Dome assembly for a multiple annular combustor

1. A dome assembly for a multiple annular combustor, comprising

(a) an annular dome plate having at least two radial domes, each of said radial domes including a plurality of circumferential openings therein;

(b) a heat shield positioned within each of said openings, said heat shield having a forward end located upstream of said dome plate and an aft end located downstream of said dome plate, wherein said forward end of said heat shield has threads formed thereon; and

(c) a retainer nut having an inner annular surface with threads formed thereon, said retainer nut threads being matingly engagable with said heat shield threads;

wherein said heat shield is mechanically attached to said dome plate by said retainer nut.

2. The dome assembly of claim 1, further comprising:

(a) an annular flange extending radially outward from said heat shield, said flange being located downstream of said threaded forward end; and

(b) an annular groove formed in an inner annular surface defining said dome plate opening;

wherein said heat shield flange rests within said groove and causes said heat shield to be drawn to a desired fit with said dome plate as said retainer nut is tightened on said heat shield forward end.

3. The dome assembly of claim 2, said heat shield further comprising a hollow centerbody extending axially downstream from one of a radially inner and outer side of said aft end.

4. The dome assembly of claim 3, further comprising cooling passages formed in said retaining nut and said heat shield flange, wherein air flowing to said dome plate is able to flow through said cooling passages and communicate with the interior of said centerbody.

5. The dome assembly of claim 3, said centerbody further comprising a non-linear wall including a first portion extending radially from said heat shield aft end, a second portion extending axially downstream away from said dome plate, a third portion again extending radially from said second portion, and a fourth portion extending axially upstream terminating adjacent said dome plate.

6. The dome assembly of claim 5, further comprising a notch in an upstream surface of said centerbody fourth portion adjacent said dome plate and a seal therebetween.

7. The dome assembly of claim 6, wherein a predetermined gap between said dome plate and said centerbody fourth portion is provided to prevent crushing of said seal.

8. The dome assembly of claim 5, further comprising:

(a) a flange extending radially from said centerbody fourth portion with a notch therein; and

(b) a pin inserted through said flange notch into said dome plate;

wherein said centerbody is prevented from rotating due to torque loads.

9. The dome assembly of claim 1, wherein said heat shield forward end is annular.

10. The dome assembly of claim 1, wherein said heat shield aft end is substantially square.

11. The dome assembly of claim 1, said heat shield further comprising a centerbody extending axially downstream from a radially outer side of said aft end.

12. The dome assembly of claim 11, said heat shield further comprising a centerbody extending axially downstream from a radially inner side of said aft end.

13. The dome assembly of claim 1, said heat shield further comprising a centerbody extending axially downstream from a radially inner side of said aft end.

14. The dome assembly of claim 1, further comprising:

(a) a ferrule within said dome plate opening for receiving an air/fuel mixer therein, said ferrule having an annular sealing flange extending radially therefrom; and

(b) a retaining ring positioned upstream of said heat shield forward end to provide a gap therebetween;

wherein said ferrule sealing flange is positioned within said gap so that said ferrule is permitted to move circumferentially and radially therein.

15. The dome assembly of claim 1, said retainer nut further comprising a plurality of lugs and slots at a forward end thereof.

16. A dome assembly for a triple annular combustor of a gas turbine engine, comprising:

(a) an annular dome plate having an outer dome, a middle dome, and an inner dome, each of said domes having a plurality of circumferentially spaced openings therein;

(b) an outer heat shield positioned within each of said outer dome openings;

(c) a middle heat shield positioned within each of said middle dome openings; and

(d) an inner heat shield positioned within each of said inner dome openings;

wherein said outer, middle, and inner heat shields each have a threaded forward end located upstream of said dome plate and an aft end located downstream of said dome plate;

(e) an outer retainer nut threadingly engaged with each of said outer heat shield forward ends;

(f) a middle retainer nut threadingly engaged with each of said middle heat shield forward ends; and

(g) an inner retainer nut threadingly engaged with each of said inner heat shield forward ends; wherein said outer, middle, and inner heat shields are mechanically attached to said dome plate by said outer, middle, and inner retaining nuts.

17. The dome assembly of claim 16, further comprising:

(a) an outer, middle, and inner ferrule within each of said outer, middle, and inner dome openings, respectively, for receiving air/fuel mixers therein, said outer, middle and inner ferrules each having an annular sealing flange extending radially therefrom; and

(b) a retaining ring positioned upstream of each of said outer, middle and inner heat shield forward ends to provide a gap between said retaining rings and said heat shields;

wherein said ferrule flanges are positioned within said gaps so that said outer, middle and inner ferrules are permitted to move circumferentially and radially therein.

18. The dome assembly of claim 17, wherein said ferrule flanges of said outer, middle, and inner ferrules are located at varying axial positions.

19. The dome assembly of claim 18, wherein said outer, middle, and inner heat shields have forward threaded ends of varying axial length and said retainer nuts are of corresponding axial length.

20. The dome assembly of claim 16, said triple annular combustor including an outer liner affixed to a radially outer end of said dome plate and an inner liner affixed to a radially inner end of said dome plate, wherein said outer heat shields include a centerbody extending axially downstream from an outer radial side thereof to insulate said outer liner, said inner heat shields include a centerbody extending axially downstream from an inner radial side thereof to insulate said inner liner, and said middle heat shields include a first centerbody extending axially downstream from an outer radial side thereof to separate said outer and middle domes and a second centerbody extending axially downstream from an inner radial side thereof to separate said middle and inner domes.