关键词: 高压涡轮;性能试验;近壁边界层模型;测试布局;等熵效率

Abstract: It is believed that the blockage caused by the geometry of probes, insufficient probes at the measured surface of inlet/exit and the missing of flow information in end wall roughly affect the accuracy of isentropic efficiency in the steady performance experiment of turbine. The calculation model of total temperature and total pressure near the end wall is proposed in this work, which is based on the assumption that the distribution of velocity of boundary layer near the end wall at the turbine exit is similar to flat plate turbulent boundary layer’s. According to the numerical analysis of the single-state high-pressure turbine (PW E³), it is found that the accuracy of isentropic efficiency in the turbine experiment increases greatly due to the application of the calculation model. And the turbine efficiency accuracy is highest when the probe near the hub is in the range of 5% to 10% blade height and the probe near the tip is in the range of 90% to 95% blade height. When the measured surface is located downstream of the triple axial chord length of rotor root at the turbine exit, the errors between corrected isentropic efficiency and numerical results are below 0.3% in different conditions. The model mentioned above is used to further study the effects of circumferential and radial probe number on the turbine efficiency. The results show that the least circumferential probes can be 5 and optimal number of radial probes can be 7 to 10 to meet the requirement of the efficiency accuracy in the experiment. It can be concluded that the obtained post-processing method of experiment data and the criteria of rake measurements can be used in the experimental design of turbine performance and post-processing of experiment data in engineering application.

Key words: High pressure turbine;Performance experiment;Boundary layer model near the end wall;Rake measurements;Isentropic efficiency