Managing low pressure turbine maximum speed in a turbofan engine
AssigneeUnited Technologies Corporation
InventorWilliam J. McVey
Life of this patent
Estimating the term…
Abstract
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.
Claims13
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;
- and
- a gear train interconnecting the low spool and the turbofan for reducing a turbofan speed relative to the speed.
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;
- and
- a gear train interconnecting the low spool and the turbofan for reducing a turbofan speed relative to the speed.
Dependencies are inferred from the claim text.