Numerical Prediction of the Heat Loads on a Film-Cooled Turbine Vane Test Case

Abstract

Abstract. The accurate prediction of thermal loads on film-cooled turbine airfoils remains a key challenge for computational fluid dynamics due to the complex interaction between coolant injection, turbulent mixing, and boundary-layer transition. In this work, a numerical investigation of film cooling on the VKI LS-89 turbine vane is carried out under engine-representative transonic conditions, including a freestream turbulence intensity of 15%, an exit Mach number equal to 0.7, and a coolant-to-mainstream blowing ratio of 0.5. Several modeling strategies are evaluated, including wall-resolved large eddy simulation (LES), fully resolved Reynolds-averaged Navier–Stokes (RANS) simulations employing different turbulence closures, and a simplified injection region RANS approach aimed at reducing computational cost. The analysis combines spanwise-averaged quantities with two-dimensional surface distributions to provide a complete benchmark of model performance. LES provides the most reliable representation of adiabatic effectiveness, while RANS-based approaches exhibit intrinsic limitations related to turbulent mixing. Heat transfer is generally overpredicted by RANS, whereas LES accuracy is affected by transition modeling. Overall, this study provides a comprehensive benchmark of numerical approaches applied to a complex and representative turbine vane film cooling configuration, highlighting their strengths and limitations for engineering-oriented computational fluid dynamics (CFD) analyses. Its outcome highlights the need for further developments in both RANS-based and transition-sensitive scale-resolving modeling strategies for film-cooled turbomachinery applications.