Abstract: A gas turbine engine includes a propulsor section including a propulsor, a compressor section including a first compressor and a second compressor, a geared architecture, a turbine section including a first turbine and a drive turbine, and a power density of greater than or equal to 4.75 and less than or equal to 5.5 lbf/in3, wherein the power density is a ratio of a thrust provided by the engine to a volume of the turbine section.

Abstract: A gas turbine engine includes, among other things, a propulsor section including a rotor and blades, a gear train, a compressor section and a turbine section. A static structure includes a first case and a second case. The first case includes a first engine mount location. The second case includes a second engine mount location. The first engine mount location is axially near the gear train.

Abstract: A gas turbine engine includes a plurality of rotating components housed within a compressor section and a turbine section. A first tap is connected to the compressor section and configured to deliver air at a first pressure. A heat exchanger is connected downstream of the first tap. A flowpath is defined between a rotating surface and a non-rotating surface. The flowpath is connected downstream of the heat exchanger and is configured to deliver air to at least one of the plurality of rotating components. At least a portion of the non-rotating surface and the rotating surface includes a base metal. An insulation material is disposed on a surface along the flowpath.

Abstract: A gas turbine engine includes a plurality of rotating components housed within a compressor section and a turbine section. A first tap is connected to the compressor section and configured to deliver air at a first pressure. A heat exchanger is connected downstream of the first tap. A flowpath is defined between a rotating surface and a non-rotating surface. The flowpath is connected downstream of the heat exchanger and is configured to deliver air to at least one of the plurality of rotating components. At least a portion of the non-rotating surface and the rotating surface includes a base metal. An insulation material is disposed on a surface along the flowpath.

Abstract: A turbofan engine according to an example of the present disclosure includes, among other things, a fan, a compressor section, a turbine section including a fan drive turbine and a second turbine, an epicyclic gear system with a gear reduction, first and second bearings, and a fan drive shaft interconnecting the gear system and the fan. The fan drive turbine has a first exit area at a first exit point and is rotatable at a first speed. The second turbine has a second exit area at a second exit point and is rotatable at a second speed. A first performance quantity is defined as the product of the first speed squared and the first area. A second performance quantity is defined as the product of the second speed squared and the second area.

Abstract: An example gas turbine engine includes a propulsor assembly consisting of a propulsor and a first turbine. An epicyclic gear train defines a gear reduction ratio of greater than 2.3. A weight of the propulsor assembly is less than 40 percent of a total weight of the gas turbine engine, excluding any nacelle. A first spool includes a first shaft that connects a first compressor and the first turbine. The first shaft drives the propulsor through the gear train to drive the propulsor at a lower speed than the first spool. A second spool includes a second shaft connecting a second compressor and a second turbine. A weight of the propulsor is greater than a weight of the first turbine.

Abstract: A turbine engine includes a first compression section includes a last blade trailing edge radial tip length that is greater than about 67% of the radial tip length of a leading edge of a first stage of the first compression section. A second compression section includes a last blade trailing edge radial tip length that is greater than about 57% of a radial tip length of a leading edge of a first stage of the first compression section.

Abstract: A gas turbine engine includes a propulsor section including a propulsor, a compressor section including a first compressor and a second compressor, a geared architecture, a turbine section including a first turbine and a drive turbine, and a power density of greater than or equal to 4.75 and less than or equal to 5.5 lbf/in3, wherein the power density is a ratio of a thrust provided by the engine to a volume of the turbine section.

Abstract: A system is provided for alternating starter use during multi-engine motoring in an aircraft. The system includes a first engine starting system of a first engine. A first controller is in communication with a second controller that controls a second engine starting system of a second engine, the first controller being configured to intermittently direct power to the first engine starting system to alternately accelerate and decelerate the first engine during motoring with respect to the second engine.

