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US 11,401,889 B2Granted
Gas turbine engine variable area fan nozzle control
AssigneeRaytheon Technologies Corporation
InventorsGeoffrey T. Blackwell, William J. McVey, William G. Tempelman
Life of this patent
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Abstract
A method of managing a gas turbine engine includes the steps of detecting an airspeed and detecting a fan speed. A parameter relationship is referenced related to a desired variable area fan nozzle position based upon at least airspeed and fan speed. The detected airspeed and detected fan speed is compared to the parameter relationship to determine a target variable area fan nozzle position. An actual variable area fan nozzle position is adjusted in response to the determination of the target area fan nozzle position and at least one threshold.
Claims27
A turbofan gas turbine engine comprising:
- a fan section including a fan having a fan blade, and a fan pressure ratio of less than 1.45 across the fan blade alone at cruise at 0.8 Mach and 35,000 feet;
- a compressor section including a first compressor and a second compressor;
- a turbine section including a first turbine and a fan drive turbine, wherein the first turbine drives the second compressor;
- a fan nacelle surrounding the fan and a core nacelle to provide a bypass flow path, and including a variable area fan nozzle coupled to one or more actuators, wherein the variable area fan nozzle is movable between a first position and a second position in response to the one or more actuators;
- and
- a controller that references a parameter relationship relating to a desired variable area fan nozzle position based upon at least airspeed and fan speed, compares a detected airspeed and a detected fan speed to the parameter relationship to determine a target variable area fan nozzle position, the parameter relationship including first and second thresholds respectively corresponding to upper and lower fan speed limits that provide a schedule of curves of the fan speed in relation to a fan aerodynamic design speed, wherein the upper fan speed limit and the lower fan speed limit are less than the fan aerodynamic design speed, selects the target variable area fan nozzle position according to the schedule of curves, and provides a command to the one or more actuators to adjust the variable area fan nozzle from the first position to the second position corresponding to the target variable fan nozzle position.
3 more elements
A method of managing a turbofan gas turbine engine comprising the steps of:
- providing a fan section including a fan having a fan blade arranged in a fan nacelle and a fan pressure ratio of less than 1.45 across the fan blade alone at cruise at 0.8 Mach and 35,000 feet, the fan nacelle surrounding the fan and a core nacelle to provide a bypass flow path, and the fan nacelle including a variable area fan nozzle coupled to one or more actuators, wherein the variable area fan nozzle is moveable relative to an engine longitudinal axis in response to the one or more actuators;
- rotating a first spool about the engine longitudinal axis to rotate the fan, the first spool including a first compressor and a fan drive turbine;
- rotating a second spool about the engine longitudinal axis, the second spool including a second compressor and a first turbine;
- detecting an airspeed;
- detecting a fan speed;
- referencing a parameter relationship related to a desired variable area fan nozzle position based upon at least airspeed and fan speed, the parameter relationship including first and second thresholds respectively corresponding to upper and lower fan speed limits that provide a schedule of curves of the fan speed in relation to a fan aerodynamic design speed, wherein the upper fan speed limit and the lower fan speed limit are less than the fan aerodynamic design speed;
- comparing the detected airspeed and the detected fan speed to the parameter relationship to determine a target variable area fan nozzle position according to the schedule of curves;
- and
- adjusting an actual variable area fan nozzle position of the variable area fan nozzle to the target variable area fan nozzle position to adjust a bypass flow in the bypass flow path and to adjust an exit area of the fan nacelle.
6 more elements
Dependencies are inferred from the claim text.