Abstract: A gas turbine engine according to an exemplary embodiment of this disclosure includes among other possible things, a fan section including a plurality of fan blades, a first electric motor assembly that provides a first drive input for driving the fan blades about an axis, a turbine section, and a geared architecture driven by the turbine section and coupled to the fan section to provide a second drive input for driving the fan blades, and second electric motor assembly is coupled to rotate the geared architecture relative to a fixed structure controls a speed of the fan blades provided by a combination of the first drive input and the second drive input.

Abstract: An aircraft propulsion system is disclosed and includes a first gas turbine engine including a first input shaft driving a first gear system, a first fan driven by the first gear system, a first generator supported on the first input shaft and a fan drive electric motor providing a drive input to the first fan, a second gas turbine engine including a second input shaft driving a second gear system, a second fan driven by the second gear system, a second generator supported on the second input shaft and a second fan drive electric motor providing a drive input to the second fan and a controller controlling power output from each of the first and second generators and directing the power output between each of the first and second fan drive electric motors.

Abstract: An airfoil cooling system may include an airfoil that defines a first cooling chamber and a second cooling chamber. The first cooling chamber may be configured to receive a first cooling airflow from a first fluid source and the second cooling chamber may be configured to receive a second cooling airflow from a second fluid source that is different from the first fluid source. The airfoil may be a vane of a gas turbine engine. For example, the vane may be a first vane of a plurality of vanes of a turbine section of the gas turbine engine. The first cooling chamber may be a leading edge chamber of the first vane and the second cooling chamber may be an aft chamber of the first vane that is positioned aft of the leading edge chamber.

Abstract: A gas turbine engine includes a first spool, a second spool, a primary combustor, and a diffuser. The first spool includes a first compressor rotationally driven by a first turbine via a first shaft. The second spool includes a second compressor driven by a second turbine via a second shaft. The first compressor, the diffuser, and the primary combustor are arranged in series to provide a compressed airflow discharged from the first compressor to the primary combustor via the diffuser, which includes walls that diverge towards the primary combustor. The second compressor is fluidly coupled to the diffuser to receive at least a portion of the compressed airflow from the diffuser. The second turbine is fluidly coupled to the diffuser to discharge an expanded airflow to the diffuser.

Abstract: A turbine engine includes integrated electric machines in the compressor section and the turbine section to supplement power produced from fuel with electric power. The example compressor section includes a compressor electric motor that is coupled to a compressor generator. The example turbine section includes a turbine electric motor that is coupled to the geared architecture to supplement power driving the fan section. A turbine generator provides electric power to the turbine electric motor.

Abstract: A turbofan engine includes a fan section that drives air along a bypass flow path in a bypass duct. An epicyclic gear system in driving engagement with the fan shaft and has a gear mesh lateral stiffness and a gear mesh transverse stiffness. A gear system input to the gear system defines a gear system input lateral stiffness and a gear system input transverse stiffness. The gear system input lateral stiffness is less than 5% of the gear mesh lateral stiffness. A first performance quantity is defined as the product of a first speed squared and a first area and a second performance quantity is defined as the product of a second speed squared and a second area. A performance quantity ratio of a first performance quantity to a second performance quantity is between 0.5 and 1.5.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a fan section including a fan having a plurality of fan blades, and a nacelle surrounding the plurality of fan blades, a compressor section including a low pressure compressor and a high pressure compressor, the low pressure compressor including a plurality of stages, and the high pressure compressor including 6 or more stages. A turbine section includes a fan drive turbine that drives the fan section through a gear arrangement, and including a second turbine that drives the high pressure compressor. A power ratio is provided by the combination of a first power input of the low pressure compressor and a second power input of the high pressure compressor, the power ratio defined by the second power input divided by the first power input, and the power ratio is less than or equal to 1.0.

Abstract: An after-fan system for an engine may comprise an after-fan turbine an electrical generator operationally coupled to the after-fan turbine, and an electric motor electrically coupled to the electrical generator. The electrical generator may be configured to generate an electrical current in response to rotation of the after-fan turbine. The electric motor may be configured to generate torque.

Abstract: A gas turbine engine includes an engine spool with a turbine section, a propeller, a motor, and a variable drive arrangement. The variable drive arrangement mechanically couples the engine spool to the propeller, and includes a first gear connection rotationally coupled to the propeller, a second gear connection rotationally coupled to the engine spool, and a sprag clutch rotationally coupled to the first gear connection. The sprag clutch is configured to passively decouple the motor from the first gear connection when a torque input from the engine spool exceeds a torque input from the motor, and is configured to passively couple the motor to the first gear connection when the torque input from motor exceeds a torque input from the engine spool.

