate optimal layout scheme of single curve overflow weir and the scheme of hyperbolic overflow weir energy dissipation structure.Through the numerical simulation of the water flow of the various schemes,the distribution of flow field and pressure field is analyzed,and the calculated results are in good agreement with the model test.Then the numerical calculation and model test results are compared,and the results show that the numerical results are approximately the same as the experimental results.