Three-dimensional Flow Pattern Analysis And Research On New Bottom Axis-driven Flap Gate Of Ancient

As a water-retaining structure, compared to traditional gates,bottom axis-driven flap gate has advantages such as easy to operate, simple structure, beautiful appearance, less investment in construction, easy to install and maintain.Although bottom axis-driven flap gate has a history for nearly a century,influenced by the steel and related technical constraints,it developed slowly, in recent years,it has gradually been widely used. Based on this, the flow pattern of the projects, flow rate analysis has important engineering significance.In this paper, test methods and three-dimensional finite element method are used to analyze water conditions, the flow rate of Ancient Yellow River hub.Test model size is selected based on the the gravity similar principle of the hydraulic model design, and model material is selected according to the principle of resistance similarity, flow rate is determinated through the the LDY intelligent electromagnetic flowmeter.The flow rate of new bottom axis-driven flap gate is measured at different water depths,different locations once in20years,50years,100years conditions, and use the of chemical reagents and chemical particle tracking to get the bottom and the surface of the water flow profile.The test data analysis results showed that:in the actual project,the flow rate at the midline first increases and then decreases in the direction of flow;at the same cross-sectional of the model, velocity distribution shows a trend of both ends of the middle; flow rate at different depths of the same cross-sectional of pier contraction section reaches a maximum between one-third to two-fifths of the depth from the surface.At the same time, sediment deposition test is carried on the gate, the results show that there is a linear relationship between gate maximum opening angle and sediment deposition thickness.To verify the adaptability of the new bottom axis-driven flap gate of Ancient Yellow River hub and to propose structure optimization design measures of new bottom axis-driven flap gate,make it possible to study on follow-up sediment-laden flow.Using the CFX turbulence default model to conduct three-dimensional numerical simulation on the project, using non-slip grid technology to conduct simulation on the gate was under the same conditions as the test,a the flow line, the flow rate of cloud images and velocity vectors of the model are obtained, explain the reason of the condition by analyzing the results.Compare the measured data of model with the calculation results by three-dimensional numerical, the main conclusions are basically the same, the difference is mainly produced in the downstream segment. Through research, on the one hand, the test verifys the rationality of the model test and the effectiveness of numerical simulation,on the other hand, the main reason for the difference appeared is analyzed. The findings and conclusions of this paper provide the basis for the project in the sediment-laden river, and provide reference for other similar projects.