Flood Discharge And Flushing Process Numerically Simulated By CFD

Spillway energy dissipation and river bed erosion are crucial for the safety and normal operation of the whole hydro-junction.The internal flow field is complicated and has significant three-dimensional characteristics.However,physical model test,one-dimensional and two-dimensional methods can not meet the needs of reach.As a result,it is necessary to apply the method of three-dimensional numerical simulation to simulate the flood discharge and scouring process.There have been many achievements in the study of the three-dimensional numerical simulation of the flood discharge process of the discharge structures,but there are still many problems that have not been solved well.For example,the lack of numerical simulation method for the accurate simulation of sedimentation process;lack of numerical simulation method to optimize the design of energy dissipator;lack of reach on the gate opening options and so on.Based on the previous research results and experience,this paper uses the method of three-dimensional numerical simulation to simulate the flood discharge process of the spillway in order to solve the problems listed above.In this paper,the commercial CFD software FLOW-3D is used to simulate the three-dimensional process of the flood discharge process.Three main tasks are carried out in his thesis:the study of the sedimentation process is carried out;the optimization of the size of the energy dissipator and the optimization of the gate opening options.Specific job categories are as follows:1.Simulate the flushing process of a sedimentation basin accurately,and optimize its running condition.The flushing process of a sedimentation basin which involves the water and sand is a complex process.Applying the numerical simulation method to simulate,analyze and study the process is important for the structure design,arrangement optimization and the selection of working condition of a sedimentation basin.In this paper,the classical model test is simulated and the results are in good agreement,and the sand erosion process of a specific project is simulated.By comparing the flushing efficiency of different working conditions,the sedimentation basin operation plan was optimized design.2.Apply numerical simulation method to optimize the design of flaring gate piers.When the contraction ratio of the flaring gate piers shrink than a certain time,the water flow in the dam surface will change with the tail angle changes,resulting in different energy dissipation effect.In this paper,the numerical simulation method is used to simulate the flow patterns for optimizing the flaring gate pier angles for a specific project.The internal flow mechanism and the optimal flaring gate pier angles obtained.3.Optimize the gate opening optionsThe different gate opening options will directly affect the discharge of water flow,thereby affecting the floor pressure and downstream river bed erosion features,so a reasonable gate opening options of hydraulic building safety is very important.Based on the previous chapter,the optimization of the gate opening options is carried out on the basis of the good agreement of numerical simulation and the experimental results.The influence of the gate opening options on the downstream scouring is analyzed,and the optimal gate scheduling scheme is obtained.