A lubrication system for a device located between an internal shaft and an external shaft of an aircraft turbine, that are free to rotate, concentric and arranged at least partially one around the other, is provided. The lubrication system includes an annular element provided with an external groove and being mounted integral with the external shaft, the external groove being supplied with lubricant from a fixed part of the turbine; and a grooved element mounted integral with the internal shaft, the grooved element having a relief which directs a lubricant in contact with its external surface along a longitudinal direction when the internal shaft is rotating. The external groove is in fluid communication with an external surface of the grooved element through at least two conduits arranged through the external shaft.

A lubrication system for a device located between an internal shaft and an external shaft of an aircraft turbine, that are free to rotate, concentric and arranged at least partially one around the other, is provided. The lubrication system includes an annular element provided with an external groove and being mounted integral with the external shaft, the external groove being supplied with lubricant from a fixed part of the turbine; and a grooved element mounted integral with the internal shaft, the grooved element having a relief which directs a lubricant in contact with its external surface along a longitudinal direction when the internal shaft is rotating. The external groove is in fluid communication with an external surface of the grooved element through at least two conduits arranged through the external shaft.

An axial flow turbomachine (102) for producing thrust to propel an aircraft is shown. The turbomachine has an inner duct (202) and an outer duct (204), both of which are annular and concentric with one another. An inner fan (206) is located in the inner duct, and is configured to produce a primary pressurised flow (P). An outer fan (207) is located in an outer duct, and is configured to produce a secondary pressurised flow (S). The outer fan has a hollow hub (208) through which the inner duct passes. A hub-tip ratio of the outer fan is from 1.6 to 2.2 times a hub-tip ratio of the inner fan.

An axial flow turbomachine (102) for producing thrust to propel an aircraft is shown. The turbomachine has an inner duct (202) and an outer duct (204), both of which are annular and concentric with one another. An inner fan (206) is located in the inner duct, and is configured to produce a primary pressurised flow (P). An outer fan (207) is located in an outer duct, and is configured to produce a secondary pressurised flow (S). The outer fan has a hollow hub (208) through which the inner duct passes. A hub-tip ratio of the outer fan is from 1.6 to 2.2 times a hub-tip ratio of the inner fan.

A gas turbine engine for an aircraft. The gas turbine engine for an aircraft comprising: an engine core comprising an annular gas passage, a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan located upstream of the engine core, the fan comprising a plurality of fan blades; and a power gearbox that receives an input from the core shaft and outputs drive to the fan so as to drive the fan at a lower rotational speed than the core shaft. The engine further has a recirculatory lubricant system which feeds lubricant to and scavenges lubricant from the power gearbox. The engine further has a circumferential row of inlet guide vanes, located downstream of the fan at an air inlet of the annular gas passage. The recirculatory lubricant system includes one or more return passages for lubricant scavenged from the power gearbox, the return passages crossing the annular gas passage through one or more of the inlet guide vanes.

A gas turbine engine for an aircraft. The gas turbine engine for an aircraft comprising: an engine core comprising an annular gas passage, a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan located upstream of the engine core, the fan comprising a plurality of fan blades; and a power gearbox that receives an input from the core shaft and outputs drive to the fan so as to drive the fan at a lower rotational speed than the core shaft. The engine further has a recirculatory lubricant system which feeds lubricant to and scavenges lubricant from the power gearbox. The engine further has a circumferential row of inlet guide vanes, located downstream of the fan at an air inlet of the annular gas passage. The recirculatory lubricant system includes one or more return passages for lubricant scavenged from the power gearbox, the return passages crossing the annular gas passage through one or more of the inlet guide vanes.

Air inlet duct of a turbine engine, in particular an aircraft turbine engine comprising a gas generator, which extends axially between the air inlet and the gas generator and has a first axial wall part and a second wall part which is angularly offset with respect to the first part, which duct is capable of causing, in a shedding region, shedding of the boundary layer formed by an air flow along the wall of the duct; and a device for controlling said shedding of the boundary layer, characterised in that the control device comprises an air-blowing pipe which opens via at least one air-injection opening which is directly upstream of the shedding region, the blowing pipe being connected to an air intake positioned upstream of said air-injection opening or in the shedding region and comprising an air compressor means between the air intake and the air-injection opening.

The invention relates to a turbomachine of an aircraft comprising an outer casing (2) delimiting with an inner hub (3), a flow path (1) of a gas stream in which is disposed a low-pressure turbine configured to rotationally drive a low-pressure shaft; said turbomachine comprising, in the direction of flow of the gas stream, a first propeller (31); and a second propeller (32) downstream of the first propeller, the first propeller (31) being rotationally driven by said low-pressure shaft and the second propeller being rotationally driven by an electric motor (70), the second propeller (32) being further disposed at a distance between 1.5 and 4 cord lengths (LC1) from the first propeller (31) defined between the respective axes of shimming (A31, A32) of each of the first and second propellers.

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 gas turbine engine includes a combustor section arranged between a compressor section and a turbine section. The compressor section includes at least a low pressure compressor and a high pressure compressor. The high pressure compressor is arranged upstream of the combustor section. A fan section has an array of twenty-six or fewer fan blades. The low pressure compressor is downstream from the fan section. An airfoil is arranged in the low pressure compressor and includes pressure and suction sides that extend in a radial direction from a 0% span position to a 100% span position. The airfoil has a relationship between a camber angle and span position that defines a curve with a decreasing camber angle within the range of 80% span to 100% span. The camber angle is less than 20° within the entire range of 40% span to 100% span.