Effect of thermal barrier coatings and integrated cooling on the conjugate heat transfer and thermal stress distribution of nickel-based superalloy turbine vanes

Based on the comprehensive design of the thermal barrier coatings (TBCs) and advanced integrated cooling systems for the Ni-based superalloy turbine vanes. This study employs a multidisciplinary method to research the aerothermal performance and elastic thermal stress of the first stage Ni-based superalloy (DS GTD 111) turbine guide vane cooled by an integrated cooling system and TBC thickness of 0.5 mm. The results show that the highest temperature and average temperature on the substrate under TBC decreased by 126 K and 110 K, respectively. For the vanes without and with TBC, the thermal stresses are concentrated on the midchord region of the suction side, the upper edge of film holes outflow, and junction regions between the vane root, tip, and endwalls, which bear high-temperature gradient and high temperature. However, TBC reduces stress value by 50%similar to 95% in thermal stress concentration regions of the substrate, which significantly reduces the slip systems activated regions on the substrate. In addition, the activation of the dominant slip system (DSS) is a further optimization objective for cooling turbine vanes. This study provides macroscopic and microscopic perspectives for improving integrated cooling structures of actual vanes in the design process by comprehensively considering aerothermal and thermomechanical performance.

Automated summary

Based on a multidisciplinary method, this study investigates the aerothermal performance and thermal stress of the first stage Ni-based superalloy turbine guide vane. The results show that the thermal barrier coating (TBC) reduces the highest and average temperatures on the substrate by 126 K and 110 K, respectively. The TBC also significantly reduces stress concentrations and activated slip systems on the substrate, improving the thermomechanical performance of the vane.