Turbine blade tip cooling system

1. A turbine blade, comprising:

a generally elongated blade having a leading edge, a trailing edge, a tip wall at a first end, a root coupled to the blade at an end generally opposite the first end for supporting the blade and for coupling the blade to a disc, and at least one cavity forming a cooling system in the blade;

at least one elongated tip cooling chamber forming a portion of the cooling system and at least partially defined by the tip wall proximate to the first end,

wherein an inner surface of the tip wall includes a plurality of curved bumper protrusions extending from the inner surface radially inward toward the root; and

wherein a throat section extending between a first forwardmost curved bumper protrusion and a second immediately adjacent downstream curved bumper protrusion is offset radially outward from an inner tip surface, thereby creating a first recessed tip slot having a reduced tip wall thickness.

2. The turbine blade of claim 1 , wherein the cooling system includes a plurality of ribs generally aligned with the trailing edge and wherein the curved bumper protrusions extending radially inward from the inner surface of the tip wall are offset in a chordwise direction relative to the ribs.

3. The turbine blade of claim 1 , wherein the first recessed tip slot is positioned proximate to a row of ribs.

4. The turbine blade of claim 1 , further comprising a rib extending radially from an outer surface of the tip of the generally elongated blade and at a perimeter of the blade such that a pocket is formed within the rib on the outer surface of the tip wall of the generally elongated blade.

5. The turbine blade of claim 4 , wherein the rib extending radially from an outer surface of the tip of the generally elongated blade is discontinuous such that a portion of the rib on a pressure side terminates upstream from the trailing edge while a portion of the rib on a suction side terminates at the trailing edge, thereby forming a pressure side slot in the pocket on the outer surface of the tip wall of the generally elongated blade.

6. The turbine blade of claim 1 , wherein a throat section extending between the second curved bumper protrusion and a third immediately adjacent downstream curved bumper protrusion is offset radially outward from an inner tip surface, thereby creating a second recessed tip slot having a reduced tip wall thickness.

7. The turbine blade of claim 6 , wherein the first recessed tip slot is positioned proximate to a row of ribs, and the second recessed tip slot is positioned proximate to another row of ribs.

8. The turbine blade of claim 7 , further comprising a rib extending radially from an outer surface of the tip of the generally elongated blade and at a perimeter of the blade such that a pocket is formed within the rib on the outer surface of the tip wall of the generally elongated blade.

9. The turbine blade of claim 8 , wherein the rib extending radially from an outer surface of the tip of the generally elongated blade is discontinuous such that a portion of the rib on a pressure side terminates upstream from the trailing edge while a portion of the rib on a suction side terminates at the trailing edge, thereby forming a pressure side slot in the pocket on the outer surface of the tip wall of the generally elongated blade.

10. The turbine blade of claim 1 , further comprising a rib extending radially from an outer surface of the tip of the generally elongated blade and at a perimeter of the blade such that a pocket is formed within the rib on the outer surface of the tip wall of the generally elongated blade.

11. The turbine blade of claim 10 , wherein the rib extending radially from an outer surface of the tip of the generally elongated blade is discontinuous such that a portion of the rib on a pressure side terminates upstream from the trailing edge while a portion of the rib on a suction side terminates at the trailing edge, thereby forming a pressure side slot in the pocket on the outer surface of the tip wall of the generally elongated blade.

12. A turbine blade, comprising:

a generally elongated blade having a leading edge, a trailing edge, a tip wall at a first end, a root coupled to the blade at an end generally opposite the first end for supporting the blade and for coupling the blade to a disc, and at least one cavity forming a cooling system in the blade;

at least one elongated tip cooling chamber forming a portion of the cooling system and at least partially defined by the tip wall proximate to the first end,

wherein an inner surface of the tip wall includes a plurality of curved bumper protrusions extending from the inner surface radially inward toward the root;

wherein the cooling system includes a plurality of ribs generally aligned with the trailing edge and wherein the curved bumper protrusions extending radially inward from the inner surface of the tip wall are offset in a chordwise direction relative to the ribs; and

wherein a throat section extending between a first forwardmost curved bumper protrusion and a second immediately adjacent downstream curved bumper protrusion is offset radially outward from an inner tip surface, thereby creating a first recessed tip slot having a reduced tip wall thickness.

13. The turbine blade of claim 12 , wherein the first recessed tip slot is positioned proximate to a row of ribs.

14. The turbine blade of claim 12 , further comprising a rib extending radially from an outer surface of the tip of the generally elongated blade and at a perimeter of the blade such that a pocket is formed within the rib on the outer surface of the tip wall of the generally elongated blade.

15. The turbine blade of claim 14 , wherein the rib extending radially from an outer surface of the tip of the generally elongated blade is discontinuous such that a portion of the rib on a pressure side terminates upstream from the trailing edge while a portion of the rib on a suction side terminates at the trailing edge, thereby forming a pressure side slot in the pocket on the outer surface of the tip wall of the generally elongated blade.

16. The turbine blade of claim 12 , wherein a throat section extending between the second curved bumper protrusion and a third immediately adjacent downstream curved bumper protrusion is offset radially outward from an inner tip surface, thereby creating a second recessed tip slot having a reduced tip wall thickness.

17. The turbine blade of claim 16 , wherein the first recessed tip slot is positioned proximate to a row of ribs, and the second recessed tip slot is positioned proximate to another row of ribs.

18. A turbine blade, comprising:

a generally elongated blade having a leading edge, a trailing edge, a tip wall at a first end, a root coupled to the blade at an end generally opposite the first end for supporting the blade and for coupling the blade to a disc, and at least one cavity forming a cooling system in the blade;

at least one elongated tip cooling chamber forming a portion of the cooling system and at least partially defined by the tip wall proximate to the first end,

wherein an inner surface of the tip wall includes a plurality of curved bumper protrusions extending from the inner surface radially inward toward the root;

wherein the cooling system includes a plurality of ribs generally aligned with the trailing edge and wherein the curved bumper protrusions extending radially inward from the inner surface of the tip wall are offset in a chordwise direction relative to the ribs;

wherein a throat section extending between a first forwardmost curved bumper protrusion and a second immediately adjacent downstream curved bumper protrusion is offset radially outward from an inner tip surface, thereby creating a first recessed tip slot having a reduced tip wall thickness;

wherein the first recessed tip slot is positioned proximate to a row of ribs;

a rib extending radially from an outer surface of the tip of the generally elongated blade and at a perimeter of the blade such that a pocket is formed within the rib on the outer surface of the tip wall of the generally elongated blade; and

wherein the rib extending radially from an outer surface of the tip of the generally elongated blade is discontinuous such that a portion of the rib on a pressure side terminates upstream from the trailing edge while a portion of the rib on a suction side terminates at the trailing edge, thereby forming a pressure side slot in the pocket on the outer surface of the tip wall of the generally elongated blade.

19. The turbine blade of claim 18 , wherein a throat section extending between the second curved bumper protrusion and a third immediately adjacent downstream curved bumper protrusion is offset radially outward from an inner tip surface, thereby creating a second recessed tip slot having a reduced tip wall thickness, and wherein the first recessed tip slot is positioned proximate to a row of ribs, and the second recessed tip slot is positioned proximate to another row of ribs.