A system and method for detecting inlet temperature distortion of an engine are described. The method comprises obtaining an outside air temperature from at least one first sensor, obtaining an inlet temperature of the engine from at least one second sensor, determining an inlet temperature distortion based on a difference between the outside air temperature and the inlet temperature, comparing the inlet temperature distortion to a threshold, and issuing an alert when the inlet temperature distortion exceeds the threshold.

A rotary component for a gas turbine engine defining a central axis extending along an axial direction, a radial direction extending perpendicular to the axial direction, and a circumferential direction perpendicular to both the central axis and the radial direction. The rotary component includes a plurality of rotor blades operably coupled to a rotating shaft extending along the central axis and an outer casing arranged exterior to the plurality of rotor blades in the radial direction and defining an annular gap between a tip of each of the plurality of rotor blades and the outer casing. The outer casing includes a plurality of features on an interior surface of the outer casing. A first feature of the feature(s) defines a first casing thickness, and a second feature positioned at least partially circumferentially or axially from the first feature defines a second casing thickness different than the first casing thickness.

A gas turbine engine includes a shroud with an abradable section and a non-abradable section that cooperatively define a shroud surface. The gas turbine engine also includes a rotor that is supported for rotation within the shroud to generate an aft axial fluid flow. The rotor includes a blade with a blade tip that is crowned and that opposes the abradable section and the non-abradable section of the shroud surface. A crown area of the blade tip opposes the abradable section. A casing treatment feature is provided in the non-abradable section of the shroud to oppose the blade tip of the rotor.

Methods and apparatus for reducing flow distortion at engine fans of nacelles are disclosed. An example apparatus for reducing flow distortion at an engine fan of a nacelle includes a plurality of nozzles radially spaced about an inner wall of the nacelle. In some examples, respective ones of the nozzles are positioned to eject corresponding respective jets of fluid adjacent the inner wall in a downstream direction toward the engine fan. The example apparatus further includes a controller to selectively activate the respective ones of the nozzles according to a time-based sequence. In some examples, the time-based sequence corresponds to a directional sequence that moves in an arcuate direction along a circumference of the inner wall.

Methods and apparatus for reducing flow distortion at engine fans of nacelles are disclosed. An example apparatus for reducing flow distortion at an engine fan of a nacelle includes a plurality of nozzles radially spaced about an inner wall of the nacelle. In some examples, respective ones of the nozzles are positioned to eject corresponding respective jets of fluid adjacent the inner wall in a downstream direction toward the engine fan. The example apparatus further includes a controller to selectively activate the respective ones of the nozzles according to a time-based sequence. In some examples, the time-based sequence corresponds to a directional sequence that moves in an arcuate direction along a circumference of the inner wall.

A gas turbine engine assembly according to an exemplary embodiment of this disclosure includes, among other possible things, a plurality of fan blades rotatable about a fan rotation axis; a fan nacelle at least partially surrounding the plurality of fan blades, the fan nacelle defining an inlet; at least one sensor positioned forward of the fan nacelle, the at least one sensor generating a signal indicative of an airflow condition entering the inlet; an effector that is actuatable to accommodate distortions in inlet airflow; and a controller receiving the signal from the at least one sensor and determining an inlet distortion condition corresponding to the signal indicative of an airflow condition and actuating the effector based on the identified inlet distortion condition.

A method to predict an onset of flow separation from a surface of an inner barrel of a nacelle is disclosed. In various embodiments, the method includes determining a static pressure distribution about the inner barrel surface of the nacelle; determining a mean static pressure value and a minimum static pressure value using the static pressure distribution; determining a separation indicator value using the mean static pressure value and the minimum static pressure value; and comparing the separation indicator value against a separation threshold value.

A method of maintaining rotor tip clearance and compressor operational line during a transient operation of a gas turbine engine is disclosed. In various embodiments, the method includes applying high spool auxiliary power to a high speed spool for a first time period, applying low spool auxiliary power to a low speed spool for a second time period, sensing one or more operational parameters of the gas turbine engine during the transient operation, and ceasing application of power to the high speed spool, based on the one or more operational parameters.

A system is provided for an aircraft. This aircraft system includes a gas turbine engine and a sensor system. The gas turbine engine includes an inlet and a compressor section. A flowpath projects radially inward into the gas turbine engine from the inlet and extends through the compressor section. The sensor system includes a plurality of static pressure sensors at least partially within the flowpath. The sensor system is configured to determine a total pressure characteristic within the flowpath using the plurality of static pressure sensors.

A turbomachine for an aircraft is provided. The turbomachine includes a plurality of radially-extending blades and an annular endwall opposite the radially-extending blades. The endwall includes an endwall treatment recessed into the endwall. The endwall treatment is characterized by a casing treatment volume compressibility factor (CTVCF), and a casing treatment normalized volume (CTNV), and a blade tip Mach number (Mtip).