Blade outer seal with micro axial flow cooling system

• US 7,306,424 B2
• Filed: 12/29/2004
• Issued: 12/11/2007
• Est. Priority Date: 12/29/2004
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: United Technologies Corporation (Rtx Corporation)
• Inventors: Romanov, Dmitriy, Drake, Jeremy
• Primary Examiner(s): Nguyen, Hoang
• Application Number:
  US11/025,172
• Publication Number:
  US 20060140753A1
• Time in Patent Office: 1,077 Days
• Field of Search: 415/115, 415/116, 415/173.1, 415/173.2
• US Class Current: 415/115
• CPC Class Codes: F01D 11/08 for sealing space between rotor blade tips and stator specially-shaped blade tips therefor F01D5/20
• CPC Class Codes: F01D 25/12 Cooling
• CPC Class Codes: F05D 2240/11 Shroud seal segments
• CPC Class Codes: F05D 2260/2212 by creating turbulence
• CPC Class Codes: F05D 2260/2214 by increasing the heat transfer surface
• CPC Class Codes: F05D 2260/22141 using fins or ribs

Abstract

A turbine blade outer air seal assembly includes a hot side exposed to a combustion hot gas flow, and a back side that is exposed to a supply of cooling air. The outer air seal segment includes a trailing edge cavity and a leading edge cavity separated by a divider. The cavities are feed cooling air through a plurality of inlet openings disposed transverse to the gas flow. The cooling air enters the cavities and flows toward a plurality of outlets at the leading edge and a plurality of outlets along the trailing edge. A plurality of pedestals within each of the cavities disrupts cooling air flow to increase heat absorption capacity and to increase the surface area capable of transferring heat from the hot side.

Claims

1. A blade outer air seal assembly for a turbine engine comprising:

a plurality of interfiting blade outer air seal segments each including a leading edge, a trailing edge, two axial edges, a back side and a hot side exposed to combustion gases, wherein each of said plurality of interfiting blade air seal segments includes a cavity including a top surface and a bottom surface, said top surface disposed on a side opposite said back side, and said bottom surface comprising a side opposite said hot side exposed to combustion gases;

a plurality of outlets disposed at said leading edge and said trailing edge for exhausting cooling airflow into the flow of combustion gases; and

a plurality of pedestals extending from said top surface and said bottom surface for creating turbulent cooling air flow through said cavity.

2. The assembly as recited in claim 1, wherein said plurality of inlet openings are arranged in a row substantially parallel with said leading edge and said trailing edge.

3. The assembly as recited in claim 2, wherein said plurality of inlet openings are arranged substantially midway between said leading edge and said trailing edge.

4. The assembly as recited in claim 2, wherein said cavity includes a divider for separating cooling air flow from said inlet holes such that a portion of said cooling air flow flows toward said leading edge and another portion flows toward said trailing edge.

5. The assembly as recited in claim 4, wherein said cavity comprises a leading edge cavity and a trailing edge cavity isolated from each other by said divider, wherein a cooling capacity of said cooling air flow corresponds to heat input such that said seal assembly maintains a desired surface temperature.

6. The assembly as recited in claim 2, wherein said plurality of pedestals comprises a first plurality of pedestals arranged between said divider and said leading edge and second plurality of pedestals arranged between said divider and said trailing edge.

7. The assembly as recited in claim 6, including a third and a forth plurality of pedestals disposed along respective axial edges.

8. The assembly as recited in claim 7, wherein each of said third and fourth plurality of pedestals are isolated from any other of said pluralities of pedestals by an axial divider.

9. The assembly as recited in claim 1, wherein each of said plurality of pedestals comprises a cylindrical member.

10. The assembly as recited in claim 1, wherein each of said plurality of pedestals comprises a chevron shaped structure.

11. The assembly as recited in claim 1, wherein each of said plurality of pedestals comprises a rectangular structure.

12. The assembly as recited in claim 1, wherein each of said plurality of pedestals comprises an oval-shaped structure.

13. The assembly as recited in claim 1, wherein said plurality or pedestals comprise a tortuous path for cooling air flow.

14. A turbine blade shroud assembly for a turbine engine comprising:

a plurality of interfitting blade outer air seal segments, each of said plurality of interfitting blade outer air seal assemblies a leading edge, a trailing edge, axial edges, and a cavity including a top surface and a bottom surface, said top surface comprising a side opposite a back side, and said bottom surface comprising a side opposite a hot side exposed to combustion gases, said cavity includes a plurality of inlet openings disposed along said back side between said leading and trailing edges;

wherein said cavity comprises a leading edge cavity and a trailing edge cavity separated by a divider and a plurality of pedestals extending between said top surface and said bottom surface for creating turbulent cooling air flow through said cavity.

15. The assembly as recited in claim 14, including an axial joint between adjacent ones of said plurality of interfitting blade outer air seal segments.

16. The assembly as recited in claim 14, wherein said inlet openings are disposed to inject cooling air flow at an axial location with a greatest heat generation.

17. The assembly as recited in claim 14, including axial cavities disposed along said axial edges that are separate from said cavity.

18. A blade outer air seal segment comprising:

a leading edge;

a trailing edge;

a cool side exposed to a source of cooling air;

a hot side exposed to hot fluid flow; and

a main cavity including a top surface and a bottom surface, said top surface comprising a side opposite said cool side, and said bottom surface comprising a side opposite said hot side, wherein said main cavity is divided into a trailing edge cavity and a leading edge cavity by a divider that divides cooling air flow between said leading edge cavity and said trailing edge cavity.

19. The blade outer air seal segment recited in claim 18, including a plurality of cooling air inlets disposed to communicate air into said cavity proximate said divider.

20. The blade outer air seal segment recited in claim 18, wherein said divider comprises a castellated wall between said trailing edge cavity and said leading edge cavity, and adjacent ones of said plurality of cooling air inlets communicate air to a different one of said leading edge cavity and said trailing edge cavity.

21. The blade outer air seal segment recited in claim 18, including a plurality of pedestals extending between said top surface and said bottom surface of said cavity.

22. The blade outer air seal segment recited in claim 18, including first and second lateral edges extending between said leading edge and said trailing edge and at least one lateral cavity disposed at each of the first and second lateral edges supplied with cooling air separate from said main cavity.