Patent ID: 7008186

Claim:
A turbine blade comprising: an airfoil integrally joined to a supporting dovetail; said airfoil including opposite pressure and suction sidewalls extending chordally between opposite leading and trailing edges and in span from a root to a tip, an internal cooling circuit, and thermal barrier coating covering external surfaces of said airfoil pressure and suction sidewalls; said cooling circuit including a first flow passage disposed directly behind said leading edge, followed in turn by a second flow passage separated therefrom by a bridge integrally joined to said pressure and suction sidewalls; said bridge including a row of impingement apertures for discharging air from said second passage into said first passage in impingement behind said leading edge; said suction sidewall including a row of diffusion film cooling first holes extending therethrough in flow communication with said first passage, and said first holes being disposed through said suction sidewall at a compound inclination angle with a quadrilateral cross section forming a generally teardrop shaped outlet in a convex contour of said suction sidewall, with said teardrop outlet extending through said thermal barrier coating; said airfoil tip including squealer ribs extending outwardly from said pressure and suction sidewalls forming a recessed tip floor therebetween; said tip floor including rows of floor holes along both said pressure and suction sidewalls inboard of said squealer ribs; and said pressure sidewall includes an axial row of tip holes disposed below said squealer rib thereat.