HIGH EFFICIENCY FAN COOLING HOLES FOR TURBINE AIRFOIL

摘要

A turbine airfoil (32) includes a leading edge (36) and an axially spaced-parttrailing edge (38), the leading edge (36) having an axially-extending externalsurfacecurvature. A cooling circuit (50) in the airfoil includes cooling holes (60)formed inthe leading edge (36) along the span axis of the airfoil. The cooling holes(60) have adiffuser section communicating with the leading edge (36) surface. Thediffusersection has four opposed walls defining a generally quadralinear exit openingon thesurface of the leading edge (36). One of the diffuser walls has a convexcurvature thatapproximates the external surface curvature of the leading edge (36) wherebyfluidflow from the cooling hole exits is evenly dispersed and spread along landportions ofthe leading edge (36) adjacent the cooling holes (60).