Study On Numerical Simulation Of CCHE Two Dimensional Water And Sediment In An Artificial Bend Channel Head

The artificial curved channel head is one of the main buildings that can achieve better sand control effect and water stability.It uses the separable motion characteristics of water and sand in the curve to solve the contradiction between water diversion and sand control.The research on the movement process of water and sediment in bends is of great significance to river harnessing and development projects,river ecological restoration,and sediment removal.In this paper,the numerical simulation method is mainly used to establish a two-phase numerical model of curve flow and sand using CCHE.The two-dimensional numerical simulation of water and sediment flow in an artificial curve head is obtained.The following conclusions are obtained:(1)Get the elevation of the surface of the bend under a certain working condition,the lateral gradient of the free surface of different cross-sections,the lateral transport of sediments at different times,and the deformation of the river bed after siltation and sedimentation,and the simulation results and physics of the elevation of the surface of the curve The model test data are compared and the two are in good agreement with each other to verify the accuracy of the model.By comparing the cross-sectional surface elevations at different locations,the maximum horizontal aspect ratio of the water surface is found at the bend point and disappears at the exit point;Based on the comparative analysis of sand transport,this model can fully simulate the effect of sediment scouring and sedimentation under the effect of the loop flow.(2)A two-dimensional mathematical model is established to simulate the movement of water and sediment in the bend of the canal,and the effects of different flow rates on the water and sediment movement characteristics of the curves are studied.The characteristics of the water and sediment movements in the curves are simulated and analyzed.Numerical simulation results show that the greater the incoming flow Q,the greater the value of the vertical average velocity of the flow section along the flow direction is closer to the centerline position;otherwise,the mainline deviation will be greater;as the flow Q increases,the horizontal contrast ratio decreases It also increases continuously,and the maximum position moves forward.As the flow Q increases with the upstream,the effect of siltation and siltation in the curve channel decreases first and then increases.(3)Using Fluent and CCHE,two different mathematical models respectively to conduct numerical simulations on the motion patterns of water and sediment in bends.The height of the water surface on the side of the concave bank and the convex bank of the curve,the average flow velocity of the whole section,and sediment erosion and deposition are calculated.Time-consuming and other aspects of numerical simulation results and physical test results are compared and analyzed,the study shows that: CCHE model can more effectively and accurately simulate the complexity of the curved water and sediment movement characteristics.