An electronic control system (35) for a turbopropeller (2) having a gas turbine engine (20) and a propeller assembly (3) coupled to the gas turbine engine (20), the control system (35) having: a propeller control stage (35a), implementing a closed loop control for controlling operation of the propeller assembly (3) based on a scheduled propeller speed reference (Nr.sub.ref) and a propeller speed measure (Nr); a gas turbine control stage (35b), implementing a closed loop control for controlling operation of the gas turbine engine (20) based on a scheduled reference (Ngdot.sub.ref) and at least a feedback quantity. The control system (35) further envisages an auxiliary control stage (35c), coupling the propeller control stage (35a) and the gas turbine control stage (35b) and determining a limitation of the operation of the gas turbine engine (20), if a propeller speed overshoot is detected, with respect to the propeller speed reference (Nr.sub.ref).

Methods and apparatus to reduce deflection of an airfoil are disclosed. An example apparatus disclosed herein includes a plate including an aperture, the airfoil disposed in the aperture, and a damper operatively coupled between the plate and a hub of the airfoil, the damper to transform flexural deflection of the airfoil to radial deflection of the plate.

The invention concerns a power transmission system of a turbomachine, comprising: a speed reducer (12) comprising a sun gear (15) rotationally secured to a power shaft (5) with a longitudinal axis, an outer ring gear (18) rotating a rotor shaft along the longitudinal axis, and a planet carrier (17), and a device (40) for recovering oil ejected by centrifugal effect and comprising an annular gutter (41) for recovering the ejected oil, the gutter being attached to a fixed annular housing (26) and having a recovery chamber (42) and a first wall portion (43) disposed at least partially facing oil ejection means (30) of the speed reducer for directing the oil to the recovery chamber.

According to the invention, the recovery chamber is provided with an inlet opening (45) directed radially outwardly and defined in a plane radially lower than a plane where an outlet port (33) of the ejection means is defined.

An assembly for an aircraft turbine machine including a receiver for a pair of open rotor contra-rotating propellers, the assembly including a duct, ancillaries routed inside the duct, an attachment case, attachment device of the duct on an annular installation portion of the case. The attachment device in an assembled configuration include a split ring fitted with internal projections housed inside orifices in the duct; a radial loading surface of the ring made on the portion the surface being tapered and narrowing along a first axial direction, and being in contact with a peripheral surface of the complementary shaped tapered split ring; device of axially loading the ring along the first direction, the device being blocked in the axial direction on the portion.

A turbomachine engine according to aspects of the present disclosure is provided. The engine includes a fan assembly including a plurality of fan blades, and a core engine surrounded by an outer casing. The core engine includes a power output component operably connected to the fan assembly, a first input power source and a second input power source. The first input power source is counter-rotatable relative to the second input power source. The core engine includes a gear assembly operably connected to the power output component and configured to receive power from the first input power source and the second input power source.

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.

An unducted thrust producing system is provided that can include a rotating element having an axis of rotation about a central longitudinal axis and comprising a plurality of blades attached to a spinner; a stationary element positioned aft of the rotating element; and an inlet positioned between the rotating element and the stationary element such that the inlet passes radially inward of the stationary element. The rotating element defines an annular valley positioned between a first annular crown and a second annular crown, and the inlet defines an open area positioned aft of the second annular crown.

An unducted thrust producing system, includes a rotating element, a stationary element. An inlet may be located forward or aft of the rotating element and the stationary element. An exhaust may be located forward, aft, or between the rotating element and the stationary element.

A turbomachine of an aircraft comprising an outer casing delimiting with an inner hub, a flow path 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; and a second propeller downstream of the first propeller, the first propeller being rotationally driven by said low-pressure shaft and the second propeller being rotationally driven by an electric motor, the second propeller being further disposed at a distance between 1.5 and 4 cord lengths from the first propeller defined between the respective axes of shimming of each of the first and second propellers.

An engine assembly defining an axial direction (A) and including a gearbox, an engine core including at least one rotor, and a flexible coupling shaft having a first end and a second end along the axial direction (A). The first end of the flexible coupling shaft is connected to the engine core and the second end of the flexible coupling shaft is connected to the gearbox. A damper system is positioned at the second end of the flexible coupling shaft. The damper system is configured to reduce vibrations to the flexible coupling shaft during operation of the engine assembly.