Method and apparatus for cooling a wall within a gas turbine engine

• US 6,254,334 B1
• Filed: 10/05/1999
• Issued: 07/03/2001
• Est. Priority Date: 10/05/1999
• Status: Expired due to Term

• Current Assignee: United Technologies Corporation (Rtx Corporation)
• Original Assignee: United Technologies Corporation (Rtx Corporation)
• Inventors: LaFleur, Ronald S.
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): McAleenan, James M.
• Application Number:
  US09/412,274
• Time in Patent Office: 637 Days
• Field of Search: 415/115, 416/97.R, 416/97.A, 416/96.R
• US Class Current: 415/115
• CPC Class Codes: F01D 25/12 Cooling
• CPC Class Codes: F01D 5/186 Film cooling F01D5/187 takes precedence
• CPC Class Codes: F01D 5/187 Convection cooling
• CPC Class Codes: F05D 2260/202 by film cooling
• 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

According to the present invention, a method and an apparatus for cooling a wall within a gas turbine engine is provided. The apparatus includes and the method provides for a cooling circuit disposed within a wall having utility within a gas turbine engine. The cooling circuit includes a forward end, an aft end. The pedestals extend between first and second portions of the wall. The characteristics and array of the pedestals within the cooling circuit are chosen to provide a heat transfer cooling profile within the cooling circuit that substantially offsets the profile of the thermal load applied to the wall portion containing the cooling circuit. At least one inlet aperture provides a cooling airflow path into the forward portion of the cooling circuit from the cavity. A plurality of exit apertures provide a cooling airflow path out of the aft portion of the cooling circuit and into the core gas path outside the wall.

Claims

1. A coolable airfoil, comprising:

a body having a wall;

a cavity surrounded by said wall;

at least one cooling circuit disposed in said wall, said cooling circuit having a length extending between a forward end and an aft end, and a width extending between a pair of sides, wherein said cooling circuit includes;

a first wall portion;

a second wall portion;

a plurality of first pedestals extending between said first wall portion and said second wall portion;

an inlet aperture disposed in said wall, providing a cooling air flow path between said cavity and said forward end of said cooling circuit; and

a plurality of exit apertures disposed in said second wall portion, providing a cooling air flow path between said aft end of said cooling circuit and outside said wall;

wherein said cooling circuit has a flow area within a plane extending widthwise across said cooling circuit, and wherein said flow area progressively decreases within said cooling circuit from said inlet aperture to said exit apertures.

2. The coolable airfoil of claim 1, wherein said first pedestals are substantially uniform in cross-section and arranged in widthwise extending rows, and beginning with a first said row closest to said inlet aperture, each subsequent row downstream of said first row includes a number of said first pedestals that is equal to or greater than the number of said first pedestals in an upstream row.

3. The coolable airfoil of claim 1, wherein said first pedestals are arranged in widthwise extending rows, and beginning with a first row closest to said inlet aperture, each said first pedestal within each subsequent said row downstream of said first row has a width greater than or equal to said first pedestals within an upstream row.

4. The coolable airfoil of claim 1, further comprising:

a row of alternately disposed second pedestals and third pedestals located along said aft end of said cooling circuit, wherein said exit apertures are formed between said second and third pedestals and said first and second wall portions.

5. A cooling circuit disposed within a wall, said cooling circuit comprising:

a passage having a first end, a second end, and a width, said passage disposed between a first wall portion and a second wall portion;

a plurality of pedestals disposed within said passage, extending between wall portions;

an inlet aperture, providing a cooling air flow path between a first side of wall and said first end of said passage; and

a plurality of exit apertures extending through said second wall portion, providing a cooling air flow path between said second end of said passage and a second side of said wall;

wherein said cooling circuit has a flow area within a plane extending widthwise across said passage, and wherein said flow area decreases within said cooling circuit from said inlet aperture to said exit apertures.

6. The cooling circuit of claim 5, further comprising:

a row of alternately disposed second pedestals and third pedestals located along said aft end of said cooling circuit, wherein said exit apertures are formed between said second and third pedestals and said first and second wall portions.

7. A method for cooling a wall comprising the steps of:

(a) providing a cooling circuit within said wall, said cooling circuit including;

a passage having a first end, a second end, and a width, said passage disposed between a first wall portion and a second wall portion;

a plurality of first pedestals disposed within said passage, extending between wall portions;

an inlet aperture that provides a cooling air flow path between a first side of wall and said first end of said passage; and

a plurality of exit apertures that extend through said second wall portion and provide a cooling air flow path between said second end of said passage and a second side of said wall;

(b) providing operating conditions that include a thermal load profile adjacent said cooling circuit to which said wall is likely to be exposed; and

(c) selectively tuning said cooling circuit to provide a heat transfer profile under said operating conditions that substantially offsets said thermal load profile adjacent said cooling circuit.

8. The method of claim 7, wherein said cooling circuit includes a flow area within a plane extending widthwise across said passage, and said cooling circuit is selectively tuned by arranging said pedestals in a way that decreases said flow area, consequently increasing said heat transfer to offset the local thermal load.

9. The method of claim 7, wherein said pedestals are substantially similar in cross-section and said pedestals are arranged in rows and said flow area is decreased by increasing the number of first pedestals in one or more of said rows.

10. The method of claim 7, wherein said pedestals are arranged in rows and said flow area is decreased by increasing the width of said first pedestals in one or more of said rows.

11. A hollow airfoil having a cavity surrounded by a wall, comprising:

at least one cooling circuit disposed in said wall between a first and a second portion of said wall, said cooling circuit having a forward end, an aft end, a width that extends between a pair of sides, a plurality of first pedestals extending between said first wall portion and said second wall portion, an inlet aperture disposed in said wall that provides a cooling air flow path between said cavity and said forward end of said cooling circuit, and a plurality of exit apertures disposed in said second wall portion that provide a cooling air flow path between said aft end of said cooling circuit and outside said wall;

wherein said cooling circuit has a flow area within a plane extending widthwise across said cooling circuit, and wherein said flow area decreases within said cooling circuit from said inlet aperture to said exit apertures.

12. A cooling circuit disposed within a wall, said cooling circuit comprising:

a passage having a first end, a second end, and a width, said passage disposed between a first wall portion and a second wall portion;

a plurality of first pedestals disposed within said passage, extending between wall portions;

a plurality of T-shaped second pedestals;

a third pedestals of third pedestals, wherein said pedestals and said third pedestals are alternately disposed and said third pedestals nest between adjacent second pedestals;

an inlet aperture, providing a cooling air flow path between a first side of wall and said first end of said passage; and

a plurality of exit apertures extending through said second wall portion providing a cooling air flow path between said second end of said passage and a second side of said wall, said exit apertures formed between said second pedestals and said third pedestals.