Numerical Prediction of Thermomechanical Sensitivity of the First Stage Nozzle Guide Vane With Film Cooling

Abstract

Abstract Practically, a gas-turbine engine’s first-stage nozzle guide vane (NGV) must operate under extreme conditions induced by high temperatures from burned gases, causing severe damage to the vane, such as cracks or fatigue failures. As a result, the first stage NGV’s lifespan is shortened. In other words, the first stage NGV’s lifespan is determined by the vane material’s durability. Therefore, effective cooling systems and thermal barrier coating (TBC) are provided. This paper presents a numerical prediction of the thermomechanical sensitivity of the first stage NGV with film cooling under aerothermal conditions and TBC using a 3D CFD/CHT approach with a static structure model for a steady temperature analysis. Turbine inlet temperature (TIT), coolant inlet temperature (CIT), blowing ratio (BR), and TBC thickness, which are key factors for gas turbines’ performance improvement, are used as independent variables. An examination of vane cooling performance is presented in the first part, followed by a prediction of the thermomechanical sensitivity of the vane under the four variables in terms of von Mises equivalent stress and strain in the second part. The findings obtained from both parts show that the relationship between cooling performance and thermomechanical characteristics is sensitive to the influences of turbine inlet temperature (TIT), coolant inlet temperature, and TBC thickness. In addition, the findings indicate the role of the blowing ratio in thermal and mechanical sensitivity for the film-cooled vane.