A method to reduce aerodynamic drag of a engine exhaust/engine nozzle includes collecting data that is indicative of an instant flight condition, entering the data into a decision algorithm that, based on the data, outputs at least first and second drag control parameters corresponding, respectively, to an angle of one or more variable area turbines of a turbine engine and a position of a variable area exhaust nozzle of the turbine engine, and adjusting the angle of the one or more variable area turbines and the position of the variable area exhaust nozzle according to, respectively, the first and second drag control parameters to reduce aerodynamic drag of an engine exhaust/engine nozzle of the turbine engine.

A method to reduce aerodynamic drag of a engine exhaust/engine nozzle includes collecting data that is indicative of an instant flight condition, entering the data into a decision algorithm that, based on the data, outputs at least first and second drag control parameters corresponding, respectively, to an angle of one or more variable area turbines of a turbine engine and a position of a variable area exhaust nozzle of the turbine engine, and adjusting the angle of the one or more variable area turbines and the position of the variable area exhaust nozzle according to, respectively, the first and second drag control parameters to reduce aerodynamic drag of an engine exhaust/engine nozzle of the turbine engine.

The present disclosure provides a device for controlling a variable section ejection nozzle of a turbojet engine nacelle of an aircraft. The device includes a calculator adapted to determine a position setpoint of the nozzle and a management system of the servo-control of the position of the variable nozzle depending on the flow rate of the fuel supplying the turbojet engine. The management system includes at least one instantaneous flow rate sensor of the fuel and a management unit which is designed to compare the flow rate measured by the flow rate sensor with a theoretical fuel flow rate depending on the parameters of the flight of the aircraft, to determine a correction value of the position of the nozzle depending on the comparison of the measured flow rate and the theoretical fuel flow rate, and to correct the position setpoint of the nozzle according to the correction value.

The present disclosure provides a device for controlling a variable section ejection nozzle of a turbojet engine nacelle of an aircraft. The device includes a calculator adapted to determine a position setpoint of the nozzle and a management system of the servo-control of the position of the variable nozzle depending on the flow rate of the fuel supplying the turbojet engine. The management system includes at least one instantaneous flow rate sensor of the fuel and a management unit which is designed to compare the flow rate measured by the flow rate sensor with a theoretical fuel flow rate depending on the parameters of the flight of the aircraft, to determine a correction value of the position of the nozzle depending on the comparison of the measured flow rate and the theoretical fuel flow rate, and to correct the position setpoint of the nozzle according to the correction value.

A control system operable includes a modified primary control parameter for an aircraft, the control system includes: a primary control parameter leg configured to output a demand in an aircraft primary control parameter; a primary control parameter compensation leg configured to receive a change in absolute levels and/or spatial distributions of swirl angle and/or fan pressure at a primary control parameter relative to a reference and convert the change into the primary control parameter; a processor adapted to receive the demand in the primary control parameter output from the primary control parameter leg and the change to the primary control parameter output from the primary control parameter compensation leg; compare the demand in the primary control parameter output from the primary control parameter leg and the change to the primary control parameter output from the primary control parameter compensation leg; and generate a modified primary control parameter for the aircraft.

A method of estimating a parameter of a fluid flowing in a passage includes: having a plurality of instruments operable to measure one or more fluid properties flowing in the passage, the plurality of instruments being disposed in the passage and arranged within a common measurement plane; assigning a stream tube to each instrument, each stream tube represents a region of space in the common measurement plane within the passage and each stream tube surrounds one of the plurality of instruments, the stream tubes together correspond to the cross-sectional shape and area of the passage in the common measurement plane; measuring the one or more fluid properties using the instruments to obtain one or more measured values for each stream tube; using the measured value(s) for each stream tube to calculate a derived value for each stream tube; and summing the derived values across all of the stream tubes.

A turbofan engine has an engine core including in flow series a compressor, a combustor and a turbine. The engine further has a fan located upstream of the engine core, has a supersonic intake for slowing down incoming air to subsonic velocities at an inlet to the fan formed by the intake, has a bypass duct surrounding the engine core, wherein the fan generates a core airflow to the engine core and a bypass airflow through the bypass duct, and has a mixer for mixing an exhaust gas flow exiting the engine core and bypass airflow exiting bypass duct. The engine further has a thrust nozzle rearwards of the mixer for discharging mixed flows, the thrust nozzle having a variable area throat. The engine further has a controller controlling the thrust produced by the engine over a range of flight operations including on-the-ground subsonic take-off and subsequent off-the-ground subsonic climb.

A gas turbine engine has a fan case exit and an inner core housing exit. At least one of the exits is provided with a fiber optic sensing unit. The fiber optic sensing unit includes a fiber optic sensing member surrounding a circumference of the at least one of the exits. A control is programmed to calculate a nozzle area at the at least one of the exits based upon the displacement of the fiber optic sensing member. The calculated nozzle area is utilized to update nozzle area information at an electronic engine controller for the engine, and the electronic engine controller is programmed to control at least one associated component on a gas turbine engine based upon the updated nozzle area. A method is also disclosed.

A gas turbine engine has a fan case exit and an inner core housing exit. At least one of the exits is provided with a fiber optic sensing unit. The fiber optic sensing unit includes a fiber optic sensing member surrounding a circumference of the at least one of the exits. A control is programmed to calculate a nozzle area at the at least one of the exits based upon the displacement of the fiber optic sensing member. The calculated nozzle area is utilized to update nozzle area information at an electronic engine controller for the engine, and the electronic engine controller is programmed to control at least one associated component on a gas turbine engine based upon the updated nozzle area. A method is also disclosed.

Systems and methods for limiting power of a gas turbine engine for an aircraft are described herein. A blade angle of a propeller blade of the engine and a commanded power for the engine are obtained. A thrust transition direction is determined. The commanded power is compared to a selected threshold based on the blade angle and the thrust transition direction. Power to the engine is limited when the commanded power exceeds the selected threshold.