Turbine airfoil tip shelf and squealer pocket cooling

An airfoil comprising:

• a pressure surface and a suction surface extending from a root section of the airfoil to a tip section of the airfoil;
• a leading edge and a trailing edge defining a chord length of the airfoil therebetween;
• and
• a tip shelf formed along the tip section of the airfoil between the pressure surface and a tip shelf wall, wherein the tip shelf wall is spaced between the pressure surface and the suction surface, wherein the tip shelf extends from within 10% of the chord length measured from the leading edge to within 10% of the chord length measured from the trailing edge;
• wherein the tip shelf extends around the leading edge and onto the suction surface to terminate on the suction surface between the leading edge and the trailing edge of the airfoil;
• wherein the leading edge further comprises an indentation formed on the leading edge, the indentation extending along the leading edge between the root section of the airfoil and the tip section of the airfoil, and wherein the indentation intersects the tip shelf at the leading edge;
• wherein the tip shelf extends to the trailing edge of the airfoil to terminate at a downstream intersection of the pressure and suction surfaces such that the tip shelf communicates with both the pressure surface and the suction surface proximate to the trailing edge.