Evaluation of pressure side film cooling with flow and thermal field measurements - Part I: Showerhead effects

The goal of this study was to determine how showerhead blowing on a turbine vane leading edge affects of the performance of film cooling jets farther downstream. An emphasis was placed on measurements above the surface, i.e., flow visualization, thermal field, and velocity field measurements. The film cooling performance on the pressure side of a simulated turbine vane, with and without showerhead blowing, was examined. Results presented in this paper are for low mainstream turbulence; high mainstream turbulence effects are presented in the companion paper. At the location of the pressure side row of holes, the showerhead coolant extended a distance of about 3 d from the surface I'd is the coolant hole diameter). The pressure side was found to be subjected to high turbulence levels caused by the showerhead injection. Results indicate a greater dispersion of the pressure side coolant jets with showerhead flow due to the elevated turbulence levels.