Abstract: An exhaust nozzle assembly for a propulsion system include a primary nozzle, an outer shroud, an ejector nozzle, and an actuator. The primary nozzle extends along an exhaust centerline. The primary nozzle includes a downstream axial end. The outer shroud surrounds the primary nozzle. The ejector nozzle extends axially between a first axial end and a second axial end. The second axial end forms a nozzle exit plane for the exhaust nozzle assembly. The ejector nozzle converges in a direction from the first axial end to the second axial end. The ejector nozzle forms a mixing cross-sectional area between the primary nozzle and the ejector nozzle at the downstream axial end. The actuator is mounted on the ejector nozzle. The actuator is configured to move the ejector nozzle between a first position and a second position, relative to the outer shroud, to control an area of the mixing cross-sectional area.

Abstract: Aircraft power plants including hydrogen turbo-expanders, and associated methods are provided. One method of operating an aircraft power plant includes: driving a load onboard an aircraft with a combustion engine; heating a solid metal hydride onboard the aircraft to cause hydrogen gas to be released from the solid metal hydride; expanding the hydrogen gas through a turbo-expander to produce work; and using the work produced by the turbo-expander to drive the load.

Abstract: There is provided an exhaust mixer arrangement for a turbofan engine having a bypass passage for channelling a bypass flow and a core passage for channelling a core flow around a central axis. The exhaust mixer arrangement comprises a mixer body mounted for rotation about the central axis. The mixer body has an annular wall extending around the central axis. The annular wall defines a plurality of circumferentially distributed alternating inner and outer lobes, with each inner lobe protruding into the core passage, and each outer lobe protruding into the annular bypass passage. A driving unit is operatively connected to the mixer body for selectively driving the mixer body in rotation about the central axis. A controller is operatively connected to the driving unit for controlling a rotational speed of the mixer body as a function of a flight operating condition.

Abstract: A method and a system for synthesizing output power provided by an engine are provided. The engine comprising a compressor section, a combustor, and a turbine section in serial fluid flow communication. The engine is operated and, during the operating of the engine, a pressure of fluid at an exit of the compressor section, a temperature upstream of the exit of the compressor section, and a fuel flow rate to the engine are determined. A synthesized value of output power provided by the engine is determined based on a product of at least a first factor, a second factor, and a third factor, the first factor being a function of the pressure, the second factor being a function of the temperature, and the third factor being a function of the fuel flow rate. The synthesized value of output power provided by the engine is output.

Abstract: A method and a system for synthesizing output power provided by an engine are provided. The engine comprising a compressor section, a combustor, and a turbine section in serial fluid flow communication. The engine is operated and, during the operating of the engine, a pressure of fluid at an exit of the compressor section, a temperature upstream of the exit of the compressor section, and a fuel flow rate to the engine are determined. A synthesized value of output power provided by the engine is determined based on a product of at least a first factor, a second factor, and a third factor, the first factor being a function of the pressure, the second factor being a function of the temperature, and the third factor being a function of the fuel flow rate. The synthesized value of output power provided by the engine is output.

Abstract: A method and a system for synthesizing thrust from a turbofan engine are provided. The turbofan engine comprising a compressor section, a combustor, and a turbine section in serial fluid flow communication. The engine is operated and, during the operating of the turbofan engine, a pressure of fluid at an exit of the compressor section and a temperature of fluid at a location upstream of the exit of the compressor section are determined. A synthesized value of thrust from the turbofan engine is determined based on a product of at least a first factor and a second factor, the first factor being a function of the pressure and the second factor being a function of the temperature. The synthesized value of thrust from the turbofan engine is output.

Abstract: A method and a system for synthesizing thrust from a turbofan engine are provided. The turbofan engine comprising a compressor section, a combustor, and a turbine section in serial fluid flow communication. The engine is operated and, during the operating of the turbofan engine, a pressure of fluid at an exit of the compressor section and a temperature of fluid at a location upstream of the exit of the compressor section are determined. A synthesized value of thrust from the turbofan engine is determined based on a product of at least a first factor and a second factor, the first factor being a function of the pressure and the second factor being a function of the temperature. The synthesized value of thrust from the turbofan engine is output.

Abstract: A variable geometry inlet system of an aircraft engine includes an inlet duct. The inlet duct includes at least first and second sections moveable between extended and retracted positions such that the inlet duct defines a variable axial length of an inlet passage for selective flight conditions. The inclusion of acoustic treatment may assist in controlling noise.

