Turbine airfoil tip shelf and squealer pocket cooling

A gas turbine engine blade comprising:

• an airfoil comprising suction and pressure surfaces extending from a root section to a tip section and from a leading edge to a trailing edge, the leading and trailing edges defining a chord length therebetween;
• a tip shelf defining an open perimeter recess between the pressure surface and a tip shelf wall, wherein the tip shelf wall is spaced between the suction surface and the pressure surface, wherein the open perimeter recess extends from the leading edge of the airfoil to the trailing edge of the airfoil,
• wherein the tip shelf extends to an intersection of the pressure surface and the suction surface at the trailing edge such that the tip shelf communicates with both the pressure surface and the suction surface proximate to the trailing edge, and
• 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;
• and
• a squealer pocket defining a closed perimeter recess between the tip shelf wall and a squealer tip wall extending congruently from the suction surface, wherein the closed perimeter recess extends from a region within 5% of the chord length measured from the leading edge of the airfoil to terminate in a region between 25% and 80% of the chord length measured from the trailing edge of the airfoil.

An airfoil for a gas turbine engine, the airfoil comprising:

• pressure and suction surfaces extending from a root section to a tip section;
• leading and trailing edges defining a chord length therebetween;
• a squealer tip cavity extending along the tip section of the airfoil, the squealer tip cavity defined between a squealer tip wall extending congruently from the suction surface and a tip shelf wall extending between the squealer tip wall and the pressure surface, wherein the squealer tip cavity extends from a location within 10% of the chord length measured from the leading edge of the airfoil and terminates at a location less than 85% of the chord length measured from the trailing edge;
• and
• a tip shelf recess formed between the tip shelf wall and the pressure surface of the airfoil, the tip shelf recess extending from the leading edge of the airfoil 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, and
• 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.