Model Test And Numerical Simulation Of Hydraulic Characteristics Of Multiple Gated Spillway

Spillway is one of the main water discharge structures in the water conservancy project.With its role to relieve the excess flow of the reservoir and ensure the safety of the dam.Therefore,it is of importance to study the hydraulic characteristics of the spillway and the downstream scour damage.In this paper,the physical model test on a spillway of a hydropower station is carried out to simulate the main hydraulic characteristics of the spillway.The hydraulic parameters such as surface line,velocity distribution,and pressure of the spillway are simulated,being consistent with the experimental data.In order to study the characteristics of the flow cavity and the completion and diffusion of water flow after the piercing a multiple gated overflow flow on a steep slope of a chute,this paper makes a detailed analysis,obtaining some empirical formulas.Aiming at the downstream scour damage study,the numerical simulation method is used to compare the water tongue characteristics of the two different body types under the nose flap.It is concluded that the differential nasal canal is superior and that the downstream scour is lighter.The main research results of the paper are as follows:(1)According to the test results,the discharge capacity of the spillway meets the requirements,indicating that the elevation of the dome of the spillway and the size of the orifice are appropriate,and that the design of the surface curve and the steep slope are reasonable.The physical model test method is used to optimize the shape of the tail pier body and the aerobic mitigation facility,improving the flow regime of the chute and avoiding cavitation damage.(2)With the distribution patterns of water flow,water surface line,flow velocity,pressure,etc.under the physical model test and numerical simulation under the design conditions and verification conditions of the spillway,and the simulation of the spillway surface line,velocity distribution,and pressure simulated,the comparison between other hydraulic parameters and experimental data is consistent.(3)Using the numerical simulation analysis to compare the characteristics of water tongues of continuous spillway nose choke and differential choke noses in design conditions,including water tongue pitch,water tongue flow state,and water tongue pressure point pressure distribution,the characteristics of the hydraulic characteristics,such as the distribution of water tongue flow velocity,turbulent kinetic energy,and dissipation rate,are obtained to verify the superiority of the differential approach.(4)The numerical simulation method is adopted to study the flow effects of the piers on the steep slopes.The water depth,pressure,and surface velocity in the discharge tanks of the piers are equalized as the standard.The length and flow chart of the convergence of the flow in the porous spillway are obtained with lateral lateral diffusion width empirical relationship confirmed.Taking the water depth behind the pier as the research object,the hydraulic characteristics of the back cavity of the pier are analyzed.(5)Through the physical model test under different working conditions after optimizing the overall spillway body type,a comparative analysis of flow patterns,surface lines,pressures,etc.shows that the optimized spillway has achieved satisfactory results.