INTEGRATED TURBINE EXHAUST STRUTS AND MIXER OF TURBOFAN ENGINE

• US 20150337761A1
• Filed: 10/23/2014
• Published: 11/26/2015
• Est. Priority Date: 05/26/2014
• Status: Active Grant

• Current Assignee: Pratt & Whitney Canada Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Pratt & Whitney Canada Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: CUNNINGHAM, Mark Huzzard, MARINI, Remo
• Granted Patent: US 9,759,159 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F01D 25/30 Exhaust heads, chambers, or the like
• CPC Class Codes: F01D 9/041 using blades F01D5/148 takes precedence
• CPC Class Codes: F02K 1/386 mixing devices in the jet pipe, e.g. for mixing primary and secondary flow
• CPC Class Codes: F02K 1/48 Corrugated nozzles
• CPC Class Codes: F05D 2240/12 Fluid guiding means, e.g. vanes
• CPC Class Codes: F05D 2250/61 corrugated

Abstract

A turbine exhaust case (TEC) of a turbofan aeroengine includes a mixer in an annular wavy configuration having alternate crests and valleys, and a plurality of radial deswirling struts interconnecting an annular hub positioned within the mixer and selected valleys of the mixer. A plurality of secondary trailing edge struts smaller than the deswirling struts in average chord dimensions interconnect the annular hub and other selected valleys free of connection with the deswirling struts.

Claims

1. A turbine exhaust case (TEC) of a turbofan aeroengine comprising an annular hub and an annular shroud with a mixer attached to a downstream end of the shroud for mixing exhaust gases with a bypass air stream, the mixer including a plurality of axially extending lobes of the mixer arranged in alternating crests and valleys extending divergently in a downstream direction, the mixer surrounding the hub to form an annular exhaust gas duct between the mixer and the hub, a plurality of deswirling struts extending generally radially across the annular exhaust gas duct axially within the mixer to connect the mixer and the hub, the deswirling struts connected to the mixer via a selected first group of the valleys of the mixer, a plurality of secondary struts each having an average chord length shorter than an average chord length of the respective deswirling struts, the secondary struts generally radially extending across the annular gas duct to connect the mixer and the hub, the secondary struts connected to the mixer via a selected second group of the valleys distinct from the first group of valleys, the secondary struts connected to said second group of the valleys immediately upstream of a trailing edge of said valleys.

2. The TEC as defined in claim 1 wherein the deswirling struts each comprise a cambered profile, the cambered profile being cambered in a direction of an incoming swirling flow of the exhaust gases.

3. The TEC as defined in claim 1 wherein the deswirling struts are axially spaced away from the trailing edges of the respective valleys of the selected first group.

4. The TEC as defined in claim 1 wherein the deswirling struts are axially located in an axial upstream half of the mixer.

5. The TEC as defined in claim 1 wherein the secondary struts each comprise an airfoil profile.

6. The TEC as defined in claim 1 wherein the secondary struts each comprise a flat plate.

7. The TEC as defined in claim 1 wherein a total number of the deswirling struts and the secondary struts is less than a total number of the valleys of the mixer.

17. The turbofan aeroengine as defined in claim 1 wherein the secondary struts each comprise a flat plate.

8. A turbofan aeroengine comprises a turbine exhaust case (TEC) positioned downstream of a turbine section of the turbofan aeroengine for directing a flow of gases exhausted from the turbine section, the TEC including an inner annular hub surrounded by an annular outer wall, a downstream end section of the annular outer wall being in a circumferential wavy configuration to form a plurality of axially extending lobes defining alternating crests and valleys extending divergently to a downstream end of the TEC, the crests defining internal axial and radially-outward passages for directing gases exiting from the turbine section to pass through the TEC, and the valleys defining external axial and radially-inward passages for directing a bypass air stream to pass along an external surface of the TEC, resulting in mixing of the gases with the bypass air stream, a number of circumferentially spaced deswirling struts each having a cambered profile and being located within an axial length of the wavy configuration, the deswirling struts radially interconnecting the annular hub and a first selected group of the valleys;

a number of secondary struts each having an average chord length shorter than the average chord length of the respective deswirling struts, the secondary struts radially interconnecting the annular hub and a selected second group of the valleys free of connection of the deswirling struts and being located immediately upstream of a trailing edge of the selected second group of the valleys.

9. The turbofan aeroengine as defined in claim 8 wherein the deswirling struts each comprise a leading edge and a trailing edge, the leading edges of the deswirling struts being axially spaced away from a start point of the divergently extending crests and valleys, and the trailing edges of the deswirling struts being axially spaced away from the trailing edges of the respective valleys of the selected first group.

10. The turbofan aeroengine as defined in claim 8 wherein the deswirling struts and the secondary struts are circumferentially distributed such that each of the deswirling struts is positioned between adjacent two of the secondary struts.

11. The turbofan aeroengine as defined in claim 8 wherein the deswirling struts and the secondary struts are circumferentially distributed such that each of the secondary struts is positioned between adjacent two of the deswirling struts.

12. The turbofan aeroengine as defined in claim 8 wherein the deswirling struts and the secondary struts are circumferentially distributed in an alternating pattern of every one or more of the deswirling struts and every one or more of the secondary struts.

13. The turbofan aeroengine as defined in claim 8 wherein a total number of the deswirling struts and the secondary struts is equal to the number of the valleys.

14. The turbofan aeroengine as defined in claim 8 wherein a total number of the deswirling struts and the secondary struts is less than the number of the valleys.

15. The turbofan aeroengine as defined in claim 8 wherein the downstream end of the TEC comprises a jagged trailing edge.

16. The turbofan aeroengine as defined in claim 8 wherein the secondary struts each comprise an airfoil profile.