Methods and systems for operating an aircraft engine having a compressor are described. The method comprises determining, based on actual operating parameters of the aircraft engine, a compressor mass flow limit for an aerodynamic stability of the aircraft engine; determining an actual compressor mass flow of the compressor of the aircraft engine, wherein the actual compressor mass flow is based on measured values of the aircraft engine; comparing the actual compressor mass flow to the compressor mass flow limit; and governing operation of the aircraft engine to cause an alternative compressor mass flow when the actual compressor mass flow reaches or is anticipated to reach the compressor mass flow limit.

Methods and systems for controlling a bleed-off valve of a gas turbine engine are described. The method comprises maintaining a first bleed-off valve associated with a first compressor of the gas turbine engine at least partially open upon detection of an unintended engine disturbance causing a drop in pressure of a combustion chamber of the engine; monitoring a rotor acceleration of the first compressor; and controlling closure of the first bleed-off valve when the rotor acceleration of the first compressor reaches a first threshold for a first duration.

There is disclosed a fan assembly including a fan rotor including a hub and fan blades. The fan blades have a leading edge and a trailing edge. A fan stator downstream of the fan rotor relative to a direction of an airflow through the fan assembly. The fan stator includes vanes extending between radially inner ends and radially outer ends. A flow recirculation circuit has an inlet downstream of the vanes of the fan stator and an outlet upstream of the vanes. A recirculation rotor has a plurality of airfoils circumferentially distributed around the axis and located in the flow recirculation circuit. The recirculation rotor is rotatable about the axis within the recirculation circuit. A method of operating the fan assembly is also disclosed.

A turbomachinery stator apparatus includes: a compressor casing including a casing wall defining an arcuate flowpath surface and an opposed backside surface, the flowpath surface defining at least two spaced-apart rotor lands, a stator vane row of stator vanes disposed inside the compressor casing, wherein the casing wall includes a heat shield positioned outboard of the rotor lands immediately upstream or downstream of the stator vane row, and wherein a) the casing wall includes the heat shield and b) the stator vanes form a single monolithic whole.

The gas turbine engine can have a pneumatic actuator; an intake device secured to a gas path wall delimiting the gas path, the intake device having a tubular body protruding from the gas path wall into the gas path and an inlet aperture formed in the tubular body, the inlet aperture spaced-apart from the gas path wall and facing downstream relative a flow orientation of the gas path, the intake device having an internal conduit extending from the inlet aperture, along the tubular body, to an outlet across the gas path wall; and a fluid line fluidly connecting the outlet of the intake device to the pneumatic actuator.

A compressor housing (12) for a turbocharger includes a recirculation cavity (4) formed in a portion of the compressor housing (12). The recirculation cavity (4) is defined by an inner cavity wall (2) and an outer cavity wall (5). In addition, an inlet groove (1) and an outlet (7) are formed in the recirculation cavity (4) for circulating airflow from the compressor housing (12) through the recirculation cavity (4), and at least one recirculation noise obstruction (6) is fixedly secured within the recirculation cavity (4) to disrupt air flow through the cavity and reduce noise in the compressor housing (12).

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.

A hybrid engine includes a gas turbine engine having at least one compressor section and at least one turbine section operably coupled to a shaft. The hybrid engine includes an electric motor configured to augment rotational power of the shaft of the gas turbine engine. A controller is operable to monitor for a transient operation request of the hybrid engine, provide the transient operation request to one or more management systems of the hybrid engine to determine whether one or more faults are detected by the one or more management systems, modify one or more stall margin adjustment parameters of the gas turbine engine based on detecting the one or more faults by the one or more management system, and adjust operation of the hybrid engine based on the one or more stall margin adjustment parameters.

A fan assembly includes a fan duct, an inlet fan, an outlet guide vane assembly, and a control system. The inlet fan includes fan blades adapted to rotate about a central axis to force fan exit air toward an aft end of the fan duct. The outlet guide vane assembly is located in the fan duct downstream of the inlet fan and is configured to adjust a direction of the fan exit air. The outlet guide vane assembly includes a plurality of guide vanes that extend radially relative to the central axis and are configured to rotate to a first vane-pitch angle. The control system is configured to rotate the guide vanes redirect the fan exit air, vary a pressure downstream of the fan inlet, minimize intake flow distortion experienced by the inlet fan, reduce inlet fan vibratory response and/or improve fan operability margins.

A fan assembly includes a fan duct, an inlet fan, and an outlet guide vane assembly. The inlet fan includes blades adapted to force fan exit air toward an aft end of the fan duct. The outlet guide vane assembly is located in the fan duct downstream of the inlet fan and is configured to adjust a direction of the fan exit air received from the blades. The outlet guide vane assembly includes a first plurality of vanes configured to rotate to redirect the fan exit air in a first direction, and a second plurality of vanes located downstream of the first plurality of vanes. The second plurality of vanes are configured to rotate to redirect the fan exit air flowing in the first direction in a second direction to minimize losses created by distortions in fan inlet air and created by the first vanes.