Patent ID: 7351036

Claim:
A turbine airfoil, comprising: a generally elongated airfoil having a leading edge, a trailing edge, a tip section at a first end, a root coupled to the airfoil at an end generally opposite the first end for supporting the airfoil and for coupling the airfoil to a disc, and at least one cavity forming a cooling system in the airfoil; an outer wall forming the generally elongated airfoil and having at least one elbowed film cooling hole positioned in the outer wall and providing a cooling fluid pathway between the at least one cavity forming the cooling system and outside of the airfoil; wherein the at least one elbowed film cooling hole includes a first section extending from an inner surface of the outer wall into the outer wall, an elbow coupled to the first section in the outer wall, a second section attached to the elbow in the outer wall at an end of the elbow that is generally opposite to an end to which the first section is attached, and a diffusion slot attached to the second section, having an increasing width moving away from the second section, and extending to an opening in an outer surface of the outer wall, wherein cross-sectional areas of the first section, the elbow and the second section are substantially equal; wherein the second section and the diffusion slot are aligned along an axis that is positioned at an angle to the outer surface of the airfoil between about 15 degrees and about 45 degrees.