Abstract: An aircraft propulsion system is disclosed and includes a first gas turbine engine including a first input shaft driving a first gear system, a first fan driven by the first gear system, a first generator supported on the first input shaft and a fan drive electric motor providing a drive input to the first fan, a second gas turbine engine including a second input shaft driving a second gear system, a second fan driven by the second gear system, a second generator supported on the second input shaft and a second fan drive electric motor providing a drive input to the second fan and a controller controlling power output from each of the first and second generators and directing the power output between each of the first and second fan drive electric motors.

Abstract: A gas turbine engine according to an exemplary embodiment of this disclosure includes, among other possible things, a fan including a plurality of fan blades rotatable about an axis, a plurality of inlet guide vanes mounted forward of the plurality of fan blades, the plurality of inlet guide vanes selectively rotatable about the axis independent of the plurality of fan blades; and a motor for controlling rotation of the plurality of inlet guide vanes about the axis.

Abstract: A hybrid electric gas turbine engine includes a fan section having a fan, a turbine section having a turbine drivably connected to the fan through a main shaft that extends along a central longitudinal axis, a gas generating core extending along a first axis that is radially offset from the central longitudinal axis, a first electric motor drivably connected to the main shaft, wherein the electric motor is colinear with the main shaft, and an electric compressor extending along a second axis that is radially offset from the central longitudinal axis, the electric compressor in fluid communication with the second turbine section.

Abstract: A gas turbine engine includes a gear system that provides a speed reduction between a fan drive turbine and a fan rotor. Aspects of the gear system are provided with some flexibility. The fan drive turbine has a first exit area and rotates at a first speed. A second turbine section has a second exit area and rotates at a second speed, which is faster than said first speed. A performance quantity can be defined for both turbine sections as the products of the respective areas and respective speeds squared. A performance quantity ratio of the performance quantity for the fan drive turbine to the performance quantity for the second turbine section is relatively high.

Abstract: A hybrid electric gas turbine engine includes a fan section having a fan, a turbine section having a turbine drivably connected to the fan through a main shaft that extends along a central longitudinal axis, a gas generating core extending along a first axis that is radially offset from the central longitudinal axis, a first electric motor drivably connected to the main shaft, wherein the electric motor is colinear with the main shaft, and an electric compressor extending along a second axis that is radially offset from the central longitudinal axis, the electric compressor in fluid communication with the second turbine section.

Abstract: A gas turbine engine turbine has a high pressure turbine configured to rotate with a high pressure compressor as a high pressure spool in a first direction about a central axis and a low pressure turbine configured to rotate with a low pressure compressor as a low pressure spool in the first direction about the central axis. A power density is greater than or equal to about 1.5 and less than or equal to about 5.5 lbf/cubic inches. A fan is connected to the low pressure spool via a speed changing mechanism and rotates in the first direction.

Abstract: A system for bleeding air from a core flow path of a gas turbine engine includes a bleed valve in a bleed air duct configured to receive bleed air from a first entrance point to the core flow path into the bleed air duct; a pressurized air valve in a pressurized air duct configured to receive pressurized air from a second entrance point to the core flow path, the pressurized air at a pressure greater than that received into the first entrance point; an eductor outlet from the pressurized air duct located in the bleed air duct; and a control system operable to control operation of the bleed valve and the pressurized air valve.

Abstract: A gas turbine engine includes a gear system that provides a speed reduction between a fan drive turbine and a fan rotor. Aspects of the gear system are provided with defined flexibility. The fan drive turbine has a first exit area and rotates at a first speed. A second turbine section has a second exit area and rotates at a second speed, which is faster than said first speed. A performance quantity can be defined for both turbine sections as the products of the respective areas and respective speeds squared. A performance quantity ratio of the performance quantity for the fan drive turbine to the performance quantity for the second turbine section is between 0.5 and 1.5.

Abstract: A turbofan engine includes a fan section including a plurality of fan blades, a first spool including a first turbine section, a second spool including a second turbine section, a first electric machine, and a second electric machine. A gear system is coupled between the first spool, the second spool, the first electric machine, the second electric machine and the fan section for driving the fan section.

Abstract: A multi-engine system includes a first gas turbine engine that includes a first compressor and a first turbine. The multi-engine system may further include a second gas turbine engine that has a second compressor and a second turbine. Still further, the multi-engine system may include a first crossover cooling network configured to route a first crossover airflow from the first compressor of the first gas turbine engine to the second turbine of the second gas turbine engine and a second crossover cooling network configured to route a second crossover airflow from the second compressor of the second gas turbine engine to the first turbine of the first gas turbine engine.

Abstract: An aircraft gas turbine engine system comprises first and second gas turbine engines connected by an inter-engine gas path. The first gas turbine engine has a first spool with a first compressor section, and a second spool with a second compressor section downstream of and rotationally independent from the first compressor section. The second gas turbine engine is configured to provide power to at least one of the first and second spools of the first gas turbine engine. The inter-engine gas path is disposed to receive gas flow bled from a bleed location in the first gas turbine engine downstream of the first compressor section, and to supply this gas flow to an inlet of the second gas turbine engine.