Dynamic Analysis Of Blade-Tip Radial Clearance Of HPT Based On QAR Data

The blade tip radial clearance of high-pressure turbine has a great influence on the performance and efficiency of aero-engine,too small tip clearance leads to the friction between blade and casing,while too large clearance leads to the increase of gas flow loss and fuel consumption,therefore,it is of great significance and value to carry out clearance research and clearance optimization.In this paper,aiming at the high-pressure turbine structure of CFM56-7B engine,finite element numerical simulation was selected,the fluid-thermal-solid coupling model was established;the thermal boundary conditions required were established by combining QAR data and thermal analysis.The temperature,stress and strain distributions of high-pressure turbine blade,disk and casing under different working conditions were obtained by solving the fluid-thermal-solid coupling problem with finite element software.Based on the calculation results of radial deformation of high pressure turbine blade,disk and casing under different working conditions,the variation law of tip radial clearance in different flight phases was obtained,the influence of active clearance control on the radial deformation of the casing and tip clearance was mainly analyzed.According to the temperature,stress and strain distribution of high-pressure turbine blade under different working conditions,the Manson-Coffin model and Larson-Miller model were used to predict the fatigue and creep life of the blade respectively,the influence of cooling on the life of blade was mainly analyzed.Finally,the fatigue-creep life of the blade was obtained by the linear damage accumulation theory.The results show that the fatigue life of blade is improved and the creep life is significantly improved after cooling,the predicted fatigue-creep life is compared with the actual life,and the error rate between the life of the cooling blade and the actual life is only 4.43%.