COOLED AEROFOIL FOR A GAS TURBINE ENGINE

• US 20100254801A1
• Filed: 02/16/2010
• Published: 10/07/2010
• Est. Priority Date: 04/03/2009
• Status: Active Grant

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: TIBBOTT, Ian
• Granted Patent: US 8,573,923 B2
• Time in Patent Office: Days
• US Class Current: 415/115
• CPC Class Codes: F01D 5/186 Film cooling F01D5/187 takes precedence
• CPC Class Codes: F01D 9/041 using blades F01D5/148 takes precedence
• CPC Class Codes: F05D 2240/121 related to the leading edge of a stator vane
• CPC Class Codes: F05D 2240/122 related to the trailing edge of a stator vane
• CPC Class Codes: F05D 2240/303 related to the leading edge of a rotor blade
• CPC Class Codes: F05D 2240/304 related to the trailing edge of a rotor blade
• CPC Class Codes: F05D 2260/202 by film cooling
• CPC Class Codes: F05D 2260/22141 using fins or ribs

Abstract

A cooled aerofoil for a gas turbine engine has an aerofoil section with pressure and suction surfaces extending between inboard and outboard ends thereof. The aerofoil section includes first and second internal passages for carrying cooling air. The aerofoil section further includes a plurality of holes in the external surface of the aerofoil section which receive cooling air from the internal passages. The external holes are arranged such that cooling air exiting a first portion of the external holes participates in a cooling film extending from the leading edge of the aerofoil section over said pressure surface and cooling air exiting from a second portion of the external holes participates in a cooling film extending from the leading edge over said suction surface. The first portion of external holes receives cooling air from the first internal passage, and the second portion of external holes receives cooling air from the second internal passage. The first and second internal passages are supplied with cooling air from respective and separate passage entrances. Each entrance is located at either the inboard end or the outboard end of the aerofoil section.

Claims

1. A cooled aerofoil for a gas turbine engine, the aerofoil having an aerofoil section with pressure and suction surfaces extending between inboard and outboard ends thereof, wherein the aerofoil section includes:

first and second internal passages for carrying cooling air, and

a plurality of holes in the external surface of the aerofoil section which receive cooling air from the internal passages, the external holes being arranged such that cooling air exiting a first portion of the external holes participates in a cooling film extending from the leading edge of the aerofoil section over said pressure surface and cooling air exiting from a second portion of the external holes participates in a cooling film extending from the leading edge over said suction surface; and

wherein the first portion of external holes receives cooling air from the first internal passage, the second portion of external holes receives cooling air from the second internal passage, and the first and second internal passage are supplied with cooling air from respective and separate passage entrances, each entrance being located at either the inboard end or the outboard end of the aerofoil section.

2. A cooled aerofoil according to claim 1, wherein the aerofoil is a stator vane.

3. A cooled aerofoil according to claim 1, wherein the first and second internal passages are separated by a dividing wall which extends from the leading edge of the aerofoil.

4. A cooled aerofoil according to claim 1, wherein the first internal passage is supplied with cooling air from passage entrances located at both the inboard end and outboard end of the aerofoil section.

5. A cooled aerofoil according to claim 4, wherein the first internal passage contains a baffle to prevent cooling air supplied by the entrance located at one of the inboard and outboard ends from exiting the first internal passage at the entrance located at the other of the inboard and outboard ends.

6. A cooled aerofoil according to claim 1, wherein the second internal passage is a radial multi-pass passage which extends along a serpentine path from its entrance to the passage towards the leading edge of the aerofoil.

7. A cooled aerofoil according to claim 6, wherein the second internal passage makes at least two changes of direction between its entrance and the leading edge of the blade.

8. A cooled aerofoil according to claim 1, wherein the second internal passage has a fore section which extends towards the leading edge and an aft section, the cooling air entering the aft section before the fore section, the flow direction of the cooling air in the aft section being predominantly radial, and the flow direction of the cooling air in the fore section being predominantly in aft-fore direction.

9. A cooled aerofoil according to claim 1, wherein the passage entrances widen in the direction opposite to the direction of air supply.

10. A cooled aerofoil according to claim 1, wherein the second internal passage has flow-disrupting formations on its internal surface to increase heat transfer between the cooling air and the aerofoil section.

11. A cooled aerofoil according to claim 1, wherein the entrance for the second internal passage is located at the inboard end of the aerofoil section.

12. A cooled aerofoil according to claim 1, wherein the aerofoil section includes a further external hole or holes at its trailing edge, the second internal passage also supplying cooling air to the trailing edge external hole(s).

13. A cooled aerofoil according to claim 1 which is a casting, the internal passages being formed during the casting procedure.