Coupling method and structure for a propulsion system hot section

1. A method of coupling a flameholder assembly to an afterburning exhaust section of a propulsion system, wherein the propulsion system includes an outer casing and an inner casing defining a flameholder assembly disposed radially within the outer casing, the method comprising:

providing a housing defining a groove, and a retaining rod within the groove to which a structural member attaches;

providing a retaining plate defining an opening through which the structural member is extended;

coupling the structural member to the retaining rod of the housing and the outer casing of the propulsion system; and

coupling the retaining plate to the housing and the inner casing of the propulsion system such that the structural member is retained by the retaining rod of the housing and the retaining plate, the retaining plate at least partially surrounding the structural member within the groove.

2. The method of claim 1 , wherein coupling the retaining plate to the housing includes fastening the retaining plate to the housing via a mechanical fastener through a coupling member attached to the inner casing of the propulsion system.

3. The method of claim 1 , wherein coupling the structural member to the retaining rod of the housing couples the flameholder assembly to an outer casing of the propulsion system.

4. The method of claim 1 , wherein coupling the retaining plate to the housing and the inner casing comprises:

wherein the inner casing is a first inner casing;

providing a second inner casing radially outward of the first inner casing;

providing a spacer between the retaining plate and the first inner casing, wherein the retaining plate is coupled to the housing; and

coupling the housing to the second inner casing, wherein coupling the housing to the second inner casing couples the flameholder assembly to the outer casing.

5. The method of claim 1 , wherein coupling the retaining plate to the housing defines a load path through the inner casing, a spacer, and the retaining plate via a mechanical fastener.

6. The method of claim 1 , wherein coupling the structural member to the retaining rod of the housing and the outer casing of the propulsion system defines a load path through the retaining rod of the housing, the structural member at a first end coupled to the retaining rod, and the structural member at a second end coupled to the outer casing of the propulsion system.

7. The method of claim 1 , wherein coupling the structural member to the retaining rod provides an axis of rotation generally tangent to a circumferential direction around an axial centerline of the propulsion system, and wherein the structural member is restricted from displacement along the axis of rotation.

8. The method of claim 7 , wherein coupling the structural member to the retaining rod restricts displacement of the flameholder assembly along the longitudinal direction of the propulsion system.

9. A propulsion system comprising a compressor section, a combustion section, a turbine section, and an afterburning exhaust section in serial arrangement and generally surrounded by an outer casing extended along a longitudinal distance of the propulsion system, wherein the propulsion system further comprises:

a flameholder assembly disposed in the afterburning exhaust section, the flameholder assembly comprising:

a housing defining a groove, and a retaining rod within the groove;

a structural member defining a first end and a second end, wherein the first end defines a first coupling member coupled to the retaining rod of the housing, and wherein the second end defines a second coupling member coupled to the outer casing;

a retaining plate coupled to the housing, wherein the retaining plated defines an opening through which the structural member is extended; and

wherein the first end of the structural member is retained within the groove of the housing by the retaining rod of the housing and the retaining plate, and wherein the retaining plate at least partially surrounds the first end of the structural member within the groove.

10. The propulsion system of claim 9 , wherein the first end of the structural member is retained between the retaining rod and the retaining plate.

11. The propulsion system of claim 10 , wherein the flameholder assembly further comprises a third coupling member attached to an inner casing, and wherein the flameholder assembly comprises a spacer disposed between the third coupling member and the retaining plate, wherein a mechanical fastener couples together the third coupling member, the spacer, and the retaining plate.

12. The propulsion system of claim 11 , wherein the flameholder assembly defines a load path through the inner casing, the third coupling member, the spacer, and the retaining plate via the mechanical fastener.

13. The propulsion system of claim 11 , wherein the propulsion system defines a load path through the flameholder assembly, and wherein the flameholder assembly defines a load path through the retaining rod of the housing, the structural member at the first end coupled to the retaining rod, and the structural member at the second end coupled to the outer casing of the propulsion system.

14. The propulsion system of claim 9 , wherein the retaining rod defines an axis of rotation generally tangent to a circumferential direction around an axial centerline of the propulsion system, and wherein the structural member is restricted from displacement along the axis of rotation.

15. The propulsion system of claim 9 , wherein the retaining rod restricts displacement of the flameholder assembly along the longitudinal direction of the propulsion system.

16. A gas turbine engine comprising a hot section defining a combustion section and a turbine section, the gas turbine engine comprising:

inner casing extended generally along the longitudinal direction and radially within the outer casing;

a coupling assembly comprising:

a housing defining a groove, and a retaining rod within the groove;

a structural member defining a first end coupled to the retaining rod;

a retaining plate coupled to the housing, wherein the retaining plated defines an opening through which the structural member is extended;

wherein the structural member is retained to the retaining rod within the groove of the housing by the retaining plate, the retaining plate at least partially surrounding the first end of the structural member within the groove;

a coupling member attached to the inner casing; and

a spacer disposed between the coupling member and the housing, wherein a mechanical fastener couples together the coupling member, the spacer, the housing, and the retaining plate.

17. The gas turbine engine of claim 16 , wherein a load path is defined through the annular flameholder casing, the coupling member, the spacer, and the retaining plate via the mechanical fastener.

18. The gas turbine engine of claim 16 , wherein the gas turbine engine defines a load path through the inner casing, the coupling member, the spacer, and the retaining plate.

19. The gas turbine engine of claim 16 , wherein the the coupling assembly is disposed in the combustion section of the engine.

20. The gas turbine engine of claim 16 , wherein the engine comprises an afterburning exhaust section, and wherein the inner casing and the outer casing each surround the afterburning exhaust section of the engine.