Abstract: According to an example embodiment, a gas turbine engine assembly includes, among other things, a fan section including a fan, the fan including a plurality of fan blades, a diameter of the fan having a dimension D that is based on a dimension of the fan blades, each fan blade having a leading edge, and a forward most portion on the leading edges of the fan blades in a first reference plane, a geared architecture, a turbine section including a high pressure turbine and a low pressure turbine, the low pressure turbine driving the fan through the geared architecture, a nacelle surrounding the fan, the nacelle including an inlet portion forward of the fan, a forward edge on the inlet portion in a second reference plane, and a length of the inlet portion having a dimension L measured along an engine axis between the first reference plane and the second reference plane. A dimensional relationship of L/D is between 0.20 and 0.40.

Abstract: In accordance with one aspect of the disclosure, a gas turbine engine, method of using and designing such is disclosed. The gas turbine engine may comprise a fan including a plurality of blades, and a variable area fan nozzle. The fan may be configured to have a design point fan tip leading edge relative flow angle ?ADP, and may be further configured to have an off-design point fan tip leading edge relative flow angle ? at an off-design fan operating point. The variable area fan nozzle may be configured to manipulate the amount of air flowing through the fan so that the absolute value of a difference between the design point fan tip leading edge relative flow angle ?ADP and the off-design point fan tip leading edge relative flow angle ? is in a specified range.

Abstract: A propulsion system for an aircraft includes a furcated nozzle that has at least a first duct that extends from a first propulsor to a first trailing end duct opening and a second duct that extends from a second propulsor to a second trailing end duct opening.

Abstract: A fan assembly for a gas turbine engine includes a fan including a plurality of fan blades extending radially outwardly from a fan hub to a blade tip defining a fan diameter. A nacelle surrounds the fan and defines a fan inlet upstream of the fan, relative to an airflow direction into the fan. The nacelle has a forwardmost edge defining an inlet length from the forwardmost edge to a leading edge of a fan blade. A ratio of inlet length to fan diameter is between 0.20 and 0.45. A nacelle inner surface defines a nacelle flowpath having a convex throat portion and a diffusion portion between the throat portion and the leading edge of the fan blade at a topmost portion of the nacelle. The throat portion has a minimum throat radius measured from a fan central axis greater than a blade tip radius.

Abstract: A cross flow fan to be incorporated into an aircraft fuselage comprises an ingestion fan rotor to be positioned in a tail section of an aircraft fuselage to reduce boundary layer air from a top surface of the fuselage and to drive the air away from the top surface, and a drive arrangement for the ingestion fan rotor. An aircraft is also disclosed.

Abstract: An aircraft is provided that includes a wing and a pusher fan engine. The pusher fan engine is configured in the wing.

Abstract: A drive arrangement for an aircraft comprises a pair of propulsor units each having a fan and a fan shaft for driving the fan. A core engine has a turbine driving a core engine shaft. A mechanical connection connects the core engine shaft to drive the fan shafts for each of the propulsor units. An aircraft also has such an arrangement.

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 fan nozzle for an aircraft gas turbine engine is comprised of a core engine cowl that is disposed within a fan cowl so that an air flow area is defined therebetween. The core engine cowl and fan cowl are disposed around a horizontal central plane. The fan cowl has a substantially circular shape and is formed of an upper substantially semi-circular portion having a first radius and a lower substantially semi-circular portion having a second radius. The core engine cowl has a substantially circular shape and is formed of an upper substantially semi-circular portion having a third radius and a lower substantially semi-circular portion having a third radius. The upper substantially semi-circular portion of the core engine cowl includes a left arcuate member and a right arcuate member. The second radius is less than the first radius and the third radius is less than the fourth radius.

Abstract: In a featured embodiment, a gas turbine engine has a first compressor rotor driven by a first turbine rotor, and a second compressor rotor driven by a second turbine rotor. The second compressor rotor is upstream of the first compressor rotor and the first turbine rotor is upstream of the second turbine rotor. An air mixing system taps air from a location upstream of the first compressor rotor for delivery to an environmental control system. The air mixing system receives air from a first air source and a second air source. The first air source includes air at a first pressure upstream of the first compressor rotor. The second air source includes air at a lower second pressure. At least one valve controls a mixture of air from the first and second sources to achieve a predetermined pressure for the environmental control system.

