Segmented multi-lobe mixer

Patent metadata

Field	Value
Publication number	US-2016376928-A1
Application number	US-201514750094-A
Country	US
Kind code	A1
Filing date	Jun 25, 2015
Priority date	Jun 25, 2015
Publication date	Dec 29, 2016
Grant date	—

Abstract

A multi-lobe exhaust mixer has an annular body composed of a plurality of circumferentially adjacent lobe segments. The lobe segments may be made of a ceramic matrix composite material to reduce the weight of the mixer and ensure proper behavior when exposed to high thermal gradients. Each lobe segment may have partial lobes at circumferentially opposed ends thereof and at least one complete lobe therebetween. The partial lobes of the circumferentially adjacent lobe segments combining to conjointly form complete lobes at the junction between the circumferentially adjacent lobe segments. The partial lobes may be nested into each other to dampen vibrations.

First claim

1 . A multi-lobe exhaust mixer for a gas turbine engine, the multi-lobe exhaust mixer comprising: an annular body having an array of circumferentially distributed alternating inner and outer lobes, the inner lobes including troughs forming an inner radial portion thereof and the outer lobes including crests forming an outer radial portion thereof, the annular body being segmented into a plurality of individual lobe segments, and wherein the individual lobe segments overlap at the crests or the troughs.

2 . The multi-lobe exhaust mixer as defined in claim 1 , wherein each of the individual lobe segments has partial lobes at circumferentially opposed ends and at least one complete lobe therebetween, and wherein the partial lobes of circumferentially adjacent lobe segments are nested into each other.

3 . The multi-lobe exhaust mixer defined in claim 2 , wherein the inner or outer lobe formed at a junction of circumferentially adjacent first and second individual lobe segments has a first sidewall which is part of the first lobe segment and a second sidewall which is part of the second lobe segment.

4 . The multi-lobe exhaust mixer defined in claim 2 , wherein the individual lobe segments comprise an intermediate lobe segment disposed between first and second adjacent lobe segments, and wherein the partial lobes of the intermediate lobe segment respectively extend radially outwardly over and radially inwardly under the first and second adjacent lobe segments.

5 . The multi-lobe exhaust mixer defined in claim 1 , wherein the individual lobe segments are made of a ceramic matrix composite (CMC) material.

6 . The multi-lobe exhaust mixer defined in claim 1 , wherein the individual lobe segments are mounted at an upstream end thereof to a support ring.

7 . The multi-lobe exhaust mixer defined in claim 6 , wherein the individual lobe segments are spring loaded on the support ring.

8 . The multi-lobe exhaust mixer defined in claim 7 , wherein the support ring has a sheet metal spring loaded flange upon which the individual lobe segments rest, and wherein a separate flange detachably mounted to support ring axially retain and clamp the individual lobe segments on the support ring.

9 . The multi-lobe exhaust mixer defined in claim 8 , wherein a damping material is wrapped around the upstream end of the individual lobe segments on the support ring, and wherein the separate flange extends over the damping material.

10 . The multi-lobe exhaust mixer defined in claim 9 , wherein the damping material is a ceramic fiber tape.

11 . A multi-lobe exhaust mixer for a gas turbine engine, the multi-lobe exhaust mixer comprising: an annular body composed of a plurality of circumferentially adjacent lobe segments, each lobe segment having partial lobes at circumferentially opposed ends thereof and at least one complete lobe therebetween, the partial lobes of the circumferentially adjacent lobe segments combining to conjointly form complete lobes at the junction between the circumferentially adjacent lobe segments.

12 . The multi-lobe exhaust mixer defined in claim 11 , wherein the partial lobes of the circumferentially adjacent lobe segments overlap each other.

13 . The multi-lobe exhaust mixer defined in claim 12 , wherein the partial lobes overlap at a crest or a trough.

14 . The multi-lobe exhaust mixer defined in claim 13 , wherein the partial lobes of circumferentially adjacent lobe segments nest within each other.

15 . A multi-lobe exhaust mixer for a gas turbine engine of the type having an annular core flow passage for channelling a high temperature core flow along an axis of the engine, and a bypass passage extending concentrically about the core flow passage for axially channelling bypass air; the multi-lobe exhaust mixer comprising: an annular body having an array of circumferentially distributed alternating inner and outer lobes, the outer lobes configured to protrude radially outwardly into the bypass passage and the inner lobes configured to protrude radially inwardly into the core flow passage, the annular body being composed of a plurality of individual lobe segments which alternately radially outwardly and radially inwardly overlap each other around the annular body.

16 . The multi-lobe exhaust mixer defined in claim 15 , wherein the inner lobes include troughs forming an inner radial portion thereof and the outer lobes include crests forming an outer radial portion thereof, and wherein circumferentially adjacent lobe segments overlap each other at the crests or the troughs.

17 . The multi-lobe exhaust mixer defined in claim 16 , wherein each of the individual lobe segments has partial lobes at circumferentially opposed ends and at least one complete lobe therebetween, and wherein the partial lobes of circumferentially adjacent lobe segments are nested into each other.

18 . The multi-lobe exhaust mixer defined in claim 15 , wherein the individual lobe segments comprise an intermediate lobe segment disposed between first and second adjacent lobe segments, and wherein the partial lobes of the intermediate lobe segment respectively extend radially outwardly over and radially inwardly under the first and second adjacent lobe segments.

19 . The multi-lobe exhaust mixer defined in claim 15 , wherein the individual lobe segments are clamped at an upstream end thereof to a support ring.

20 . A lobe segment adapted to be assembled to similar circumferentially adjacent lobe segments to form a multi-lobe exhaust mixer of a gas turbine engine, the lobe segment having partial lobes at circumferentially opposed ends thereof and at least one complete lobe therebetween, the partial lobes of the lobe segment being nestable into corresponding partial lobes of circumferentially adjacent lobe segments.

Assignees

• Pratt & Whitney Canada

Inventors

• Lefebvre Guy
• Paquet Rene

Classifications

• Y02T50/60

  Efficient propulsion technologies, e.g. for aircraft · CPC title

• F05D2260/30

  Retaining components in desired mutual position · CPC title

• F05D2300/6033

  Ceramic matrix composites [CMC] · CPC title

• F01D25/005

  Selecting particular materials · CPC title

• F05D2260/96

  Preventing, counteracting or reducing vibration or noise · CPC title