EFFECTS OF WALL TEMPERATURE ON TRANSONIC GAS TURBINE AEROTHERMODYNAMICS: A WALL-MODELED LES STUDY

This paper explores the impact of wall temperature on the performance of transonic gas turbine stators. Wall-modeled Large Eddy Simulations (LES) combined with the immersed boundary method are used in conjunction with modern multiGPU acceleration of Navier-Stokes equations. Six wall-to-recovery temperature ratios are analyzed, from adiabatic to highly cooled conditions, and the time-varying behavior of the system, including low-frequency components, is examined. Findings show that cooler walls affect flow dynamics, particularly by reducing turbulence intensity and increasing aerodynamic losses. Stronger cooling is found to lower energy transfer from the outer flow to the blade boundary layer, altering wake behavior and turbulence length scales. Consequently, cooler wall conditions expand the wake region, impact the stability of the boundary layer, and contribute to greater aerodynamic inefficiencies. Through the use of advanced scale-resolved simulations, such as wall-modeled LES, the research sheds light on the physics of these devices, offering valuable insights that can inform the optimization of cooling strategies in gas turbine technology.