Abstract: An aircraft includes one or more engines configured to generate high-pressure bleed air and low-pressure bleed air. An aircraft environmental control system (ECS) is in fluid communication with one or more of the engines to receive the high-pressure bleed air and the low-pressure bleed air. The ECS calculates a synthesized low-pressure value associated with the low-pressure bleed air while still providing bleed air using the high pressure bleed air. The ECS further switches from the high pressure bleed air to the low-bleed pressure air through the ECS while blocking flow of the high-pressure bleed air through the ECS based on the synthesized low-pressure value.

Abstract: A variable geometry inlet system of an aircraft engine includes an inlet duct. The inlet duct includes at least first and second sections moveable between extended and retracted positions such that the inlet duct defines a variable axial length of an inlet passage for selective flight conditions. The inclusion of acoustic treatment may assist in controlling noise.

Abstract: A variable geometry inlet system of an aircraft engine includes an inlet duct. The inlet duct includes at least first and second sections moveable between extended and retracted positions such that the inlet duct defines a variable axial length of an inlet passage for selective flight conditions. The inclusion of acoustic treatment may assist in controlling noise.

Abstract: The present disclosure provides a method and a system for controlling operation of an engine of an aircraft. The method comprises, at a controller of the engine, obtaining an actual engine output power for the engine, the actual engine output power based on a propeller rotation speed and a propeller blade pitch angle; converting the actual engine output power to a predicted thrust value; determining an actual engine power limit associated with a thrust limit of a propeller coupled to the engine from the predicted thrust value; and setting a maximum engine power limit of the engine using the actual engine power limit associated with the thrust limit of the propeller.

Abstract: The present disclosure provides a method and a system for controlling operation of an engine of an aircraft. The method comprises, at a controller of the engine, obtaining an actual engine output power for the engine, the actual engine output power based on a propeller rotation speed and a propeller blade pitch angle; converting the actual engine output power to a predicted thrust value; determining an actual engine power limit associated with a thrust limit of a propeller coupled to the engine from the predicted thrust value; and setting a maximum engine power limit of the engine using the actual engine power limit associated with the thrust limit of the propeller.

Abstract: The present disclosure provides a method and a system for controlling operation of an engine of an aircraft. A first engine power limit associated with a thrust limit for a propeller coupled to the engine is obtained. The first engine power limit is compared to a second engine power limit associated with a mechanical limit for the engine and to a third engine power limit associated with a thermal limit for the engine. A maximum engine power limit is set at a lowest value of the first, second, and third engine power limits.

Abstract: An aircraft includes one or more engines configured to generate high-pressure bleed air and low-pressure bleed air. An aircraft environmental control system (ECS) is in fluid communication with one or more of the engines to receive the high-pressure bleed air and the low-pressure bleed air. The ECS calculates a synthesized low-pressure value associated with the low-pressure bleed air while still providing bleed air using the high pressure bleed air. The ECS further switches from the high pressure bleed air to the low-bleed pressure air through the ECS while blocking flow of the high-pressure bleed air through the ECS based on the synthesized low-pressure value.

Abstract: A variable geometry inlet system of an aircraft engine includes an inlet duct. The inlet duct includes at least first and second sections moveable between extended and retracted positions such that the inlet duct defines a variable axial length of an inlet passage for selective flight conditions. The inclusion of acoustic treatment may assist in controlling noise.

Abstract: A variable geometry inlet system of an aircraft engine includes an inlet duct. The inlet duct includes at least first and second sections moveable between extended and retracted positions such that the inlet duct defines a variable axial length of an inlet in controlling noise.

Abstract: An aeroengine has an inlet system with a forward end with respect to a flight direction. The inlet system includes a main inlet duct for selectively directing a first air flow from a forward main intake opening of the main inlet duct to a compressor rotor, the forward main intake opening being defined at the forward end of the inlet system and a secondary inlet duct for directing a second air flow from a secondary intake opening of the secondary inlet duct to the compressor rotor only when the main inlet duct is closed. A control apparatus is provided for selecting the first and second air flow to enter into the compressor rotor.

Abstract: An aeroengine has an inlet system with a forward end with respect to a flight direction. The inlet system includes a main inlet duct for selectively directing a first air flow from a forward main intake opening of the main inlet duct to a compressor rotor, the forward main intake opening being defined at the forward end of the inlet system and a secondary inlet duct for directing a second air flow from a secondary intake opening of the secondary inlet duct to the compressor rotor only when the main inlet duct is closed. A control apparatus is provided for selecting the first and second air flow to enter into the compressor rotor.

Abstract: The present disclosure provides a method and a system for controlling operation of an engine of an aircraft. A first engine power limit associated with a thrust limit for a propeller coupled to the engine is obtained. The first engine power limit is compared to a second engine power limit associated with a mechanical limit for the engine and to a third engine power limit associated with a thermal limit for the engine. A maximum engine power limit is set at a lowest value of the first, second, and third engine power limits.