Study On The Applicability Of Numerical Simulation Method For Hydraulic Characteristics Of Side Inlet/outlet Of Pumped Storage Power Stations

With the increasing capacity of China's power grid,pumped storage power stations play an increasingly important role in power regulation by virtue of the advantages of high energy recovery efficiency,rapid response and long service life.As an important part of the power station water transmission system,the side inlet/outlet directly affects the safety and benefit of the power station.In recent years,with the continuous development of theoretical and computational performance,numerical simulation has become an important method to study the hydraulic characteristics of side inlet/outlet.The internal water flow in the side inlet/outlet is a turbulent movement,and the water flow conditions are relatively complex.Therefore,the selection of numerical simulation method has an impact on the numerical simulation results of the hydraulic characteristics of the side inlet/outlet.In this paper,a variety of turbulence models,grid scale and wall function are used to conduct numerical simulation of single side inlet/outlet of the lower reservoir of qingyuan pumped storage power station.(1)Acoustic doppler current meter(ADV)and laser particle image velocimeter(PIV)were used to test the monomer model of side inlet/outlet of qingyuan lower reservoir.Under the conditions of inlet and outlet,the head loss coefficient of inlet/outlet is reasonable,the velocity distribution of sewage gate section is uniform,and the low velocity zone is found in the inlet/outlet.(2)Four turbulence models,standard,RSM,LES and DES,were used to simulate the single side inlet/outlet of qingyuan lower reservoir.Considering the accuracy of calculation and calculation time,the error of calculation results of the four turbulence models is small in the inlet flow condition,and the calculation efficiency is high by using the RSM model.In the flow condition,RSM model has small error and relatively short time,and high computational efficiency.LES model has the highest computational accuracy,which has certain promotion significance.(3)Based on the calculation of RSM model,three mesh scale models of 0.024 H,0.018 H and 0.013 H were numerically simulated.In the case of inlet and outlet flow,the numerical solutions of the three grid scales are close to the analytical solutions for hydraulic characteristic parameters such as head loss coefficient,average velocity of fouling gate section and non-uniform coefficient of velocity,etc.The three grid scales have little influence on the numerical simulation results.When the grid scale is0.205 m,the computational requirements are basically met.(4)On the basis of RSM model and 0.024 H grid scale,three different wall functions,namely standard wall function,extendable wall function and non-equilibrium wall function,were used to simulate the single side inlet/outlet of qingyuan lower reservoir.Considering the calculation accuracy and calculation time comprehensively,the calculation accuracy of non-equilibrium wall function is higher than that of the other two wall functions in the inlet and outlet flow conditions.Meanwhile,the calculation time on the workstation is only 2 ? 3 hours,and the calculation efficiency of non-equilibrium wall function is higher.(5)In this paper,the numerical simulation effect and computational efficiency of the single side inlet/outlet of qingyuan under the conditions of various turbulence models,mesh scale and wall function are compared and analyzed.When the RSM model,0.024 H mesh scale and non-equilibrium wall function are adopted for the inlet and outlet flow conditions,the computational accuracy and efficiency of the numerical simulation are relatively high.