NOZZLE ARRANGEMENT FOR A GAS TURBINE ENGINE

• US 20160010590A1
• Filed: 07/01/2015
• Published: 01/14/2016
• Est. Priority Date: 07/09/2014
• Status: Active Grant

• Current Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce PLC (Rolls-Royce Holdings Plc)
• Inventors: ROLT, Andrew Martin
• Granted Patent: US 10,371,094 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F01D 17/143 the shiftable member being a wall, or part thereof of a radial diffuser
• CPC Class Codes: F02C 3/04 having a turbine driving a compressor power transmission arrangements F02C7/36; control of working fluid flow F02C9/16
• CPC Class Codes: F02K 1/08 by axially moving or transversely deforming an internal member, e.g. the exhaust cone
• CPC Class Codes: F02K 1/09 by axially moving an external member, e.g. a shroud F02K1/12 takes precedence
• CPC Class Codes: F02K 1/15 Control or regulation
• CPC Class Codes: F02K 1/48 Corrugated nozzles
• CPC Class Codes: F02K 3/025 the by-pass flow being at least partly used to create an independent thrust component
• CPC Class Codes: F02K 3/06 with front fan
• CPC Class Codes: F02K 3/075 controlling flow ratio between flows
• CPC Class Codes: F05D 2220/323 for aircraft propulsion, e.g. jet engines
• CPC Class Codes: F05D 2250/311 the axes being in line
• CPC Class Codes: F05D 2250/41 with one degree of freedom
• CPC Class Codes: F05D 2260/20 Heat transfer, e.g. cooling
• CPC Class Codes: F05D 2260/213 by the provision of a heat exchanger within the cooling circuit
• CPC Class Codes: F05D 2260/57 using servos, independent actuators, etc.
• CPC Class Codes: F05D 2260/96 Preventing, counteracting or reducing vibration or noise
• CPC Class Codes: F05D 2270/101 Compressor surge or stall
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft

Abstract

A gas turbine engine comprising: a bypass duct having a bypass nozzle; an engine core having a core nozzle; and, a mixer duct defined by a mixer fairing and having a mixer nozzle, wherein the mixer duct is arranged to receive an airflow from the bypass duct through a mixer duct inlet and an airflow from the engine core, when in use, and the geometry of the mixer duct is selectively adjustable by moving the mixer fairing relative to the bypass duct and engine core in use.

Claims

1. A gas turbine engine comprising:

a bypass duct having a bypass nozzle;

an engine core having a core nozzle; and

,

a mixer duct having a mixer duct inlet and a mixer nozzle defined by a mixer fairing which is movably mounted to the engine and,

wherein the mixer duct is arranged to receive an airflow from the bypass duct through the mixer duct inlet and an airflow from the engine core, when in use, and the geometry of the mixer duct is selectively adjustable by moving the mixer fairing relative to the bypass duct and engine core in use,

wherein the mixer fairing is movable between a first position and second position which simultaneously alters one or more of;

an output flow area of the bypass nozzle, an output flow area of the mixer nozzle, and, a throat area of the mixer duct inlet, such that the respective in use airflows are altered.

2. A gas turbine engine as claimed in claim 1, wherein moving the mixer fairing between the first and second position alters all of:

the output flow area of the bypass nozzle, the output flow area of the mixer nozzle, and, the throat area of the mixer duct inlet.

3. A gas turbine engine as claimed in claim 1, wherein a portion of radially outer wall of the mixer fairing downstream of the leading edge is substantially parallel to the axis of movement such that moving the mixer fairing between a first and second position alters the output flow area of the mixer nozzle and moving the mixer fairing between a second and third position alters the output flow area of the bypass nozzle and mixer nozzle.

4. A gas turbine engine as claimed in claim 3, wherein moving the mixer fairing between the second and third positions additionally alters the mixer duct inlet flow area.

5. A gas turbine engine as claimed in claim 1, wherein the mixer fairing is axially translatable relative to the principal axis of the gas turbine engine so as to alter the geometry of the mixer duct.

6. A gas turbine engine as claimed in claim 1 further comprising a tail cone, wherein the position of the tail cone is selectively adjustable relative to the engine core.

7. A gas turbine engine as claimed in claim 1 wherein the engine core nozzle exits directly into the mixer duct.

8. A gas turbine engine as claimed in claim 1 wherein the leading edge of the mixer fairing is at least partially located within the bypass duct in the first and second positions.

9. A gas turbine engine as claimed in claim 1 wherein either or both of the mixer fairing and the trailing edge of the core fairing includes lobes to aid mixing of the engine core airflow and bypass airflow.

10. A gas turbine engine as claimed in claim 6 wherein the mixer fairing and tail cone are configured to move simultaneously.

11. A gas turbine engine as claimed in claim 10 wherein the mixer fairing is mounted to the gas turbine engine via the tail cone.

12. A gas turbine engine as claimed in claim 1 wherein the mixer fairing is mounted on a pylon which is attached to the wing or airframe of an aircraft.

13. A gas turbine engine as claimed in claim 6 wherein a portion of the mixer duct is defined by the tail cone and the mixer duct fairing which are arranged to have a chute therebetween, the minimum flow area of which is adjustable with the movement of the mixer fairing.

14. A gas turbine engine as claimed in claim 1, wherein the mixer fairing includes a heat exchanger.

15. A gas turbine engine as claimed in claim 1, further comprising a thrust reverser having at least one door which is operable to substantially block the bypass duct in a thrust reversing operation, wherein the door includes at least one aperture in an upstream flow path relative to the leading edge of the mixer fairing such that a leading edge of the mixer fairing is provided with a cooling air flow when the thrust reverser door is deployed.

16. A gas turbine engine as claimed in claim 1, further comprising a thrust measurement system and at least one sensor operably connected to the thrust measurement system, wherein the sensor is configured to provide the system with a signal which is representative of the position of the mixer fairing and the thrust measurement system determines the engine thrust using the position of the mixer fairing.

17. A gas turbine engine as claimed in claim 16, further comprising a tail cone and a tail cone position sensor, and the thrust measurement system determines the engine thrust using the position of either or both the mixer fairing and tail cone.

18. A gas turbine engine as claimed in claim 1, an engine control system and at least one sensor operably connected to the engine control system, wherein the sensor is configured to provide the system with a signal which is representative of the position of the mixer fairing, and the engine control system is configured to adjust the mixer duct in use.

19. A gas turbine engine as claimed in claim 18, wherein the engine control system reduces the output flow area of the bypass nozzle and the output flow area of the mixer nozzle with an increase in fan speed a main propulsive fan of the gas turbine engine.