A hybrid electric propulsion system includes a gas turbine engine having a low speed spool and a high speed spool. The low speed spool includes a low pressure compressor and a low pressure turbine, and the high speed spool includes a high pressure compressor and a high pressure turbine. The hybrid electric propulsion system also includes an energy storage system, an electric motor configured to augment rotational power of the high speed spool, and a controller. The controller is operable to detect a start condition of the gas turbine engine, control power delivery from the energy storage system to the electric motor based on detecting the start condition, and provide a compressor stall margin using a power-assist provided by the electric motor to the high speed spool over a targeted speed range during starting of the gas turbine engine.

A hybrid power system for an aircraft comprises a gas turbine connected to a generator for generating electrical power; an electrical storage device configured to output electrical power; a propulsor; a motor operable to drive the propulsor using electrical power from either or both of the generator and the electrical storage device; and a controller. The controller, to meet propulsor power demand, is configured to control an amount of electrical power generated by the generator, and an amount of electrical power outputted by the electrical storage device. In a first control mode coinciding with an increase in the propulsor power demand sufficient to cause a transient excursion of the operating point of a compressor of the gas turbine from a steady state working line, the controller is further configured to temporarily increase the amount of electrical power outputted by the electrical storage device such that the transient excursion is reduced.

Examples described herein provide a computer-implemented method that includes receiving training data indicative of incipient compressor surge for cabin air compressors. The method further includes generating, using the training data, a training spectrogram. The method further includes training, by a processing system, a machine learning model to detect incipient compressor surge events for the cabin air compressors using the spectrogram. The method further includes receiving, at a microcontroller associated with a cabin air compressor, operating data associated with the cabin air compressor. The method further includes generating, at the microcontroller and using the operating data, an operating spectrogram. The method further includes detecting, by the microcontroller associated with the cabin air compressor, an incipient compressor surge event by applying the machine learning model to the operating spectrogram. The method further includes implementing a corrective action to correct the incipient compressor surge event.

Device and methods for guiding bleed air in a turbofan gas turbine engine are disclosed. The devices provided include louvers and baffles that guide bleed air toward a bypass duct of the turbofan engine. The louvers and baffles have a geometric configuration that promotes desirable flow conditions and reduced energy loss.

A sleeve valve includes an inlet port and an outlet port. A sleeve is movable to close flow from the inlet port to the outlet port. The sleeve valve has a sleeve biased to an open position at which it allows flow from the inlet port to the outlet port by a spring. Pressure in a pressure chamber urges the sleeve to a closed position at which it blocks flow from the inlet port to the outlet port. A line pressure conduit communicates the fluid chamber into the pressure chamber. Pressurized air is supplied to the pressure chamber through a selectively closed valve. The selectively closed valve is opened to allow the flow of high pressure air from a pressure source into the pressure chamber to move the sleeve to a closed position. A bleed air system for a gas turbine engine is also disclosed.

An illustrative example embodiment of a compressor includes an inlet defining an intake passage, a plurality of lateral inlet guide vanes in the intake passage, and a plurality of medial inlet guide vanes in the intake passage. The lateral guide vanes are selectively oriented to alter an amount of fluid flow through a first, lateral portion of the intake passage. The medial inlet guide vanes are selectively oriented to alter an amount of fluid flow through a second, medial portion of the intake passage.

An aircraft engine comprising a fan, the fan having a diameter D and including a plurality of fan blades, the fan blades having a sweep metric S.sub.tip, each fan blade having a leading edge, and a forward-most portion on the leading edge of each fan blade being in a first reference plane. The aircraft engine further comprises a nacelle, comprising an intake portion forward of the fan, a forward edge on the intake portion being in a second reference plane, wherein the intake portion has a length L measured along an axis of the aircraft engine between the first reference plane and the second reference plane, the aircraft engine having a cruise design point condition M.sub.rel, wherein M.sub.rel is between 0.4 and 0.93, L/D is between 0.2 and 0.45 and S.sub.tip is from −1 to 0.1.

The present disclosure is directed to turbine engines and systems for active stability control of rotating compression systems utilizing an electric machine operatively coupled thereto. In one exemplary aspect, an electric machine operatively coupled with a compression system, e.g., via a shaft system, is controlled to provide shaft damping for instability fluctuations of the pressurized fluid stream within the compression system. Based on control data indicative of a system state of the compression system, a control parameter of the electric machine is adjusted to control or change an output of the shaft system. Adjusting the shaft system output by adjusting one or more control parameters of the electric machine allows the compression system to dampen instability fluctuations of the fluid stream within the compression system. A method for active stability control of a compression system operatively coupled with an electric machine via a shaft system is also provided.

The present invention relates to an adjustment mechanism (100) for variably adjusting the cross-section of a compressor inlet (22) and further relates to a corresponding compressor (20) including such an adjustment mechanism (100). The adjustment mechanism (100) comprises a plurality of rotatable orifice elements (110) and an actuation ring (120). The actuation ring (120) is mechanically coupled to the plurality of orifice elements 110 such that rotation of the actuation ring 120 causes movement of the orifice elements 110. The movement of the orifice elements (110) thereby adjusts the cross-section of a compressor inlet (22). The adjustment mechanism (100) further comprises a plurality of support members (140) which are arranged axially between the plurality of orifice elements (110) and the actuation ring (120). Additionally, the adjustment mechanism (100) comprises a spring (130), more specific a ring-shaped wave spring. The spring (130) is adapted to axially preload the plurality of orifice elements (110) and the actuation ring (120) when being in a mounted state.

A method and device for detecting conditions conducive to the onset of pumping that can affect a low-pressure compressor of an aircraft turbine engine. The turbine engine including a high-pressure compressor. The method including measuring a speed variation of the aircraft and measuring a speed variation of the high-pressure compressor. The method including a preliminary step of measuring an altitude of the aircraft. The conditions conducive to the onset of pumping being detected when the following conditions are jointly obtained: (a) the speed variation measured over a predetermined time interval corresponds to an acceleration greater than a first positive threshold, (b) the measured speed variation corresponds to a deceleration less than a second negative threshold, and (c) the altitude is greater than a third predetermined threshold.