The Applicability Research And Simulation Analysis Of The Turbulence Model Of The Internal Flow Field Of The Turbine

The hydraulic turbine is the core component of the hydroelectric power generation.The flow pattern of the internal flow field directly affects the safety and stability of the operation of the hydropower station.In this paper,the F-99 Francis turbine is selected as the research object,and the three-dimensional flow model of each part of the volute,water guide mechanism,runner and draft tube is established.Mesh generation is carried out and numerical simulation is carried out by computer.According to the comprehensive operation characteristic curve of the runner,three typical working conditions,namely small flow,optimal and large flow conditions,are selected to carry out the research of the flow field of the turbine internal flow field.For the applicability of turbulence models in the calculation of the internal flow field of turbine,using RNG k-?,Realizable k-? and k-? SST three turbulence models,to solve the flow situation of the internal flow field of turbine,and compared with the experimental results to analysis the accuracy of turbulence model.It will provide a reference for choosing a more suitable turbulence model for unsteady state calculation in the future.It will improve the accuracy of calculation and facilitate more accurate understanding of the flow and flow field inside the turbine.Under three typical working conditions,the unsteady turbulent model is used to calculate the unsteady flow of the internal flow field of the turbine.The flow patterns of the internal flow field of the over current components are analyzed,including the distribution of the volute and the rotation,the velocity field and the vortex structure in the tailpipe.Then the results of the torque value of the rotary wheel,the pressure and the pressure fluctuation at the monitoring point are calculated,and the results are compared with the experimental results.It can preliminarily understand the error analysis and deduce the cause of the pressure pulsation,and provide a reference for the accuracy and accuracy of the internal flow field of the turbine and the stable operation of the unit.