Investigation of creep life optimization of a high-pressure turbine rotor blade with ribbed internal cooling channels

This study has performed numerical optimization on the creep life of a high-pressure turbine rotor blade featuring internal serpentine cooling channels operating under elevated temperature and rotational speed conditions. A gas-thermal-structural coupled analysis approach with the γ- Re_θ transition shear stress transport turbulence model was employed, solving three-dimensional compressible turbulent airflow, thermal, and stress equations. Thereafter, a multi-objective optimization algorithm was utilized to obtain the Pareto optimization front by adjusting the width of the internal cooling channels. The creep rupture failure lifespan of the turbine blade was estimated using the Mason–Succop model. We examined the flow field and heat transfer characteristics within the internal ribbed channels, temperature, thermal and centrifugal stress distributions, and lifespan at various cross-sections for the baseline and two optimized cases, taking into account the rib and compensation hole geometry. Our results indicate overheating regions near the tip and root, characterized by a significantly nonuniform temperature pattern on the original blade wall. Notably, the minimum creep life was found at the trailing edge close to the blade root, attributed to relatively high centrifugal tensile stress and temperature. Compared with the baseline, the optimized turbine blade achieved a 15 K reduction in the average temperature of the blade wall and a 75% improvement in creep life at the mid-span, maintaining a 0.3% reduction in cooling mass flow.