Gas turbine rotor disk having scallop shield feature

1. A rotor disk for a gas turbine engine, comprising:

a rim portion disposed about a central axis;

a blade post disposed proximate the rim portion, the blade post having a first branch and a second branch; and

a first scallop disposed within the rim portion, between and radially inward of the first branch and the second branch,

wherein the blade post is positioned between a first disk live and a second disk live and wherein the first disk live and the second disk live define a disk live circumferential arc and a disk live circumferential length and

wherein the first scallop defines a cutout portion having a circumferential length and a radial center.

2. The rotor disk of claim 1 , wherein the rim portion defines a forward face and an aft face and wherein the first scallop is disposed within at least one of the forward face and the aft face.

3. The rotor disk of claim 2 , wherein the first scallop defines a surface intersection where the cutout portion intersects the at least one of the forward face and the aft face.

4. The rotor disk of claim 3 , wherein the surface intersection defines one of an elliptical shape, a circular shape or a racetrack shape.

5. The rotor disk of claim 4 , wherein the surface intersection defines a plane that is perpendicular to the central axis.

6. The rotor disk of claim 1 , wherein the circumferential length is within thirty percent to fifty percent of the disk live circumferential length.

7. The rotor disk of claim 6 , wherein the cutout portion defines an axial depth that is within five percent to ten percent of the disk live circumferential length.

8. The rotor disk of claim 7 , wherein the rim portion defines a forward face and an aft face, wherein the first scallop is disposed within at least one of the forward face and the aft face, wherein the first scallop defines a surface intersection where the cutout portion intersects the at least one of the forward face and the aft face and wherein the surface intersection defines one of an elliptical shape, a circular shape or a racetrack shape.

9. The rotor disk of claim 8 , wherein the surface intersection defines a plane that is perpendicular to the central axis.

10. The rotor disk of claim 8 , wherein the radial center is positioned on the disk live circumferential arc.

11. The rotor disk of claim 1 , wherein the rim portion defines a forward face and an aft face and wherein the first scallop is disposed within the forward face and a second scallop is disposed within the aft face.

12. A rotor assembly for a gas turbine engine, comprising:

a rim disk disposed about a central axis, the rim disk including a rim portion disposed about the central axis;

a first blade post disposed proximate the rim portion, the first blade post having a first branch pair;

a second blade post disposed proximate the rim portion, the second blade post having a second branch pair and spaced circumferentially from the first blade post;

a first scallop disposed within the rim portion, between and radially inward of the first branch pair; and

a second scallop disposed with the rim portion, between and radially inward of the second branch pair,

wherein the first blade post is positioned between a first disk live and a second disk live, the second blade post is positioned between the second disk live and a third disk live, and wherein the first disk live, the second disk live and the third disk live define a disk live circumferential arc and a disk live circumferential length and

wherein the first scallop defines a first cutout portion having a first circumferential length and a first radial center and the second scallop defines a second cutout portion having a second circumferential length and a second radial center and wherein both the first circumferential length and the second circumferential length are within thirty percent to fifty percent of the disk live circumferential length.

13. The rotor assembly of claim 12 , wherein the first cutout portion defines a first axial depth that is within five percent to ten percent of the disk live circumferential length and the second cutout portion defines a second axial depth that is within five percent to ten percent of the disk live circumferential length.

14. The rotor assembly of claim 13 , wherein the rim portion defines a forward face and an aft face, wherein the first scallop is disposed within at least one of the forward face and the aft face, wherein the first scallop defines a surface intersection where the first cutout portion intersects the at least one of the forward face and the aft face and wherein the surface intersection defines one of an elliptical shape, a circular shape or a racetrack shape.

15. A gas turbine engine, comprising:

a compressor section having a compressor rotor assembly;

a combustor section; and

a turbine section having a turbine rotor assembly,

wherein at least one of the compressor rotor assembly and the turbine rotor assembly includes

a rim disk disposed about a central axis, the rim disk including a rim portion;

a blade post disposed proximate the rim portion, the blade post having a first branch and a second branch; and

a first scallop disposed within the rim portion, between and radially inward of the first branch and the second branch,

wherein the first scallop defines a cutout portion having a circumferential length, a radial length and an axial depth,

wherein the rim portion defines a forward face and an aft face and wherein the first scallop is disposed within at least one of the forward face and the aft face,

wherein the first scallop defines a surface intersection where the cutout portion intersects the at least one of the forward face and the aft face and

wherein the surface intersection defines one of an elliptical shape, a circular shape or a racetrack shape.