Washer of a combustion chamber tile of a gas turbine

1. A washer of a combustion chamber tile of a gas turbine comprising:

an annular body including a central recess having a center axis, the body including a first side and an opposite second side;

a flat contact surface arranged on the first side;

a plurality of grooved air ducts positioned on the second side and isolated from the central recess, each of the plurality of air ducts including a centerline indicating a direction of air flow through the air duct; each air duct having a first portion where the centerline extends generally radially inwardly from an outer circumference of the body toward the center axis, a third portion in a center area of the washer where the centerline extends generally axially and a second portion between the first and third portions where the centerline transitions between the first portion to the third portion.

2. The washer in accordance with claim 1 , wherein at least one of the air ducts includes a substantially semi-circular cross-section.

3. The washer in accordance with claim 1 , wherein at least one of the air ducts includes a substantially semi-elliptical cross-section.

4. The washer in accordance with claim 1 , wherein the second portion is rounded.

5. The washer in accordance with claim 1 , and further comprising a rounded intake into the first portion of at least one of the air ducts.

6. The washer in accordance with claim 1 , and further comprising a rounded transition between at least one of the air ducts and the second side.

7. The washer in accordance with claim 1 , and further comprising a projection positioned on the second side in the center area of the washer and axially extending from a radially extending portion of the second side to form a stepped shape with at least a portion of the central recess positioned in the projection, and with at least a portion of the third portion of each air duct positioned in the projection and isolated from the central recess.

8. The washer in accordance with claim 7 , and further comprising an undercut positioned at a transition between the radially extending portion of the second side and the projection.

9. The washer in accordance with claim 1 , wherein the centerlines of the first portions are arranged at a distance from the second side.

10. The washer in accordance with claim 1 , wherein, for at least one of the air ducts, the centerline of the third portion is arranged at an acute angle relative to the center axis.

11. The washer in accordance with claim 1 , wherein an outer shape of the washer is round.

12. The washer in accordance with claim 1 , wherein an outer shape of the washer is oval.

13. A fastening system for a combustion chamber of a gas turbine comprising:

an outer combustion chamber wall including a recess;

an inner combustion chamber wall positioned adjacent an inner side of the outer combustion chamber wall;

a first threaded member attached to the inner combustion chamber wall and positioned through the recess;

a second threaded member threadingly engaging the first threaded member from an outer side of the outer combustion chamber wall;

a washer positioned between the second threaded member and the outer side of the outer combustion chamber wall, the washer comprising;

an annular body including a central recess having a center axis, the body including a first side and an opposite second side;

a flat contact surface arranged on the first side;

a plurality of grooved air ducts positioned on the second side and isolated from the central recess, each of the plurality of air ducts including a centerline indicating a direction of air flow through the air duct; each air duct having a first portion where the centerline extends generally radially inwardly from an outer circumference of the body toward the center axis, a third portion in a center area of the washer where the centerline extends generally axially and a second portion between the first and third portions where the centerline transitions between the first portion to the third portion;

wherein at least one of the first threaded member and the second threaded member is positioned through the central recess of the washer, the second threaded member engages the first side of the washer, and the second side of the washer engages the outer side of the outer combustion chamber wall.

14. The fastening system in accordance with claim 13 , and further comprising a projection positioned on the second side in the center area of the washer and axially extending from a radially extending portion of the second side to form a stepped shape with at least a portion of the central recess positioned in the projection, and with at least a portion of the third portion of each air duct positioned in the projection and isolated from the central recess.

15. The fastening system in accordance with claim 14 , and further comprising an undercut positioned at a transition between the radially extending portion of the second side and the projection.

16. The fastening system in accordance with claim 14 , wherein at least one of the air ducts includes a substantially semi-circular cross-section.

17. The fastening system in accordance with claim 14 , wherein at least one of the air ducts includes a substantially semi-elliptical cross-section.

18. The fastening system in accordance with claim 14 , and further comprising a rounded intake into the first portion of at least one of the air ducts.

19. The fastening system in accordance with claim 14 , and further comprising a rounded transition between at least one of the air ducts and the second side.

20. The fastening system in accordance with claim 14 , wherein, for at least one of the air ducts, the centerline of the third portion is arranged at an acute angle relative to the center axis.