Design And Test Analysis Of Twisted Blades For Off-design Turbine

As an important part of large-scale industry,steam turbine and gas turbine play an important role in the process of production and life.As an important part of steam turbine and gas turbine,the performance of blade has a great influence on the performance of the whole unit.The core of turbine design is the turbine stage,that is,the aerodynamic design of blades,and a high level of aerodynamic design represents a high level of turbine performance.Turbine flow loss accounts for about75% of the total loss,and the focus of efficiency improvement has always been on the flow part.To improve the efficiency of turbine stage is to improve the efficiency of flow.The blade profile has always played an important role in improving the efficiency of the turbine.In this paper,the blade profile of a twisted blade is designed under the condition that the import and export parameters are known.Through one-dimensional calculation,the physical and geometric parameters of import and export are obtained,and the blade profile is designed by Auto Blade software.Using ICEM-CFD to divide the grid,the flow conditions before and after the cascade are given,the flow field of the cascade is simulated,and the physical parameters of the inlet and outlet of the cascade are obtained.compared with the physical parameters of one-dimensional calculation,the optimal theoretical design scheme is iterated by constantly modifying the geometric parameters of the blade profile.In order to verify the theoretical design of the blade,the blade needs to be tested.Since prototype blades cannot be used for testing at the test bench,Choose Mach number similarity,Reduce the size of the blade by 0.45 reduction ratio for testing.Through three-dimensional solid programming,the test blade was prepared on the five-axis machine tool,and the rest parts such as stator blade were installed on the test bench.The five-hole probe needs to be calibrated before the test,and the cascade test can be carried out after the five-hole probe is calibrated by the asymmetric measurement method.After processing the test data,the main parameters of blade test analysis can be obtained: the static pressure coefficient on the blade surface,the total pressure loss coefficient and the blade outlet flow angle.Finally,the energy loss,blade surface static pressure and blade outlet flow angle obtained by the CFD simulation of the blade are compared with the experimental data,and it is found that the experimental results fit well with the simulation results,and the trend is consistent.