Study On Influence Of Drop Sill After Gate On Flow Characteristics

The water flow problem on the broad crest weir has been widely used in practical engineering.Studying out the criteria、Characteristics of submerged outflow and a reasonable calculation method of submergence coefficient has a great value for engineering application and academic theories.But at present,there is no perfect way to determine submergence correction factor which is produced by falling sill.This paper list the present method which is used to solve the problem of the submerged discharge sluice hole on the broad crested weir first.Deeming present calculation method of the submerged discharge on the horizontal floor is applied to the broad crest weir directly is inaccurate.Propose to lead into submergence correction factor β= h’/hc",when ht>h’=βhc" is submerged flow.Then calculate by using the numerical simulation,using the k-ε turbulence model,using VOF to track liquid free surface,using the computational model of gas-liquid two-phase flow,establishing two-dimensional broad crested weir model.d/e、l/e are variables.According to sill size commonly used in Engineering,select d/e=0.2、0.4、0.6、0.8、1、2 respectively,and select l/e=1、2、3、4、5、6、7、8、9、10 respectively,to set up a numerical model of 60 conditions.Calculate the submerged flow in wide crested weir.Obtain the change regulation which is about variation of flow and velocity with height and length of falling sill is consistent with the theoretical analysis,then according to the calculation results to summarize submergence correction factor.Finally,the numerical simulation results are compared with the classical experimental data and the experimental data of our laboratory.Data consistency is high.Show that the numerical simulation method is reasonable.The research results of this paper can be directly applied to the calculation of submerged flow of wide crested weir.Provide the basis for the project application.Makes an important contribution to improve discriminant method of the submerged discharge sluice hole on wide crested weir...