초록 ▼

A turbofan engine control system for managing a low pressure turbine speed is provided. The turbofan engine control system includes a low spool having a low pressure turbine that are housed in a core nacelle. The low pressure turbine is adapted to rotate at a speed and includes a maximum design spee

A turbofan engine control system for managing a low pressure turbine speed is provided. The turbofan engine control system includes a low spool having a low pressure turbine that are housed in a core nacelle. The low pressure turbine is adapted to rotate at a speed and includes a maximum design speed. A turbofan is coupled to the low spool. A fan nacelle surrounds the turbofan and core nacelle and provides a bypass flow path. The bypass flow path includes a nozzle exit area. A controller is programmed to command a flow control device adapted to effectively decrease the nozzle exit area in response to a condition. Reducing the nozzle exit area, either physically or otherwise, maintains the speed below the maximum design speed.

대표청구항 ▼

1. A turbofan engine control system for managing a low pressure turbine speed comprising: a low spool including a low pressure turbine housed in a core nacelle, the low pressure turbine rotatable at a speed and having a maximum design speed;a turbofan coupled to the low spool;a fan nacelle surroundi

1. A turbofan engine control system for managing a low pressure turbine speed comprising: a low spool including a low pressure turbine housed in a core nacelle, the low pressure turbine rotatable at a speed and having a maximum design speed;a turbofan coupled to the low spool;a fan nacelle surrounding the turbofan and core nacelle and providing a bypass flow path having a nozzle exit area;a controller programmed to command a flow control device and effectively decrease the nozzle exit area in response to a condition that would result in at least an undesired speed of the low pressure turbine for maintaining the speed below the maximum design speed; anda gear train interconnecting the low spool and the turbofan for reducing a turbofan speed relative to the speed. 2. The turbofan engine control system according to claim 1, comprising a high spool rotatable relative to the low spool, the high spool supporting a high pressure compressor and high pressure turbine. 3. The turbofan engine control system according to claim 1, wherein the flow control device includes an actuator for manipulating a flap in response to the command to physically reduce the nozzle exit area. 4. The turbofan engine control system according to claim 1, comprising a speed sensor in communication with the controller for detecting the speed, the condition relating to the speed. 5. The turbofan engine control system according to claim 1, comprising an altitude sensor in communication with the controller for detecting an aircraft altitude, the condition relating to the aircraft altitude. 6. The turbofan engine control system according to claim 1, comprising a throttle position sensor in communication with the controller for detecting an engine throttle position, the condition relating to the engine throttle position. 7. A method of managing a low pressure turbine speed in a turbofan engine comprising the steps of: detecting a condition affecting a speed of a low pressure turbine mounted on a low spool;determining, by a turbofan engine control system, if the condition would cause the speed to reach an undesired speed relative to a maximum design speed for the low pressure turbine;effectively reducing a nozzle exit area in response to determining the condition would result in at least the undesired speed;wherein the turbofan engine control system comprises: the low spool, the low spool including the low pressure turbine housed in a core nacelle, the low pressure turbine rotatable at a speed and having the maximum design speed;a turbofan coupled to the low spool;a fan nacelle surrounding the turbofan and core nacelle and providing a bypass flow path having the nozzle exit area;a controller programmed to command a flow control device and effectively decrease the nozzle exit area in response to a condition that would result in at least the undesired speed of the low pressure turbine for maintaining the speed below the maximum design speed; anda gear train interconnecting the low spool and the turbofan for reducing a turbofan speed relative to the speed. 8. The method according to claim 7, comprising the step of detecting an aircraft altitude, the condition including the altitude. 9. The method according to claim 7, comprising the step of detecting a throttle position, the condition including the throttle position. 10. The method according to claim 7, comprising the step of detecting the speed. 11. The method according to claim 7, wherein the step of effectively reducing the nozzle exit area include reducing a physical size of the nozzle exit area. 12. The method according to claim 7, comprising the step of generating a backpressure on a turbofan after performing the step of effectively reducing the nozzle exit area. 13. The method according to claim 12, wherein the step of generating backpressure counteracts an increase the speed toward the maximum design speed.