The present disclosure defines a morphing airfoil having a dynamic flexible anisotropic skin system that is capable of carrying high level aerodynamic (or fluid) pressure loads over a structural surface. The structural surface can morph and bend in response to control inputs to change a lift force without separate movable control surfaces. The anisotropic skin is attached to underlying active and compliant structures. A control system causes the underlying support structure to move to a desired location which in turn causes the skin to bend and/or flex without exceeding a stress threshold and thus vary the lift profile along a span of the airfoil.

A gas turbine engine may include a high speed spool, a low speed spool, a first epicyclic gear system, and a second epicyclic gear system. Generally, the high speed spool mechanically connects a high pressure turbine to a high pressure compressor, and the low speed spool mechanically connects a low pressure turbine to at least one of a fan and a prop via the first epicyclic gear system and to a low pressure compressor via the second epicyclic gear system, according to various embodiments. The first epicyclic gear system and the second epicyclic gear system may include a common sun gear shaft.

An ejector comprises a primary nozzle having an annular wall forming part of an outer boundary of an exhaust portion of a primary flow path of a gas turbine engine. The annular wall has a downstream end defining a plurality of circumferentially distributed lobes. The ejector further comprises a secondary nozzle having an annular wall disposed about the primary nozzle, the primary nozzle and the secondary nozzle defining a secondary flow passage therebetween for channeling a secondary flow. The secondary nozzle defines a mixing zone downstream of an exit of the primary nozzle. A flow guide ring is mounted to the primary nozzle lobes. The ring has an aerodynamic surface extending from a leading edge to a trailing edge respectively disposed upstream and downstream of the exit of the primary nozzle. The aerodynamic surface of the ring is oriented to guide the high velocity primary flow into the mixing zone.

Herein provided are methods and systems for a method for controlling autothrottle of an engine. A digital power request is obtained from an autothrottle controller, the digital power request based on an autothrottle input to the autothrottle controller. A manual input mode for the engine is terminated, the manual input mode based on a second power request obtained from a manual input associated with the engine. An autothrottle mode for the engine is engaged to control the engine based on the digital power request.

A gas turbine engine, has: a case extending circumferentially around a central axis of the gas turbine engine; a boss protruding from the case away from the central axis, the boss defining an internal passage; a tubular member received within the internal passage of the boss and secured to the boss; an annular gap extending all around the tubular member and located between the tubular member and the boss; and a fitting hydraulically connecting a fluid source to the tubular member, the fitting having a portion received within the tubular member and encircled by both of the annular gap and the tubular member, the fitting sealingly engaged to the tubular member.

Methods and systems for operating a gas turbine engine are described. The method comprises obtaining, at a control system associated with the gas turbine engine, a measured engine core speed and an actual power demand for the gas turbine engine during operation thereof, determining an expected engine core speed based on the actual power demand from a predicted relationship between engine core speed and engine output power, comparing the measured engine core speed to the expected engine core speed, detecting a torque-related fault when the measured engine core speed differs from the expected engine core speed by more than a threshold; and accommodating the torque-related fault when detected.

A turbomachinery engine includes an unducted rotor assembly, a low-pressure turbine, a low-pressure shaft, a gearbox, and an engine correlation parameter. The unducted rotor assembly includes a plurality of rotor blades arranged in a single row and defining a blade diameter. The gearbox includes an input, an output, and a gear ratio. The input of the gearbox is coupled to the low-pressure shaft (which is coupled to the LPT), and the output of the gearbox is coupled to the unducted rotor assembly. The engine correlation parameter is greater than 0.17 and less than 0.83. The engine correlation parameter equals D/N/GR, where D is the blade tip diameter measured in feet, N is the stage count of the low-pressure turbine, and GR is the gear ratio of the gearbox. The unducted propulsor assembly optionally includes a disk loading within a range of 60-180 HP/ft.sup.2 at a takeoff flight condition.

An unducted thrust producing system has a rotating element with an axis of rotation and a stationary element. The rotating element includes a plurality of blades, each having a blade root proximal to the axis, a blade tip remote from the axis, and a blade span measured between the blade root and the blade tip. The rotating element has a load distribution such that at any location between the blade root and 30% span the value of ΔRCu in the air stream is greater than or equal to 60% of the peak ΔRCu in the air stream.

A gas turbine engine has a housing exposed to a high temperature environment. The housing has a circumferential wall extending around the engine centerline and circumscribing an oil cavity. The wall has a sealing interface at an inner diameter thereof, the sealing interface having a central axis offset from the engine centerline. A boss is formed on the wall on the offset side relative to the engine centerline and a probe is mounted to the boss. The probe projects into the oil cavity. The oil in the oil cavity thermally shields the probe from the high temperature environment.

A gas turbine engine, has: a case extending circumferentially around a central axis of the gas turbine engine; a boss protruding from the case away from the central axis, the boss defining an internal passage; a tubular member received within the internal passage of the boss and secured to the boss; an annular gap extending all around the tubular member and located between the tubular member and the boss; and a fitting hydraulically connecting a fluid source to the tubular member, the fitting having a portion received within the tubular member and encircled by both of the annular gap and the tubular member, the fitting sealingly engaged to the tubular member.