Thermo-mechanical loads and creep life assessment for coated turbine blades considering the influence of cooling hole blockage

Cooling hole blockage significantly impacts the service life of coated high-pressure turbine blades in aero-engines. In this study, two blockage structures reflecting the actual blockage morphology were designed. The thermo-mechanical loads of blades with and without blockage were analyzed using the shell conduction method and the Chaboche constitutive model. Combined with creep life assessment through the Larson-Miller parameter method, the fundamental reasons for the impact of blockage on the blade creep life were revealed. A creep life correction method based on the blockage damage coefficient was established to quantify the reduction in blade life reserve caused by blockage. The results indicate that blockage alters the flow field and heat transfer characteristics, decreasing cooling efficiency across most areas of the blade surface and ultimately reducing creep life. Under the specific blockage condition in this study, the critical area of the blade is located at the edge of the cooling hole near the blade root along the leading edge, with the creep life decreasing by 18.7 % and the blockage damage coefficient of 81.3 %. The research has significant scientific value for the life extension design and maintenance strategy of turbine blades.