Three.Dimensional Numerical Study Of Flows And Sediments In Curved Open.Channel Junctions

Natural river twists and turns,The river and the river meet to form a junction estuary,which controlling the development of water transport,Due to the strong mixing of turbulence which result in big Reynolds stress in the junction estuary,resulting in large local energy loss,Sediment is easy to deposit here,forming shoals and river coasts,which affect the evolution of riverbed and the development of water transportation.Therefore,it is of great practical significance to study the confluence flow,especially the bending flow and sediment transport at the junction.FLOW3D and MIKE3 are commonly used software in hydraulic engineering.,They can be used for numerical simulation of hydrodynamic,sediment,pollutant and so on.FLOW3 D takes the complete N.S equation as the governing equation.MIKE3 takes the three.dimensional shallow water equation which assumed by static pressure as the governing equation.In this paper,the classical experiments are used to verify the two models,according to the results of the model verification,a suitable tool is adopted to carry on the follow.up research.Firstly,through the comparison of water level and velocity,the model is verified by Shukry curved sink test.The water level,the size of the separation zone,the transverse velocity and the longitudinal velocity are compared with the measured values in the Shumate straight channel intersection test to verify the intersection flow of the model.Taking Zeng Qinghua 120 o bend sediment scouring and silting test,the sediment scouring and silting module verification is carried out by comparing the experimental data and the simulated values of the bed height variation of typical cross.section bed to verify the sediment scouring and silting module.Then,with the selected model,Establishment of curved intersection Model of concave Bank intersection and Convex Bank intersection,For concave and convex intersections,simulate three working conditions which their flow ration are 0.25?0.417 and 0.75.Through the analysis of the water level,flow field,separation zone size and trace under each working condition,the influence of different flow ratios and the intersection of different banks on the flow characteristics of the estuary is analyzed.Finally,the simulated flow field under different working conditions is used as the initial condition of the sediment scouring and silting module,and the sediment scouring and silting module is added to simulate the scouring and silting of the river bed under the conditions of different flow ratio and the intersection of different banks.