Abstract
This study deals with the investigation of thermal and aerodynamic performance of film cooling over the leading edge of a high-pressure turbine blade for gas turbines. A large-scaled test model of a typical leading edge with cooling holes is constructed by use of acrylic-resin semi-circular cylinder and flat plates to obtain experimental data. In this study, film effectiveness and heat transfer coefficient over the leading edge are measured by a transient method using thermochromic liquid crystal, where the secondary air is heated. As for the film effectiveness, a comb-like thermo-probe consisting of a number of thermocouples is also employed to acquire the quasi-adiabatic wall temperature as well as spatial distributions of the secondary air temperature on each of the traverse planes normal to the model surface. The steady-state flow field around and inside the test model, including the plenum chamber, is reproduced by RANS (Raynolds-Averaged Navier-Stokes) solvers. A commercial CFD solver, ANSYS Fluent, is used in this study. DES (Detached Eddy Simulation) based on Spalart-Allmaras model is also applied to the simulation. Film effectiveness distributions are numerically investigated using RANS and DES approaches and compared with the experiments. It follows that DES shows better agreements with the experiment than RANS simulation.
