An acoustic liner for a gas turbine engine includes an acoustic panel that is curved about a central axis. The acoustic panel includes a support backing, a face sheet, and a cellular structure disposed between the support backing and the face sheet. The face sheet has elongated slots that extend along respective slot centerlines in the plane of the face sheet. The slot centerlines are sloped at oblique angles to the central axis.

A structure for damping at a fluid manifold assembly for an engine is generally provided. The fluid manifold assembly includes a first walled conduit defining a first fluid passage therewithin. A flow of fluid defining a first frequency is permitted through the first fluid passage. A second walled conduit includes a pair of first portions each coupled to the first walled conduit. A second portion is coupled to the pair of first portions. A second fluid passage is defined through the first portion and the second portion in fluid communication with the first fluid passage. The flow of fluid is permitted through the second fluid passage at a second frequency approximately 180 degrees out of phase from the first frequency.

A noise attenuation panel for a structure within a propulsion system includes a first plurality of unit cells; and a second plurality of unit cells, the second plurality of unit cells merged within the first plurality of unit cells, the first plurality of unit cells including a first periodic structure having a first unit cell, a second unit cell, a third unit cell and a fourth unit cell, each of the first unit cell, the second unit cell, the third unit cell and the fourth unit cell including a central body interconnected via a plurality of lateral tubes extending from the central body, the first periodic structure forming a first lateral layer of unit cells.

Various examples of an active combustion control valve, combustion systems, and method of controlling the flow of liquid fluid in a gas combustion system are described. In one aspect of the present invention, an active combustion control valve includes a core valve housing, an actuator, a valve seat in communication with the actuator, and a passageway in fluid communication with the core valve housing and the valve seat. The control valve is responsive to change in voltage applied to the actuator and is capable of a first condition permitting a first fluid flow through the passageway and a second condition permitting a second fluid flow through the passageway, the first fluid flow being different than the second fluid flow. The combustion control valve is small, robust, responsive and self-cooling to operate in severe thermal environment.

A gas turbine engine may include a combustion section having a fuel nozzle, a swirler, and a ferrule configured to mount and center the fuel nozzle with the swirler. The combustion section may further include a damper on a cold side of the combustion section. The damper may have an acoustic cavity, a damper neck, and a cavity feed hole. The damper may operate as Helmholtz cavity to absorb a hydrodynamic or acoustic instability present in a region within the swirler.

An aeroderivative gas turbine including an air intake plenum; a compressor with a compressor air intake in fluid communication with the air intake plenum; a combustor; a high pressure turbine; a power turbine. A forced air-stream generator is arranged in fluid communication with the air intake plenum. A shutter arrangement is provided in a combustion-air flow path, arranged and controlled to close the combustion-air flow path for pressurizing said air intake plenum by means of the forced air-stream generator to a pressure sufficient to cause pressurized air to flow through the aeroderivative air turbine.

A propulsion system including: a fuel cell assembly comprising a fuel cell, the fuel cell defining an outlet positioned to remove output products from the fuel cell and a fuel cell assembly operating condition; a turbomachine comprising a compressor section, a combustion section, and a turbine section arranged in serial flow order, the combustion section configured to receive a flow of aviation fuel from the aircraft fuel supply and further configured to receive the output products from the fuel cell; and a controller comprising memory and one or more processors, the memory storing instructions that when executed by the one or more processors cause the propulsion system to perform operations including: delivering the output products from the fuel cell to the combustion section to mitigate combustion dynamics within the combustion section.

A gas turbine engine includes a combustion section, the combustion section including a plurality of fuel nozzles. A fuel delivery system for the gas turbine engine includes a feed tube and a fuel manifold fluidly connected to the feed tube for receiving fuel from the feed tube. The fuel delivery system also includes a pigtail fuel line fluidly connected to the fuel manifold and configured to fluidly connect to a fuel nozzle of the plurality of fuel nozzles when the fuel delivery system is installed in the gas turbine engine. In order to reduce an amount of hydraulic instability of a fuel flow through the fuel delivery system, at least one of the fuel manifold or the pigtail fuel line includes a means for damping a hydraulic instability within the fuel delivery system.

A rotor shaft cap for a gas turbine has a disk-shaped body defining a first axial face, a second axial face, and an outer radial face. The disk-shaped body has a first annular jaw provided on the first axial face. The first annular jaw includes a plurality of teeth projecting from the first axial face. A plurality of apertures are defined by the disk-shaped body, each aperture of the plurality of apertures extends through the disk-shaped body along an axial direction.

A multivariable fuel control and estimator (MFCE) of a gas turbine engine for preventing combustor blowout is provided. The MFCE includes a first input port that receives controller requests and provide system usage commands, a second input port that receives measured disturbance values, a third input that receives system and component limits, a fourth input port that receives sensed parameters, a fuel system model of the fuel system of the gas turbine engine and an engine model of the engine system that includes the combustor of the gas turbine engine, a processor that generates a control signal for controlling the fuel valve and generates a control signal for controlling the actuator using the fuel system and engine model based on the controller requests, the measured disturbance values, the system and component limits, and the sensed parameters, and an output port that transmits the control signals to the fuel system.