Twisted mixer with open center body

• US 20060112675A1
• Filed: 12/01/2004
• Published: 06/01/2006
• Est. Priority Date: 12/01/2004
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Anderson, Morris G., Ross, David F.
• Granted Patent: US 7,389,635 B2
• Time in Patent Office: Days
• US Class Current: 60/262
• 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: F02K 1/825 Infrared radiation suppressors
• CPC Class Codes: F05D 2250/314 the axes being inclined in relation to each other
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

An exhaust mixer assembly having a twisted mixer and an open centerbody is provided. The open centerbody is centrally disposed within the twisted mixer and helps to provide efficient cooling of exhaust air from gas turbine engines. A method for cooling exhaust air from a gas turbine engine using the exhaust mixer assembly of the invention is also provided.

Claims

1. An exhaust mixer assembly comprising:

a twisted mixer comprising a plurality of lobes and a plurality of troughs defined between the lobes, wherein the lobes and troughs are twisted about a centerline axis of the twisted mixer; and

an open centerbody disposed within the twisted mixer.

2. The exhaust mixer assembly of claim 1 wherein the lobes and troughs are twisted at an angle of no greater than 60°

with respect to the centerline axis.

3. The exhaust mixer assembly of claim 1 wherein the lobes and troughs are twisted at an angle of from about 10°

to about 30°

with respect to the centerline axis.

4. The exhaust mixer assembly of claim 1 wherein the open centerbody is centrally disposed within the twisted mixer.

5. The exhaust mixer assembly of claim 1 wherein the open centerbody has a cylindrical shape with an upstream end and an open downstream end and wherein a diameter of the upstream end is the same as a diameter of the downstream end.

6. The exhaust mixer assembly of claim 1 wherein the open centerbody has a cylindrical shape with an upstream end and an open downstream end and wherein a diameter of the upstream end is greater than a diameter of the downstream end.

7. The exhaust mixer assembly of claim 1 wherein the open centerbody has a cylindrical shape with an open or closed upstream end and an open downstream end and wherein a diameter of the upstream end is less than a diameter of the downstream end.

8. The exhaust mixer assembly of claim 1 further comprising an inner flow path for exhaust air, the inner flow path defined by the lobes and troughs of the twisted mixer and the open centerbody.

9. The exhaust mixer assembly of claim 8 further comprising an outer flow path for bypass air, wherein the outer flow path is defined by the lobes and troughs of the twisted mixer and an outer engine casing of a turbine engine.

10. The exhaust mixer assembly of claim 1 wherein the open centerbody further comprises an upstream end and at least one flange on the upstream end of the centerbody.

11. The exhaust mixer assembly of claim 1 wherein the open center body further comprises an upstream end and open notches for service lines on the upstream end of the centerbody.

12. The exhaust mixer assembly of claim 1 wherein the open centerbody and the twisted mixer are attached to a rear bearing support and aft frame of a turbine engine.

13. An exhaust mixer assembly comprising:

a twisted mixer comprising a plurality of lobes and a plurality of troughs defined between the lobes, wherein the lobes and troughs are twisted about a centerline axis of the twisted mixer, the twist about the centerline axis being no greater than 60° and

wherein the twisted mixer further comprises an outer surface and an inner surface;

an open centerbody centrally disposed within the twisted mixer wherein the open centerbody has a cylindrical shape and wherein the open centerbody further comprises an outer surface and an inner surface;

an inner flow path, the inner flow path defined by the outer surface of the open centerbody and the inner surface of the twisted mixer; and

an outer flow path, the outer flow path defined by the lobes and troughs of the twisted mixer and an outer engine casing.

14. The exhaust mixer assembly of claim 13 wherein the twist of the lobes and troughs of the twisted mixer is from about 10°

to about 30°

with respect to a leading edge of the lobes.

15. The exhaust mixer assembly of claim 13 wherein the twisted mixer comprises at least eight lobes and eight troughs.

16. The exhaust mixer assembly of claim 13 wherein the exhaust mixer assembly is part of an engine exhaust nozzle.

17. A turbine engine comprising:

a gear box;

air intake openings;

a casing covering turbo machinery of the turbine engine;

fuel lines;

a rear bearing support and aft frame; and

wherein an exhaust mixer assembly is attached to the engine at the rear bearing support and aft frame, the exhaust mixer assembly comprising a twisted mixer comprising a plurality of lobes and a plurality of troughs defined between the lobes, wherein the lobes and troughs are twisted about a centerline axis of the twisted mixer and an open centerbody centrally disposed within the twisted mixer wherein said centerbody has a cylindrical shape.

18. The turbine engine of claim 17 wherein the twisted mixer is attached to the rear bearing support and aft frame independently of the open centerbody.

19. The turbine engine of claim 18 wherein the twisted mixer is attached to the rear bearing support and aft frame by a ring clamp.

20. The turbine engine of claim 18 wherein the open centerbody further comprises an upstream end, wherein the upstream end comprises bolt hole flanges and wherein the open centerbody is connected to the rear bearing support and aft frame by bolting through the bolt hole flanges.

21. A gas turbine engine comprising:

an exhaust mixer assembly attached to the engine, the exhaust mixer assembly comprising a twisted mixer comprising a plurality of lobes and a plurality of troughs defined between the lobes, wherein the lobes and troughs are twisted about a centerline axis of the twisted mixer and an open centerbody centrally disposed within the twisted mixer wherein said centerbody has a cylindrical shape;

an outer engine casing covering the engine and exhaust mixer assembly;

an outer flow path for bypass air defined between the outer engine casing and the engine and twisted mixer; and

an inner flow path for exhaust air defined between the twisted mixer and the open centerbody.

22. The gas turbine engine of claim 21 wherein a twist of the lobes and troughs of the twisted mixer is from about 10°

to about 60°

with respect to the centerline axis.

23. The gas turbine engine of claim 21 wherein the twisted mixer is attached to the engine by a ring clamp.

24. The gas turbine engine of claim 21 wherein the twisted mixer is attached to the engine by a bolted flange.

25. The gas turbine engine of claim 21 wherein the open centerbody is attached to a rear bearing support and aft frame of the engine.

26. The gas turbine engine of claim 21 wherein the gas turbine engine is a turboshaft engine.

27. The gas turbine engine of claim 26 wherein the turboshaft engine is used in either a tank or helicopter.

28. The gas turbine engine of claim 21 wherein the gas turbine engine is a turbofan engine.

29. A method of cooling exhaust air from a gas turbine engine comprising the steps of:

streaming the exhaust air through an inner flow path of an exhaust mixer assembly, the inner flow path defined between a twisted mixer and an open centerbody of the exhaust mixer assembly and wherein the open centerbody is centrally disposed within the twisted mixer;

streaming bypass air through an outer flow path of the exhaust mixer assembly, the outer flow path defined between the twisted mixer and an outer engine casing; and

mixing the exhaust air and bypass air as they exit the exhaust mixer assembly.

30. The method of claim 29 wherein the exhaust air decreases at least about 500°

F. after mixing with the bypass air.

31. The method of claim 29 wherein the temperature of the exhaust air after mixing with the bypass air is about less than or equal to 500°

F.

32. The method of claim 29 wherein the method is used in a turboshaft gas turbine engine.

33. The method of claim 32 wherein the streaming exhaust air and bypass air have a pressure ratio sufficient to produce a desired thrust as they exit the engine.