A turbomachine engine can include a fan assembly, a vane assembly, a core engine, a gearbox, and an overall engine efficiency rating. The fan assembly can include a plurality of fan blades. The vane assembly can include a plurality of vanes, and the vanes can, in some instances, be disposed aft of the fan blades. The core engine can include a low-pressure turbine. The gearbox includes an input and an output. The input of the gearbox is coupled to the low-pressure turbine of the core engine and comprises a first rotational speed, the output of the gearbox is coupled to the fan assembly and has a second rotational speed, and a gear ratio of the first rotational speed to the second rotational speed is within a range of 3.2-4.0. The overall engine efficiency rating is within a range of 0.57-8.0.

A gear assembly for use with a turbomachine comprises a sun gear, a plurality of planet gear layshafts that each support a first stage planet gear and a second stage planet gear, and a ring gear. The sun gear is configured to rotate about a longitudinal centerline of the gear assembly, and the plurality of planet gear layshafts have a tubular shape.

A gearbox for an engine includes a rotating element and a turbomachine, the turbomachine includes a shaft, and the rotating element is driven by the shaft across the gearbox. The gearbox includes a ring gear, a first sun gear and a second sun gear each configured to be driven by the shaft of the turbomachine, a first planet gear comprising a first gear portion and a second gear portion, and a second planet gear comprising a first gear portion and a second gear portion.

A compressor adapted for use in for a gas turbine engine includes a diffuser and a housing. The diffuser is arranged circumferentially around an axis and includes a fore plate, an aft plate spaced apart axially from the fore plate to define a flow path therebetween, and a plurality of vanes that extend between the fore plate and the aft plate. The housing is arranged circumferentially about the axis and located adjacent the diffuser.

A hybrid propulsion system is provided. The system may comprise a gas turbine engine and a secondary engine, an inlet, an exhaust, a pressurized tank, and an expansion valve. The inlet may be in fluid communication with the ambient environment. The gas turbine engine may have a core passage including a compressor, a combustion chamber, and a turbine. The core passage may be in selective fluid communication with the inlet. The exhaust may be in fluid communication with the ambient environment and the core passage. The pressurized tank may be located upstream of the core passage. The pressurized tank may contain a cooling fluid. The expansion valve may be in fluid communication with the pressurized tank and the core passage. The pressurized tank may provide cooling fluid to the core passage to cool the gas turbine engine during operation of the secondary engine.

The main purpose of the invention is an air circulation device (1) for a turbomachine (10), comprising an air conveyance circuit (2, 4b, 9, 4a, 3) adapted to bring hot bleed air (A1) from the turbomachine (10) to a part to be heated (38), comprising a first segment fixed in rotation to a rotating part (31, 24) and comprising at least one hot air (A2) conveyance conduit (3, 9), and a hot air passage device (4a, 4b), comprising an annular compartment fixed in rotation to the first segment, characterise in that the annular compartment comprises a heat exchanger in contact with external air, and in that the hot air passage device (4a, 4b) comprises a hot air bypass system to deviate air entering into the device and to make it circulate along the heat exchanger when the temperature of this intake air is above a predetermined threshold.

A film damper for a gas turbine engine includes an annular inner member and an annular outer member located radially outboard of the annular inner member, the annular outer member and the annular inner member defining a damper annulus therebetween. A fluid supply passage delivers a flow of fluid into the damper annulus from the annular outer member, and a backflow prevention device is located at the fluid supply passage to prevent backflow of the flow of fluid from the damper annulus into the fluid supply passage.

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 gas turbine engine having an interdigitated turbine assembly including a first turbine rotor and a second turbine rotor, wherein a total number of stages at the interdigitated turbine assembly is between 3 and 8, and an average stage pressure ratio at the interdigitated turbine assembly is between 1.3 and 1.9. A gear assembly is configured to receive power from the interdigitated turbine assembly, and a fan assembly is configured to receive power from the gear assembly. The interdigitated turbine assembly and the gear assembly are together configured to allow the second turbine rotor to rotate at a second rotational speed greater than a first rotational speed at the first turbine rotor. The fan assembly and the gear assembly are together configured to allow the fan assembly to rotate at a third rotational speed less than the first rotational speed and the second rotational speed. The interdigitated turbine assembly, the gear assembly, and the fan assembly together have a maximum AN.sup.2 at the second turbine rotor between 30 and 90.

A gas turbine engine is disclosed which includes a bypass passage that in some embodiments are capable of being configured to act as a resonance space. The resonance space can be used to attenuate/accentuate/etc a noise produced elsewhere. The bypass passage can be configured in a number of ways to form the resonance space. For example, the space can have any variety of geometries, configurations, etc. In one non-limiting form the resonance space can attenuate a noise forward of the bypass duct. In another non-limiting form the resonance space can attenuate a noise aft of the bypass duct. Any number of variations is possible.