Abstract: A gas turbine engine includes, among other things, a propulsor section including a propulsor, a core engine, a gear arrangement that drives the propulsor. A compressor section includes a low pressure compressor and a high pressure compressor. A turbine section includes a high pressure turbine and a low pressure turbine. An overall pressure ratio is provided by the combination of a pressure ratio across the low pressure compressor and a pressure ratio across the high pressure compressor, and greater than 40. The pressure ratio across the high pressure compressor is between 7 and 15, and the pressure ratio across the low pressure compressor is between 4 and 8.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, propulsor means, first compression means, second compression means, reduction means for reducing a rotational speed of an output that drives the propulsor means relative to an input, first expansion means, and second expansion means. The reduction means includes an epicyclic gear system with a gear reduction. The gear system is straddle-mounted by first and second bearings on opposite sides of the gear reduction relative to an engine longitudinal axis.

Abstract: A gas turbine engine includes, among other things, a propulsor section including a propulsor, a core engine, a gear arrangement that drives the propulsor. A compressor section includes a first compressor section and a second compressor section. A turbine section includes a first turbine and a second turbine. An overall pressure ratio is provided by the combination of a pressure ratio across the first compressor section and a pressure ratio across the second compressor section, and greater than 40. The pressure ratio across the second compressor section is between 7 and 15, and the pressure ratio across the first compressor section is between 4 and 8.

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 gas turbine engine includes a propulsor with a power turbine, a power turbine shaft extending forward therefrom defining a centerline axis, and a fan driven by the power turbine shaft. The fan is aligned with the centerline axis forward of the power turbine and is operatively connected to be driven by the power turbine through the power turbine shaft. A gas generator operatively connected to the propulsor is included downstream from the fan and forward of the power turbine, wherein the gas generator defines a generator axis offset from the centerline axis. The gas generator is operatively connected to the power turbine to supply combustion products for driving the power turbine.

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, among other things, a propulsor section including a propulsor, a core engine, a gear arrangement that drives the propulsor. A compressor section includes a first compressor section and a second compressor section. A turbine section includes a first turbine and a second turbine. An overall pressure ratio is provided by the combination of a pressure ratio across the first compressor section and a pressure ratio across the second compressor section, and greater than 40. The pressure ratio across the second compressor section is between 7 and 15, and the pressure ratio across the first compressor section is between 4 and 8.

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 propulsor fan and drive system having reduced noise emission is disclosed. The propulsor fan includes a blade fan having a plurality of blades. The blades may include a dual pin-root design to secure the blade fan to a hub and a shroud at tips of the blades. The blades may include one or more knife edge seals that protrude from a surface of the shroud.

Abstract: A turbofan gas turbine engine includes, among other things, a fan section, a core engine, a bypass passage, and a bypass ratio defined as the volume of air passing into the bypass passage compared to the volume of air passing into the core engine, the bypass ratio being greater than or equal to 10. A gear arrangement drives the fan section. A compressor section includes a low pressure compressor section and a high pressure compressor section. A turbine section drives the gear arrangement. An overall pressure ratio is provided by the combination of a pressure ratio across the low pressure compressor section and a pressure ratio across the high pressure compressor section, and greater than 40. The pressure ratio across the high pressure compressor section is between 7 and 15, and the pressure ratio across the low pressure compressor section is between 4 and 8.

Abstract: An exemplary gas turbine engine assembly includes a fan section including a fan, a first spool having a first turbine operatively mounted to a first turbine shaft, and a second spool having a second turbine operatively mounted to a second turbine shaft. The first and second towershafts are respectively coupled to the first and second turbine shafts. An accessory drive gearbox includes a set of gears. A compressor is driven by the first towershaft. A transmission couples a starter generator assembly to the set of gears. The transmission is transitionable between a first mode where the starter generator assembly is driven at a first speed relative to the second towershaft in response to rotation of the second towershaft, and a second mode where the starter generator assembly is driven at a different, second speed relative to the second towershaft in response to rotation of the second towershaft.

Abstract: A gas turbine engine includes a plurality of rotating components housed within a compressor section and a turbine section. A tap connects to the compressor section. A heat exchanger connects downstream of the tap. A cooling compressor connects downstream of the heat exchanger, and the cooling compressor connects to deliver air to at least one of the rotating components. A core housing has an outer peripheral surface and a fan housing defines an inner peripheral surface. At least one bifurcation duct extends between the outer peripheral surface to the inner peripheral surface. The heat exchanger is disposed within the at least one bifurcation duct.

Abstract: A gas turbine engine includes a propulsor with a power turbine, a power turbine shaft extending forward therefrom defining a centerline axis, and a fan driven by the power turbine shaft. The fan is aligned with the centerline axis forward of the power turbine and is operatively connected to be driven by the power turbine through the power turbine shaft. A gas generator operatively connected to the propulsor is included downstream from the fan and forward of the power turbine, wherein the gas generator defines a generator axis offset from the centerline axis. The gas generator is operatively connected to the power turbine to supply combustion products for driving the power turbine.

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: An aircraft propulsion system includes a fan section that includes a fan shaft that is rotatable about a fan axis. The fan shaft includes a fan gear. The aircraft propulsion system also includes a boost turbine engine that includes a first output shaft that includes a first gear that is coupled to the fan gear. The boost turbine engine has a first maximum power capacity. The aircraft propulsion system further includes a cruise gas turbine engine that includes a second output shaft that includes a second gear that is coupled to the fan gear. The cruise turbine engine has a second maximum power capacity that is less than the first maximum power capacity of the boost turbine engine. The fan section produces a thrust that corresponds to power input through the fan gear from the boost turbine engine and the cruise turbine engine.

Abstract: A gas turbine engine includes a propulsor having a plurality of blades, a compressor section including a first compressor and a second compressor aft of the first compressor. The first compressor includes at least one array of first variable guide vanes that control operation of the first compressor. The second compressor includes at least one array of second variable guide vanes that control operation of the second compressor. A turbine section includes a first turbine and a second turbine. A geared architecture is driven by the second turbine for rotating the propulsor.

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 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.