An air bypass system for a gas turbine engine includes a nozzle for a gas turbine engine. The air bypass system includes the nozzle having an inner band, an outer band, and an airfoil extending between the inner band and the outer band. The airfoil defines an internal passage. A diaphragm includes an inner wall, a first rail, and a second rail, which collectively define a diaphragm cavity. The first rail defines a first rail aperture. A manifold is positioned in the diaphragm cavity. The manifold and the diaphragm collectively define a manifold chamber in fluid communication with the first rail aperture. A tube extends through the internal passage defined by the airfoil and into the diaphragm cavity. The tube is in fluid communication with the manifold chamber. Compressed air flows through the tube into the manifold chamber and exits the chamber through the first rail aperture.

An actuator system including a harmonic drive operable to drive a variable vane system of a gas turbine engine.

An actuator system including a harmonic drive operable to drive a variable vane system of a gas turbine engine.

An air intake for efficiently channeling a flow of ambient air toward an air inlet of a turboprop or turboshaft gas turbine engine is disclosed. The air intake comprises an intake inlet for receiving the flow of air, an intake duct for channelling the flow of air, and an intake outlet for discharging the flow of air toward the air inlet of the gas turbine engine. The intake duct may be oriented toward a flow direction of the air pushed aft by a propeller coupled to the gas turbine engine.

A highly efficient gas turbine engine is provided. The fan of the gas turbine engine is driven from a turbine via a gearbox, such that the fan has a lower rotational speed than the driving turbine, thereby providing efficiency gains. The efficient fan system is mated to a core that has low cooling flow requirements and/or high temperature capability, and which may have particularly low mass for a given power.

A method of modulating cooling flow to an engine component based on a health of the component is provided. The method includes determining a cooling flow requirement of the engine component for each of a plurality of operating conditions and channeling the determined required flow to the engine component during each respective operating condition of the plurality of operating conditions. The method also includes assessing a health of the engine component. The method further includes modifying the determined cooling flow requirement based on the assessed health of the engine component, and supplying the modified cooling flow requirement to the engine component during each subsequent respective operating condition of the plurality of operating conditions.

A method of modulating cooling flow to an engine component based on a health of the component is provided. The method includes determining a cooling flow requirement of the engine component for each of a plurality of operating conditions and channeling the determined required flow to the engine component during each respective operating condition of the plurality of operating conditions. The method also includes assessing a health of the engine component. The method further includes modifying the determined cooling flow requirement based on the assessed health of the engine component, and supplying the modified cooling flow requirement to the engine component during each subsequent respective operating condition of the plurality of operating conditions.

A cooling system is disclosed for cooling charge air in a turbocharged diesel internal combustion engine of an aircraft. The cooling system includes a charge air cooler, a charge air bypass valve, and a bypass valve actuator. The charge air cooler is fluidly coupled between the turbocharger assembly and the intake manifold, wherein the charge air cooler is configured to cool the charge air. The charge air bypass valve is moveable between a first position and a second position. The charge air bypass valve is configured to bypass the charge air cooler when in the second position. The bypass valve actuator is configured to move the charge air bypass valve between the first position and the second position.

A cooling system is disclosed for cooling charge air in a turbocharged diesel internal combustion engine of an aircraft. The cooling system includes a charge air cooler, a charge air bypass valve, and a bypass valve actuator. The charge air cooler is fluidly coupled between the turbocharger assembly and the intake manifold, wherein the charge air cooler is configured to cool the charge air. The charge air bypass valve is moveable between a first position and a second position. The charge air bypass valve is configured to bypass the charge air cooler when in the second position. The bypass valve actuator is configured to move the charge air bypass valve between the first position and the second position.

A gas turbine engine includes a core flowpath for flowing a core stream, a second flowpath located radially outward from the core flowpath for flowing a second stream, and an auxiliary flowpath located radially outward from the second flowpath for flowing an auxiliary stream. A heat exchanging device is constructed and arranged to divert a portion of the second stream into the auxiliary flowpath. A turbine exhaust case is constructed and arranged to flow the auxiliary stream into the core flowpath for mixing with the core stream.