Reduced take-off field length using variable nozzle

Patent metadata

Field	Value
Publication number	US-8935073-B2
Application number	US-37413109-A
Country	US
Kind code	B2
Filing date	Oct 12, 2006
Priority date	Oct 12, 2006
Publication date	Jan 13, 2015
Grant date	Jan 13, 2015

Abstract

A turbofan engine control system and method includes a core nacelle housing ( 12 ), a compressor and a turbine. A turbofan is arranged upstream from the core nacelle and is surrounded by a fan nacelle ( 34 ). A bypass flow path ( 39 ) is arranged downstream from the turbofan between the core and fan nacelles. The bypass flow path includes a nozzle exit area ( 40 ). A controller ( 50 ) detects at least one of a take-off condition and a landing condition. The controller changes effectively the nozzle exit area to achieve a thrust vector in response to the take-off and landing conditions.

First claim

The invention claimed is:

1. A turbofan engine control system comprising:
a core nacelle housing a compressor and a turbine;
a turbofan arranged upstream from the core nacelle and surrounded by a fan nacelle;
a bypass flow path downstream from the turbofan and arranged between the core and fan nacelles, the bypass flow path including a nozzle exit area;
a controller programmed to detect at least one of a take-off condition and a landing condition, the controller programmed to effectively alter the nozzle exit area to change a thrust vector in response to the at least one of the take-off and the landing conditions; and
wherein the core nacelle includes a low spool supporting the compressor and turbine, the low spool for rotationally driving the turbofan through an epicyclic gear train.

2. The turbofan engine control system according to claim 1 , wherein the landing condition includes initiation of a landing.

3. The turbofan engine control system according to claim 1 , wherein the core nacelle includes a high spool supporting a high pressure compressor and a high pressure turbine.

4. The turbofan engine control system according to claim 1 , comprising a flow control device including an actuator for changing the nozzle exit area physically in response to the at least one of the take-off and the landing conditions.

5. The turbofan engine control system according to claim 4 , wherein the flow control device includes flaps movable in response to the actuator to change the thrust vector.

6. The turbofan engine control system according to claim 5 , wherein a geometry of the nozzle exit area is changed in response to the at least one of the take-off and the landing conditions.

7. The turbofan engine control system according to claim 1 , wherein the take-off condition includes a maximum take-off throttle.

8. The turbofan engine control system according to claim 3 , wherein the gear train includes a gear reduction ratio greater than 2.5:1.

9. The turbofan engine control system according to claim 7 , wherein the controller is programmed to discontinue the thrust vector in response to an aircraft achieving a predetermined velocity.

10. The turbofan engine control system according to claim 3 , wherein the high and low spool and the turbofan provide a bypass ratio that is greater than 10:1.

11. The turbofan engine control system according to claim 3 , wherein the turbine of the low spool includes a pressure ratio that is greater than 5:1.

12. The turbofan engine control system according to claim 2 , wherein the controller is programmed to discontinue the thrust vector in response to a command manually by a pilot.

13. The turbofan engine control system according to claim 2 , wherein the initiation of the landing includes engagement of full flaps down.

14. A method of controlling a turbofan engine having a fan that is rotationally driven by an epicyclic gear train comprising the steps of:
a) determining at least one of a take-off condition and a landing condition;
b) effectively altering a turbofan bypass flow nozzle exit area in response to performing step a);
c) changing a thrust vector for the at least one of the take-off and the landing conditions; and
d) discontinuing the changed thrust vector in response to an aircraft achieving a predetermined velocity.

15. The method according to claim 14 , wherein step a) includes sensing a maximum take-off throttle.

16. The method according to claim 14 , wherein step a) includes initiating a landing.

17. The method according to claim 16 , wherein step a) includes engaging full flaps.

18. The method according to claim 16 , comprising step d) manually discontinuing the thrust vector.

19. The method according to claim 14 , wherein step b) includes changing the nozzle exit area physically in response to the at least one of the take-off and the landing conditions.

20. The method according to claim 14 , wherein steps a) through d) are performed by a controller programmed to detect at least one of a take-off condition and a landing condition and to effectively alter the nozzle exit area.

Assignees

• Hurwitz Wayne
• Jain Ashok K
• United Technologies Corp

Inventors

• Hurwitz Wayne
• Jain Ashok K

Classifications

• F02K1/06

  Varying effective area of jet pipe or nozzle (by using fluid jets to influence the jet flow F02K1/30) · CPC title

• F02K1/15

  Control or regulation · CPC title

• Y02T50/60

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

• F02K1/1207

  of one series of flaps hinged at their upstream ends on a fixed structure (F02K1/1215 - F02K1/1292 take precedence) · CPC title

• F02K1/002 Primary

  with means to modify the direction of thrust vector (F02K1/54 takes precedence; thrust vectoring of rockets F02K9/80) · CPC title