A curved contour of the lateral surface of a blade arrangement includes in at least one meridian section on mutually opposite sides of a blade airfoil an intersection point that is closer to the blade airfoil front edge, and an intersection point that is closer to the blade airfoil rear edge, and a best-fit line of least square distances from the curved contour. The curved contour includes first and/or the second contour section which meet specified conditions.

An airfoil for a gas turbine engine according to an example of the present disclosure includes, among other things, an airfoil section extending between a leading edge and a trailing edge in a chordwise direction and extending between a tip portion and a root section in a spanwise direction. The airfoil section defines pressure and suction sides separated in a thickness direction. A sheath extends in the spanwise direction along at least one of the pressure and suction sides of the airfoil section. A tip cap extends in the chordwise direction along the at least one of the pressure and suction sides. The sheath includes a first set of interface members. The tip cap includes a second set of interface members interleaved with the first set of interface members to establish at least one joint along an external surface of the at least one of the pressure and suction sides. A method of assembly for an airfoil is also disclosed.

A vacuum pump includes a plurality of exhaust stages provided between an inlet port and an exhaust port so as to function as means for exhausting gas molecules, and a number of blades provided between the inlet port and an uppermost exhaust stage of the plurality of exhaust stages so as to rotate together with a rotary blade that constitutes the uppermost exhaust stage as a particle transport stage for transporting particles in an exhaust direction of the gas molecules, the number being smaller than the number of rotary blades that constitutes the uppermost exhaust stage.

A centrifugal compressor impeller is disclosed for a charging device of an internal combustion engine. The impeller comprises a hub, a number of full blades arranged on the hub and being spaced in a circumferential direction of the impeller, and one splitter blade arranged between a pressure side of a first full blade and a suction side of a second full blade of the number of full blades. A leading edge of the splitter blade is arranged closer to the pressure side of the first full blade than the suction side of the second full blade. The present disclosure further relates to a charging device, an internal combustion engine, and a vehicle.

A gas turbine engine comprises a fan mounted to rotate about a main longitudinal axis; an engine core, comprising in axial flow series a compressor, a combustor, and a turbine coupled to the compressor through a shaft; a reduction gearbox that receives an input from the shaft and outputs drive to the fan so as to drive the fan at a lower rotational speed than the shaft; wherein the compressor comprises a first stage at an inlet and a second stage, downstream of the first stage, comprising respectively a first rotor with a row of first blades and a second rotor with a row of second blades, the first and second blades comprising respective leading edges, trailing edges and tips, and wherein the ratio of a maximum leading edge radius of the first blades to a maximum leading edge radius of the second blades is greater than 2.8.

Each of a plurality of blades of a turbofan includes a thick wall portion, a thin wall portion and a stepped portion. The stepped portion is formed between the thick wall portion and the thin wall portion. A plate thickness of the stepped portion is progressively decreased toward a positive pressure surface of the blade in a direction that is directed from the thick wall portion toward the thin wall portion. In the blade, a first curved surface forms a negative pressure surface of the thick wall portion, and a second curved surface forms a negative pressure surface of the thin wall portion while the second curved surface is located on a side of the first curved surface where the positive pressure surface of the blade is placed, and a negative pressure surface of the stepped portion connects between the first curved surface and the second curved surface.

Airfoils and methods of cooling an airfoil are provided. The airfoil may comprise a spar; a coversheet on the spar; and a dual feed circuit between the spar and the coversheet. The dual feed circuit may include a first dam, a second dam spaced apart from the first dam along the chord axis of the spar, a first inlet disposed adjacent to the first dam, a second inlet disposed adjacent to the second dam, a circuit outlet disposed between the first inlet and the second inlet, and a plurality of diamond and/or hexagonal pedestals disposed on an outer surface of the spar. The diamond and/or hexagonal pedestals may form a plurality of cooling channels between the first inlet, the second inlet, and the circuit outlet. There may be no other circuit inlets are located between the first inlet and the second inlet.

A method of debonding a first layer from a second layer, wherein the first layer is bonded to the second layer by an adhesive located between the first and second layers. The method includes inserting a blade of a cleaving tool between the first and second layers, and exerting a controlled force on the cleaving tool to move the cleaving tool so as to de-bond the first and second layers in a region. The force exerted is controlled to match a de-bonding force calculated for the region, and such that the movement of the cleaving tool stops when the calculated force is less than a force required to move the cleaving tool, and continues when the calculated force is higher than or equal to the force required to move the cleaving tool.

A fan blade (1) has a front leading edge (2) and a rear trailing edge (3). The fan blade (1) has a leading edge (4), at least some portions, that are undulated. The edge forms a wave (W) with a specific three-dimensional waveform.

A blade for a rotor of a gas turbine has: a root, a platform having a lower surface and an upper surface opposite to the lower surface, a hollow aerofoil, an inner cooling passage inside the hollow aerofoil for channelling a first cooling medium to a first plurality of outlet cooling holes on an external surface of the hollow aerofoil, a channel, separated from the first cooling circuit, extending through the platform for channelling a second cooling medium from at least one opening of the channel to a second plurality of outlet cooling holes provided on the upper surface of the platform. The at least one opening of the channel is provided on the lower surface of the platform in order to receive in operation the second cooling medium from an inner cavity of the rotor.