Serpentine platform cooling structures

1. A platform comprising:

a platform cooling apparatus comprising a cooling passage comprising a channel disposed at least partially through the platform and configured to conduct cooling air,

wherein the cooling passage comprises a serpentine portion comprising a first plurality of folded channels comprising at least one turn;

wherein the platform cooling apparatus further comprises an outflow aperture comprising an orifice extending in fluidic communication between the cooling passage of the platform cooling apparatus and through at least a portion of the platform and in fluidic communication with a surrounding ambient environment immediately proximate to a surface of the rotor blade;

a cooling cover apparatus at least partially fluidically sealing the platform cooling apparatus; and

a defined gap comprising an opening between the cooling cover apparatus and the platform

whereby the cooling air may escape from the cooling passage.

2. The platform according to claim 1 , wherein the platform cooling apparatus further comprises:

an inflow channel configured to receive the cooling air from a cooling cavity of an airfoil section and convey it to the cooling passage.

3. The platform according to claim 2 , further comprising heat transfer enhancement features disposed within the cooling passage.

4. The platform according to claim 1 , wherein the folded channels comprise parallel folded channels and wherein the at least one turn comprises a 180-degree turn.

5. The platform according to claim 2 , further comprising

a rib disposed between the folded channels.

6. The platform according to claim 5 , wherein the cooling passage further comprises a terminal portion comprising an end of the cooling passage forming a terminus of the cooling passage.

7. The platform according to claim 6 , wherein the platform cooling apparatus further comprises outflow apertures disposed through the terminal portion of the cooling passage and connecting the cooling passage in fluidic communication with a surrounding ambient environment immediately proximate to a surface of the platform.

8. The platform according to claim 5 , further comprising a retention mechanism to retain the cooling cover apparatus in mechanical communication with the platform proximate to the platform cooling apparatus.

9. The platform according to claim 8 , wherein the retention mechanism comprises an integral formation comprising an integral joining of the cooling cover apparatus to the platform.

10. The platform according to claim 8 , wherein the cooling cover apparatus comprises a cover plate comprising a plate structure disposed radially inward of the platform cooling apparatus and configured to at least partially fluidically seal the platform cooling apparatus.

11. The platform according to claim 10 , wherein the retention mechanism comprises a weld.

12. The platform according to claim 11 , wherein the weld comprises a perimeter weld comprising welding extending around all edges of the cover plate.

13. The platform according to claim 11 , wherein the weld comprises a platform edge weld comprising welding extending along a single edge of the cover plate.

14. The platform according to claim 11 ,

wherein the weld comprises a rib weld comprising welding extending along the rib of the platform cooling apparatus and joining the rib to the cover plate.

15. A rotor blade comprising:

a blade airfoil section comprising a cooling cavity; and

a platform comprising:

a platform cooling apparatus comprising a cooling passage comprising a channel disposed at least partially through the platform and comprising an inflow channel in fluidic communication with the cooling cavity and the cooling passage;

wherein the cooling passage further comprises an outflow aperture comprising an orifice extending in fluidic communication between the cooling passage of the platform cooling apparatus and through at least a portion of the platform and in fluidic communication with a surrounding ambient environment immediately proximate to a surface of the rotor blade;

a cooling cover apparatus at least partially fluidically sealing the platform cooling apparatus; and

a defined gap comprising an opening between the cooling cover apparatus and the platform whereby the cooling air may escape from the cooling passage.

16. A rotor blade according to claim 15 , wherein the platform further comprises heat transfer enhancement features disposed within the cooling passage.

17. A method of forming a platform comprising:

forming a platform cooling apparatus comprising a cooling passage comprising a channel disposed at least partially through the platform and configured to conduct cooling air,

wherein the cooling passage comprises a serpentine portion comprising a first plurality of folded channels comprising at least one turn;

wherein the cooling passage further comprises an outflow aperture comprising an orifice extending in fluidic communication between the cooling passage of the platform cooling apparatus and through at least a portion of the platform and in fluidic communication with a surrounding ambient environment immediately proximate to a surface of the rotor blade; and

forming a cooling cover apparatus at least partially fluidically sealing the platform cooling apparatus, wherein the cooling cover apparatus at least partially defines a gap comprising an opening between the cooling cover apparatus and the platform whereby the cooling air may escape from the cooling passage.