Thermo-mechanical behavior and creep life analysis of TBC-coated turbine guide vanes considering the influence of film cooling hole blockage

Blockage of film cooling holes is an unavoidable degradation mechanism in high-pressure turbine guide vanes. In this study, a thermal-fluid-solid coupled numerical framework is developed to systematically investigate the influence of pressure-surface film cooling hole blockage on the thermo-mechanical response and creep life of TBC-coated turbine guide vanes. Six blockage ratios are considered to quantify their impacts on film-cooling effectiveness, temperature distribution, equivalent stress, and substrate creep life. The results show that increasing the blockage ratio leads to a clear reduction in film-cooling effectiveness, with a maximum decrease of about 17%. Under the maximum blockage condition, the average temperature of the vane substrate increases by approximately 24 K compared with the unblocked case. Temperature redistribution further drives the expansion of thermal stress concentration zones from the localized leading-edge region toward the downstream pressure surface. Creep life predictions show that film cooling hole blockage significantly accelerates creep damage accumulation in the substrate, leading to a maximum creep life reduction of about 5% in this study. The findings provide useful guidance for the design, maintenance, and repair of TBC-coated turbine guide vanes in engineering practice.