An inlet flow distortion control system employs a plurality of flow control devices forming at least one array integrated into an internal surface of the inlet. The at least one array extends over an azimuthal range relative to a normal flow axis of the inlet and has a plurality of circumferential rows spaced at increasing distance from a highlight of the inlet. A control system is operably connected to the flow control devices and adapted to activate flow control devices in selected subarrays of the array responsive to a predetermined flight condition.

A gas turbine engine with a compressor supplying compressed air. A combustor receives the compressed air and fuel and generates a flow of combusted gas. A turbine receives a core flow of the combusted gas to rotate a turbine rotor. A turbine inlet nozzle directs the combusted gas to the turbine rotor. Vanes are disposed in the turbine inlet nozzle and rotate to vary a flow area through which the core flow passes. The vanes adjust a pressure ratio of the gas turbine engine to compensate for changing operational requirements of the gas turbine engine by rotating to positions matching the changing operational requirements.

A fan assembly includes a fan duct, an inlet fan, and an outlet guide vane assembly. The inlet fan forces 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 adjusts a direction of the fan exit air, and includes a plurality of outlet guide vanes and a plurality of actuation assemblies that control rotation of the outlet guide vanes about a pitch axis. The outlet guide vanes include a leading edge portion and a trailing edge portion rotatably coupled to an axially aft edge of the leading edge portion. The actuation assembly rotates the leading edge portion and the trailing edge portion to minimize losses created by distortions in fan inlet air and created by the leading edge portion redirecting the fan exit air in the first direction.

A fan assembly includes a fan duct, an inlet fan, and an outlet guide vane assembly. The inlet fan forces 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 adjusts a direction of the fan exit air, and includes a plurality of outlet guide vanes and a plurality of actuation assemblies that control rotation of the outlet guide vanes about a pitch axis. The outlet guide vanes include a leading edge portion and a trailing edge portion rotatably coupled to an axially aft edge of the leading edge portion. The actuation assembly rotates the leading edge portion and the trailing edge portion to minimize losses created by distortions in fan inlet air and created by the leading edge portion redirecting the fan exit air in the first direction.

Systems and methods for frequency separation in a gas turbine engine are provided herein. The systems and methods for frequency separation in a gas turbine engine may include determining a hot gas path natural frequency, determining a combustion dynamic frequency, and modifying a compressor discharge temperature to separate the combustion dynamic frequency from the hot gas path natural frequency.

A valve assembly includes an outer housing having a first opening in fluid communication with a first fluid, a second opening in fluid communication with a second fluid, a third opening in fluid communication with a third fluid and a fourth opening in fluid communication with a fourth fluid. The valve assembly includes a piston configured to slide within the outer housing into a first position at which the third opening is blocked from fluid communication with the fourth opening based on a fluid pressure of the first fluid being greater than a fluid pressure of the fourth fluid. The piston is further configured to slide within the outer housing into a second position at which the third opening is in fluid communication with the fourth opening based on the fluid pressure of the second fluid being greater than the fluid pressure of the fourth fluid.

Various methods and systems are provided for a variable geometry ported shroud for a turbocharger. In one example, a compressor system includes a compressor housing defining an air inlet, a shroud, and a bypass passage, a compressor wheel housed in the compressor housing and surrounded by the shroud, only a single port passing through the shroud and fluidically coupled to the bypass passage, and a ring configured to move axially to adjust a restriction of the port.

Instrumented airflow path components configured to determine airflow path distortion in an airflow path of a gas turbine engine (e.g., using for propulsion of an aircraft) are provided. In one embodiment, a gas turbine engine for an aircraft can include a compressor section, a combustion section, and turbine section in series flow. The compressor section, combustion section, and turbine section define at a portion of an engine airflow path for the gas turbine engine. The gas turbine engine further includes one or more members extending at least partially into the engine airflow path of the gas turbine engine and one or more pressure sensor devices at least partially integrated into the one or more members extending at least partially into the engine airflow path. The one or more pressure sensor devices are configured to obtain measurements for determining a distortion condition for the gas turbine engine.

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.

Systems and methods for monitoring aerostructures are provided. In various embodiments, a method for monitoring an aerostructure may include: receiving a signal from a pressure sensor, the pressure sensor located downstream from the aerostructure; performing a time frequency analysis on the signal to calculate a power level over a range of frequencies; monitoring the power level over the range of frequencies; and determining a susceptibility to a flutter condition based on the monitoring the power level.