Porosity-driven aerothermal-mechanical coupling for high-performance transpiration-cooled turbine blades

The increasing turbine inlet temperature, driven by demands for higher gas turbine efficiency, necessitates more advanced cooling solutions for turbine blades. Transpiration cooling has emerged as a highly promising approach due to its superior cooling efficiency. However, prior research on turbine blade transpiration cooling primarily focused on aerothermal performance. This study presents a comprehensive assessment of the aerothermal-mechanical properties of transpiration-cooled turbine vanes with porous media walls. We developed an innovative aerothermal-mechanical numerical framework for transpiration-cooled turbine blade simulations. Validation against experimental data demonstrates that the modified numerical approach reduces the mean average error in wall temperature predictions by up to 61% compared to conventional methods. Systematic studies have illustrated that key parameters including porosity, particle diameter and injection ratio have a combined effect on cooling effectiveness and mechanical reliability. Results show that smaller particle diameters and lower porosity enhance convective heat transfer within the porous matrix, achieving cooling effectiveness up to 0.65 at a 1.8% injection ratio. The optimal injection ratio for maximum cooling efficiency varies between 0.9% and 1.8%, depending on the porous parameters. Mechanical simulations further establish that cooling effectiveness directly correlates with thermal stress, deformation magnitude, and creep-to-rupture failure risks. The insights derived from this study provide a critical foundation for the design of high-efficiency transpiration-cooled turbine blades.