Numerical Simulation Of Fluid-solid Coupling Of Turbine Runner Of Yuzixi Hydropower Station

During the operation of the hydro-turbine unit of Yuzixi hydropower station,there are some defects such as large vibration of the turbine,cracks and falling of the turbine runner blades,and the turbine can not operate at full load,the service life of the turbine will be greatly shortened,which will endanger the safe operation of the unit and cause economic losses to the power station.The internal flow characteristics,fluid-structure coupling characteristics and cavitation characteristics of the mixed flow turbine of Yuzixi Hydropower Station under some typical load conditions are studied in this paper,which provides important references for solving the defects of the turbine of Yuzixi Hydropower Station and optimizing the design of other turbines.His main research work and achievements are as follows:1.Three-dimensional geometric modeling was carried out for the whole flow passage components(including volute,fixed guide vane,movable guide vane,runner and draft pipe)of the turbine of Yuzixi Hydropower Station,and the geometric model of the turbine was divided into computational grids.2.With a standard turbulence model to simulate the turbine working condition of the stationary flow calculation,analysis of 9 kinds of flow characteristics and operating conditions of turbine cavitation was calculated and the vortex band,the results show that turbine in low head small load and big load condition of high water pressure flow condition is bad,cavitation mainly appear in the runner blade out of the water,under 100% load vacuoles appeared in the runner blade into the water,not only in the center of the runner exit,tail pipe free imports are taking place and will cause strong vibration and cavitation damage of the unit.3.With the aid of ANSYS Workbench software,on the stationary flow calculation results,the turbine runner uniflow solid coupling calculation of deformation analysis was carried out on the wheel,respectively,statics analysis and modal analysis,the results show that turbine runner blade junction and blade outlet and inlet and the champions league ring junction deformation,the stress concentration phenomenon is obvious,easy to cause crack of blade and fracture.Through the unsteady flow calculation of the turbine,the maximum deformation,stress and strain in the runner are analyzed,and the position where the runner blade is prone to crack is obtained.4.The research results are of practical value for exploring the unstable characteristics of hydroturbine units in the actual operation of hydropower stations and are of great significance for finding out the internal flow dynamic factors leading to the defects of hydroturbine runner.