TURBINE AIRFOIL COOLING SYSTEM WITH LEADING EDGE DIFFUSION FILM COOLING HOLES

摘要

A turbine airfoil (10) usable in a turbine engine and having an internal cooling system (14) with one or more diffusion film cooling holes (16) with an exhaust outlet (18) positioned at the stagnation line (20) at the leading edge (22) and configured to exhaust cooling fluid to the pressure and suction sides (24, 26) of the airfoil (10) is disclosed. The diffusion film cooling hole (16) may be formed from a first section (28) having a generally constant cross-section and a second section (30) extending outward from the first section (28) with a diverging cross-sectional area. The exhaust outlet (18) of the diffusion film cooling hole (16) may include a curved side that follows the curvature of the outer surface (34) at the leading edge (22). In at least one embodiment, the turbine airfoil (10) may include a showerhead (36) at the leading edge (22) formed from a single row (38) of diffusion film cooling holes (16) that exhaust cooling fluid to the pressure and suction sides (24, 26) of the airfoil (10).