A compressor section includes a compressor casing that has an upper casing portion coupled to a lower casing portion such that a split-line is defined between the upper casing portion and the lower casing portion. A split-line stator vane assembly includes a first split-line stator vane that has a first shank with a first platform portion and a first mounting portion extends radially outward of the first platform portion. A first airfoil extends radially inward of the platform portion. The first platform portion includes a protrusion that extends circumferentially beyond the split-line. A second split-line stator vane having second shank with a second platform portion and a second mounting portion extends radially outward of the second platform portion. A second airfoil extends radially inward of the second platform portion. The second platform portion includes a recess that extends circumferentially away from the split-line.

In the compressor of a gas turbine engine, variable guide vanes are adjusted by virtue of connections to an actuation ring that can be rotated within a fixed range of degrees. The connections between the guide vanes and the actuation ring can undergo significant torsional stress. Accordingly, an actuation system is disclosed for reducing the torsional stress experienced by the actuation connections.

An article includes a substrate, a ceramic barrier coating, and a layer of networked ceramic nanofibers. The ceramic barrier coating is disposed on the substrate and has a porous columnar microstructure. The layer of networked ceramic nanofibers is disposed on the ceramic barrier layer and seals the pores of the porous columnar microstructure.

There is provided a turbofan engine having: a fan rotatable about an axis within a case; a first acoustic treatment lining a first portion of the case upstream of the fan; and a second acoustic treatment lining a second portion of the case downstream of the fan, the first acoustic treatment having different noise-attenuating characteristics relative to the second acoustic treatment.

An environmental barrier coating, comprising a substrate containing silicon; an environmental barrier layer applied to the substrate; the environmental barrier layer comprising an oxide matrix; an oxidant getter phase interspersed throughout the oxide matrix; and a self-healing phase interspersed throughout the oxide matrix.

A counter-rotating fan, comprising an impeller assembly and an air guide structure. The impeller assembly comprises a first stage impeller and a second stage impeller, of which the rotation directions are opposite. The pressure surfaces of first blades of the first stage impeller are configured to be opposite the suction surfaces of second blades of the second stage impeller, and from the blade root to the blade tip, each of the first blades and the second blades bends toward its own rotation direction. The air guide structure comprises a flow guide cover. The flow guide cover is provided at the center position of the air intake side of the first stage impeller, and the air intake side surface of the flow guide cover at least partially forms a flow guide surface, the flow guide surface extending along the axis of the first stage impeller in the direction away from the counter-rotating fan.

An exhaust diffuser hub disposed at a longitudinal center of an exhaust diffuser is provided. The exhaust diffuser hub includes a hub extension extending from a downstream end thereof in a longitudinal direction of the exhaust diffuser. A transverse cross-sectional area of the hub extension is smaller than a transverse cross-sectional area of the hub.

A gas turbine engine is provided. The gas turbine engine includes a turbomachine having a low speed spool and a high speed spool; a rotor assembly coupled to the low speed spool; an electric machine rotatable with the low speed spool for extracting power from the low speed spool, for adding power to the low speed spool, or both; and an inter-spool clutch positioned between the low speed spool and the high speed spool for selectively coupling the low speed spool to the high speed spool.

A variable-nozzle turbocharger includes a variable-vane mechanism that has an annular nozzle ring supporting an array of rotatable vanes connected to vane arms whose distal ends engage recesses in the radially inner periphery of a rotatable unison ring. Rotation of the unison ring causes the vane arms to pivot about their respective pivot axes at the proximal ends of the arms. The vanes are locked in their fully open position by a locking arrangement that includes locking tongues that extend radially inwardly from the inner periphery of the unison ring and contact the vane arms intermediate their distal and proximal ends.

A gear reduction reduces a speed of a fan rotor relative to a speed of a fan drive turbine. A rigid connection between a fan case and an inner core housing includes a plurality of A-frames connected at a connection point to the fan case. Legs in the A-frames extend away from the connection point in opposed circumferential directions to be connected to a compressor wall of the inner core housing. The rigid connection also includes a plurality of fan exit guide vanes rigidly connected to the fan case. A lateral stiffness ratio of the lateral stiffness of the plurality of fan exit guide vanes and a lateral stiffness of a combination of the plurality of A-frame, the compressor wall, and a fan intermediate case which is forward of the low pressure compressor being greater than or equal to 0.6 and less than or equal to 2.0.