A geared turbofan engine with a sun shaft driving a sun gear of planetary gearbox. The sun shaft having a front section proximal to the gearbox and a rear section distal from the gearbox. The outer diameter of the front section of the sun shaft is smaller than the outer diameter of the rear section of the sun shaft. The front section of the sun shaft having between two and four undulant sections, wherein each undulant section having at least one axial part extending in axial direction of the sun shaft and two diaphragm parts on either side of the at least one axial part extending in radial direction outward, the at least one axial part of the undulant section having an inner diameter smaller than the outer diameter of the front section of the sun shaft.

A method of manufacturing a gas turbine engine including designing a row of vanes provided upstream of an asymmetric gas flow volume. The method includes two dimensionally optimizing camberline and stagger angle of each vane, including using orthogonal polynomials to modify the camberline and stagger angle of each vane.

A coupling device for rotably coupling a shaft with a gearbox in a geared turbo fan aircraft engine, wherein the coupling device includes a connection to the shaft at a first end and a connection to the gearbox at a second end, the first and the second ends being axially separated and at least one curved shape between the first end and the second end extending from the gearbox radially inwards to the shaft and the at least one curved shape including at least one cross-section in the axial direction of the engine with a logarithmic profile or a power profile.

A turbine vane of a turbine engine such as a turbojet. The vane includes a base supporting a blade that extends in a spanwise direction and ends in an apex. The blade includes a pressure-side wall and a suction-side wall, each ending at an end edge at the apex of the blade. The blade includes, at the apex thereof, a closed wall extending from the pressure-side wall to the suction-side wall so as to define, with the end edges, a tub shape. The pressure-side wall is curved inward so as to deviate from the spanwise direction in the region of the blade apex preceding the tub, between the base and the pressure-side end edge.

A geared turbofan engine with a sun shaft driving a sun gear of planetary gearbox. The sun shaft having a front section proximal to the gearbox and a rear section distal from the gearbox. The outer diameter of the front section of the sun shaft is smaller than the outer diameter of the rear section of the sun shaft. The front section of the sun shaft having between two and four undulant sections, wherein each undulant section having at least one axial part extending in axial direction of the sun shaft and two diaphragm parts on either side of the at least one axial part extending in radial direction outward, the at least one axial part of the undulant section having an inner diameter smaller than the outer diameter of the front section of the sun shaft.

A method of manufacturing a gas turbine engine including designing a row of vanes provided upstream of an asymmetric gas flow volume. The method includes two dimensionally optimising camberline and stagger angle of each vane, including using orthogonal polynomials to modify the camberline and stagger angle of each vane.

A turbine engine includes an engine core extending along an engine centerline and includes a compressor section, a combustor, and a turbine section in serial flow arrangement. A set of blades are circumferentially arranged in the turbine section and the compressor section. A set of dovetails mounts the set of blades to a disk, rotated about the engine centerline. Each dovetail can include a set of lobes defining complementary recesses, collectively defining a neck for mounting to the disk.

A turbine engine includes an engine core extending along an engine centerline and includes a compressor section, a combustor, and a turbine section in serial flow arrangement. A set of blades are circumferentially arranged in the turbine section and the compressor section. A set of dovetails mounts the set of blades to a disk, rotated about the engine centerline. Each dovetail can include a first upper lobe and a first lower lobe defining a first intervening recess, and a second upper lobe and a second lower lobe defining a second intervening recess, collectively defining a neck for mounting to the disk.