Abstract: According to an example embodiment, a gas turbine engine assembly includes, among other things, a fan section including a fan, the fan including a plurality of fan blades, a diameter of the fan having a dimension D that is based on a dimension of the fan blades, each fan blade having a leading edge, and a forward most portion on the leading edges of the fan blades in a first reference plane, a geared architecture, a turbine section including a high pressure turbine and a low pressure turbine, the low pressure turbine driving the fan through the geared architecture, a nacelle surrounding the fan, the nacelle including an inlet portion forward of the fan, a forward edge on the inlet portion in a second reference plane, and a length of the inlet portion having a dimension L measured along an engine axis between the first reference plane and the second reference plane. A dimensional relationship of L/D is no more than 0.45.

Abstract: A method comprises the steps of modifying an existing engine which includes a high pressure compressor driven by a high pressure turbine and a low pressure turbine to drive a low pressure compressor. The modifying step includes utilizing the high pressure compressor as a low pressure compressor in a modified gas turbine engine, and designing and incorporating a new high pressure compressor downstream of the low pressure compressor section in the modified engine, such that a portion of the design of the existing engine is utilized in the modified engine. A gas turbine engine is also disclosed.

Abstract: A gas turbine engine includes a core engine assembly including a compressor section communicating air to a combustor section where the air is mixed with fuel and ignited to generate a high-energy gas flow that is expanded through a turbine section. The turbine section is coupled to drive the compressor section. A propulsor section aft of the core engine is driven by the turbine section. An exhaust duct routing exhaust gases around the propulsor section. The exhaust duct includes an inlet forward of the propulsor section, an outlet aft of the turbine section and a passageway between the inlet and the outlet. An aircraft and exhaust duct are also disclosed.

Abstract: A turbofan engine according to an example of the present disclosure includes, among other things, 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: The present disclosure relates generally to a gas turbine engine that includes a fan configured to generate a fanstream and a fanstream duct configured to receive the fanstream flowing therethrough. An engine electronic component is positioned in flow communication with the fanstream. A heating element is positioned in the fanstream upstream from the engine electronic component and is operative to heat at least a portion of the fanstream in flow communication with the engine electronic component. The position of the engine electronic component passively thermally conditions the engine electronic component and the heating element actively thermally conditions the engine electronic component.

Abstract: A fan section for a gas turbine engine according to an example of the present disclosure includes, among other things, a fan rotor having fan blades, and a plurality of fan exit guide vanes positioned downstream of the fan rotor. The fan rotor is configured to be driven through a gear reduction. A ratio of a number of fan exit guide vanes to a number of fan blades is defined. The fan exit guide vanes are provided with optimized sweep and optimized lean.

Abstract: A turbofan engine according to an example of the present disclosure includes, among other things, a fan including a circumferential array of fan blades, a compressor in fluid communication with the fan, the compressor including a first compressor section and a second compressor, the second compressor section including a second compressor section inlet with a second compressor section inlet annulus area, a fan duct including a fan duct annulus area outboard of the second compressor section inlet, a shaft assembly having a first portion and a second portion, a turbine in fluid communication with the combustor, the turbine having a first turbine section coupled to the first portion of the shaft assembly to drive the first compressor section, and a second turbine section coupled to the second portion of the shaft assembly to drive the fan, an epicyclic transmission coupled to the fan and rotatable by the second turbine section through the second portion of the shaft assembly to allow the second turbine to turn fa

Abstract: A turbofan engine according to an example of the present disclosure includes, among other things, a fan including an array of fan blades rotatable about an engine axis, a compressor including a first compressor section and a second compressor section, the second compressor section including a second compressor section inlet with a compressor inlet annulus area, a fan duct including a fan duct annulus area outboard of the second compressor section inlet, and a turbine having a first turbine section driving the first compressor section, a second turbine section driving the fan through an epicyclic gearbox, the second turbine section including blades and vanes, and wherein the second turbine section defines a maximum gas path radius and the fan blades define a maximum radius, and a ratio of the maximum gas path radius to the maximum radius of the fan blades is less than 0.6.

Abstract: An exemplary boundary layer ingestion engine includes a gas generator, a turbine fluidly connected to the gas generator, and a fan mechanically linked to the turbine via at least one shaft. The linkage is configured such that rotation of the turbine is translated to the fan. The boundary layer ingestion engine further includes an exhaust duct fluidly connected to an outlet of the turbine. The exhaust duct is positioned radially inward of the fan.

Abstract: A fan section for a gas turbine engine according to an example of the present disclosure includes, among other things, a fan rotor having fan blades, and a plurality of fan exit guide vanes positioned downstream of the fan rotor. The fan rotor is configured to be driven through a gear reduction. A ratio of a number of fan exit guide vanes to a number of fan blades is defined. The fan exit guide vanes are provided with optimized sweep and optimized lean.