Abstract: A turbofan engine has an engine case and a gaspath through the engine case. A fan has a circumferential array of fan blades. The engine further has a compressor, a combustor, a gas generating turbine, and a low pressure turbine section. A speed reduction mechanism couples the low pressure turbine section to the fan. A bypass area ratio is greater than about 6.0. The low pressure turbine section airfoil count to bypass area ratio is below about 170.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a propulsor section including a propulsor supported on a propulsor shaft, a turbine section including a turbine shaft, a compressor section having a plurality of compressor hubs with blades driven by the turbine shaft about an engine axis, and an epicyclic gear train interconnecting the propulsor shaft and the turbine shaft. The epicyclic gear train includes a sun gear coupled to the turbine shaft, intermediary gears arranged circumferentially about and meshing with the sun gear, a carrier and a ring gear including first and second portions. The first and second portions have axially opposed faces abutting one another at a radial interface.

Abstract: A gas turbine engine includes a compressor section and a turbine section operably coupled to the compressor section. The gas turbine engine further includes a means for selectively releasing a cooling fluid flow produced at a cryogenic temperature and a plumbing system in fluid communication with the means for selectively releasing the cooling fluid flow. The plumbing system is configured to route the cooling fluid flow to one or more of the compressor section and the turbine section.

Abstract: A gas turbine engine includes, among other things, a propulsor section including a rotor, a gear train, a low spool and a high spool. A static structure includes a first case and a second case. A mount system includes a forward mount and an aft mount arranged in a plane containing an engine axis of rotation. The forward mount is secured to the first case. The aft mount is secured to the second case.

Abstract: A gas turbine engine has a compressor section and a turbine section. A secondary cooling air includes a first fluid connection to tap cooling air and pass the cooling air through a plurality of tubes, and a second fluid connection for returning air from the tubes back to at least one of the compressor and turbine for cooling. A sensor senses a condition of the cooling air downstream of the tubes and a control compares the sensed condition of the cooling air to an expected condition, and to identify a potential concern in the cooling air system should the sensed condition differ from the expected condition by more than a predetermined amount.

Abstract: A turbofan engine includes a propulsor section that has a propulsor shaft in driving engagement with a propulsor. An epicyclic gear system has a gear mesh lateral stiffness and a gear mesh transverse stiffness. A gear system input 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 turbine section rotates at a first speed, and a second turbine rotates at a second speed that is faster than the first speed. A first performance quantity is defined as the product of the first speed squared and the first area of the first turbine, a second performance quantity is defined as the product of the second speed squared and the second area of the second turbine, and a performance quantity ratio is between 0.5 and 1.5.

Abstract: A gas turbine engine includes a compressor section including a first compressor, a turbine section including a first turbine and a second turbine, a first shaft and a second shaft, the first shaft interconnecting the first turbine and the second compressor, and a geared architecture. The first shaft is supported on a first bearing in an overhung manner. A performance ratio 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 propulsor section including a propulsor supported on a propulsor shaft, a turbine section including a turbine shaft, a compressor section, and an epicyclic gear train interconnecting the propulsor shaft and the turbine shaft. The gear train includes a sun gear coupled to the turbine shaft, intermediary gears arranged circumferentially about and meshing with the sun gear, a carrier supporting the intermediary gears, and a ring gear including first and second portions each having an inner periphery with teeth intermeshing with the intermediate gears. The first and second portions have axially opposed faces abutting one another at a radial interface. The first and second portions have grooves at the radial interface that form a hole that expels oil through the ring gear.

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 aspect of the present disclosure includes, among other things, a fan and a braking system. The braking system is configured to selectively engage the fan during ground windmilling to apply a first level of braking to slow rotation of the fan. Further, when the rotation of the fan sufficiently slows, the braking system is further configured to apply a second level of braking more restrictive than the first level of braking.

Abstract: A system is provided for multi-engine coordination of gas turbine engine motoring in an aircraft. The system includes a controller operable to determine a motoring mode as a selection between a single engine dry motoring mode and a multi-engine dry motoring mode based on at least one temperature of a plurality of gas turbine engines and initiate dry motoring based on the motoring mode.