Teardrop film cooled blade

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.