# US 9,752,774 B2 · Fuel nozzle

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- Number: US 9,752,774 B2
- Document ID: US9752774B2
- Status: Granted
- Kind: B2
- Application number: 14/505,787
- Filed: 2014-10-03
- Published: 2016-04-07
- Granted: 2017-09-05
- Earliest claimed: 2014-10-03
- Assignees: Pratt & Whitney Canada Corp.
- Applicants: Pratt & Whitney Canada Corp.
- Inventors: Yen-Wen Wang; Nigel Davenport
- Web page: https://patentgrep.com/patent/US9752774B2

## CPC

- F23D 11/383: {with swirl means}
- F23D 11/102: {in an internal mixing chamber}
- F23D 11/103: {with means creating a swirl inside the mixing chamber}
- F23D 11/107: {at least one of both being subjected to a swirling motion}
- F23R 3/12: inducing a vortex
- F23R 3/286: {having fuel-air premixing devices (F23R3/30 takes precedence)}
- F23D 2900/14021: Premixing burners with swirling or vortices creating means for fuel or air
- F23D: BURNERS
- F23R: GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY, e.g. GAS-TURBINE COMBUSTION CHAMBERS (fluidised bed combustion apparatus specially adapted for operation at superatmospheric pressures F23C10/16)

## Abstract

A fuel nozzle for a combustor of a gas turbine engine includes a body defining an axial direction and a radial direction, an air passageway defined axially in the body, and a fuel passageway defined axially in the body radially outwardly from the air passageway. The air passageway has a swirl-inducing relief defined at an exit lip of an outer wall of the air passageway. A gas turbine engine and a method of inducing swirl in an air passageway of a fuel nozzle of a gas turbine engine are also presented.

## Claims

### Claim 1

A fuel nozzle for a combustor of a gas turbine engine, the fuel nozzle comprising:
a body defining an axial direction and a radial direction, the body defining an air passageway and a fuel passageway each extending axially through the fuel nozzle, the air passageway being centrally disposed within the body and the fuel passageway being annular and disposed radially outward of the air passageway, the body accommodated within an annular duct having a converging section at a downstream end thereof and terminating at an exit lip of the fuel nozzle, a mixing zone defined within the converging section of the annular duct downstream of the body; and
the air passageway having a swirl-inducing relief defined at an exit of an outer wall of the air passageway upstream of the mixing zone, the swirl-inducing relief including a plurality of helicoidal grooves formed into an inner surface of the outer wall of the air passageway.

### Claim 2 (depends on 1)

The fuel nozzle of claim 1, wherein the swirl-inducing relief extends on the outer wall up to a downstream end of the air passageway.

### Claim 3 (depends on 1)

The fuel nozzle of claim 1, wherein the plurality of grooves are circular in cross-section.

### Claim 4 (depends on 1)

The fuel nozzle of claim 1, wherein the plurality of grooves have a sawtooth cross-sectional shape.

### Claim 5 (depends on 1)

The fuel nozzle of claim 1, wherein a downstream end of the air passageway is axially upstream relative to a downstream end of the fuel passageway.

### Claim 6

A gas turbine engine comprising:
a combustor; and
a plurality of fuel nozzles disposed inside the combustor, each of the fuel nozzles including:
a body defining an axial direction and a radial direction, the body accommodated within an annular duct having a converging section at a downstream end thereof and terminating at an exit lip of the fuel nozzle, a mixing zone defined within the converging section of the annular duct downstream of the body;
an air passageway extending axially through the body at a center thereof; and
a fuel passageway extending axially through the body radially outwardly from the air passageway, the air passageway having a swirl-inducing relief at an exit lip of an outer wall of the air passageway, the swirl-inducing relief including a plurality of helicoidal grooves formed into an inner surface of the outer wall of the air passageway to induce swirl to an air flow exiting the air passageway and entering the mixing zone.

### Claim 7 (depends on 6)

The gas turbine engine of claim 6, wherein the swirl-inducing relief extends on the outer wall up to a downstream end of the air passageway.

### Claim 8 (depends on 6)

The gas turbine engine of claim 6, wherein the plurality of grooves are circular in cross-section.

### Claim 9 (depends on 6)

The gas turbine engine of claim 6, wherein the plurality of grooves have a sawtooth cross-sectional shape.

### Claim 10 (depends on 6)

The gas turbine engine of claim 6, wherein a downstream end of the air passageway is axially upstream relative to a downstream end of the fuel passageway.