TURBINE BLADE COOLING

• US 20180073370A1
• Filed: 08/22/2017
• Published: 03/15/2018
• Est. Priority Date: 09/14/2016
• Status: Abandoned Application

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: MOTTRAM, Martin, HUNT, David J., LI, Haidong, SHAHPAR, Shahrokh, CALONI, Stefano
• Application Number:
  US15/683,339
• Publication Number:
  US 20180073370A1
• Time in Patent Office: Days
• CPC Class Codes: F01D 5/141 Shape, i.e. outer, aerodynamic form F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147
• CPC Class Codes: F01D 5/186 Film cooling F01D5/187 takes precedence
• CPC Class Codes: F01D 5/20 Specially-shaped blade tips to seal space between tips and stator F01D5/225 takes precedence
• CPC Class Codes: F05D 2240/304 related to the trailing edge of a rotor blade
• CPC Class Codes: F05D 2240/307 related to the tip of a rotor blade
• CPC Class Codes: F05D 2250/314 the axes being inclined in relation to each other
• CPC Class Codes: F05D 2250/52 Outlet
• CPC Class Codes: F05D 2260/202 by film cooling

Abstract

A blade includes a root and an elongate portion extending to a tip, the elongate portion having an aerofoil-shaped cross-section. The aerofoil has leading and trailing edges, and suction and pressure sides. The tip includes a squealer defining a gutter at the tip, the squealer extending from the trailing edge along the entirety of a first of the suction and pressure sides, around the leading edge and partly along a second of the suction and pressure sides leaving a gap between the trailing edge and an end of the wall. A main trailing edge cooling channel extends within the elongate portion in a direction from root to tip adjacent the trailing edge and exits into the gutter. The main trailing edge cooling channel includes a bend just downstream of the exit, the exit displaced from a camber line of the blade elongated portion towards the second side.

Claims

1. A blade comprising a root portion and an elongate portion extending from the root portion to a tip, the elongate portion having an aerofoil-shaped cross section having a leading edge, a trailing edge, a suction side and a pressure side, the tip including a squealer defining a gutter at the tip wherein the squealer comprises a wall extending from the trailing edge along the entirety of a first of the suction side and pressure side, around the leading edge and partly along a second of the suction side and pressure side leaving a gap between the trailing edge and an end of the wall on the second side, a main trailing edge cooling channel extending within the elongate portion in a direction from root to tip adjacent the trailing edge and exiting into the gutter, wherein the main trailing edge cooling channel includes a bend just upstream of the exit such that the exit is displaced from a camber line of the blade elongated portion towards the second side.

2. A blade as claimed in claim 1 wherein the first side is the pressure side and the main trailing edge cooling channel bends towards the suction side.

3. A blade as claimed in claim 1 wherein the first side is the suction side and the main trailing edge cooling channel bends towards the pressure side.

4. A blade as claimed in claim 1 wherein the gutter is shallower adjacent the leading edge than it is at the trailing edge.

5. A blade as claimed in claim 1 wherein the gutter in the region of the trailing edge is inclined from the first side towards the second side whereby to maintain a surface which is substantially orthogonal to the walls of the main trailing edge cooling channel where they meet the gutter.

6. A blade as claimed in claim 1 further comprising a gallery channel integrally cast into the blade using an adapted core which defines both the main trailing edge cooling channel and has an extension defining the gallery channel.

7. A blade as claimed in claim 5 wherein the gallery channel is provided in a shape which minimises flow restriction in the gallery channel.

8. A blade as claimed claim 5 wherein the gallery channel is spout shaped having a larger diameter at an open end where it intersects the main trailing edge cooling channel and a smaller diameter at a closed end which sits just behind an apogee of the trailing edge.

9. A blade as claimed in claim 5 wherein a tip facing surface of the gallery channel is profiled to complement and extend in parallel with the surface of the gutter in the trailing edge region.

10. A blade as claimed in claim 5 wherein the gallery channel is shaped to follow variations in the depth of the gutter.

11. A blade as claimed in claim 5 further comprising an array of film cooling channels extending from the gallery channel and through the squealer wall.

12. A blade as claimed in claim 1 wherein the depth of the squealer wall varies from a first depth at the leading edge to a second and greater depth at the trailing edge.

13. A blade as claimed in claim 1 wherein the width of the squealer wall is variable.

14. A blade as claimed in claim 13 wherein the width of the squealer wall reduces from a maximum width at a first end of the squealer wall to a minimum width at a second end of the squealer wall.

15. A blade as claimed in claim 1 wherein the squealer wall includes a locally extended portion adjacent the trailing edge on the first side, the extended portion extending in a widthwise direction with respect to the squealer wall and away from the gutter.

16. A blade as claimed in claim 1 configured for use in a gas turbine engine.