Abstract: An acoustic core may include an array of resonant cells configured as a plurality of resonant cell groups. The resonant cell groups may include a plurality of resonant cells configured as a partitioned resonant cell that include a converging resonant cell and a diverging resonant cell. The converging resonant cell and the diverging resonant cell may be defined by a plurality of cell walls integrally formed with one another and a partition integrally formed with the plurality of cell walls. The partition may at least partially delimit the converging resonant cell from the diverging resonant cell. The converging resonant cell may define an upper resonant space delimited by the partition and a top face of the array of resonant cells. The diverging resonant cell may define a lower resonant space delimited by the partition and a bottom face of the array of resonant cells.

Abstract: An airfoil is provided defining a spanwise direction, a chordwise direction, a root end, a tip end, a leading edge end, and a trailing edge end. The airfoil includes: a leading edge extending from the leading edge end; a body extending along the spanwise direction between the root end and the tip end, the body including a plurality of cavity walls defining a plurality of cavities, each of the plurality of cavities having an inlet located at the leading edge; and a porous face sheet positioned on at least one inlet of the plurality of cavities.

Abstract: A rotary component for a gas turbine engine 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 a radial direction of the gas turbine engine. The outer casing defines a gap between a blade tip of each of the plurality of rotor blades and the outer casing. The outer casing includes a plurality of features formed into an interior surface thereof. Each of the plurality of features includes one or more design parameters that are perturbed about a mean design parameter for stall performance so as to provide a circumferential variation in wake strengths associated with the plurality of rotor blades, thereby reducing operational noise of the gas turbine engine.

Abstract: A rotary component includes a plurality of rotor blades operably coupled to a rotating shaft extending along a central axis of the rotary component and an outer casing arranged exterior to the plurality of rotor blades in a radial direction of the rotary component. The outer casing defines a gap between a blade tip of each of the plurality of rotor blades and the outer casing. The outer casing includes a plurality of features formed into an interior surface thereof. Further, at least one feature of the plurality of features is a slot having an acoustic liner feature integrated therein to reduce operational noise of the rotary component.

Abstract: Provided is a clutch assembly, a SSSV, and a method for operating an SSSV. The clutch assembly, in one aspect, includes an output coupler housing, an input shaft, and an electromagnet coupled to the input shaft. In at least one aspect, the electromagnet is configured to axially translate the output coupler housing from a de-coupled state to a coupled state when the electromagnet is energized. The clutch assembly, in one aspect, further includes one or more grooves located in one of an outer surface of the input shaft or an inner surface of the central opening, and one or more engagement members located in the other of the inner surface of the central opening or the outer surface of the input shaft.

Abstract: An exhaust nozzle for a gas turbine engine. The exhaust nozzle comprises a nozzle body having an upstream end axially spaced from a downstream end with respect to an axial centerline of the nozzle body, and a plurality of chevrons circumferentially spaced apart and extending downstream from the downstream end. Each chevron includes an inner wall radially spaced from an outer wall, a root and a tip axially spaced from the root. At least one chevron of the plurality of chevrons includes a first segment extending axially downstream from the root, a second segment extending axially downstream from the first segment, and a third segment extending axially downstream from the second segment to the tip. The inner wall extends along the first segment, the second segment, and third the segment. The first segment is distinguishable from the second segment and the second segment is distinguishable from the third segment.

Abstract: A cascade thrust reverser assembly is provided for a turbofan engine. The turbofan engine includes a nacelle assembly defining a bypass passage, and the cascade thrust reverser assembly includes at least one cascade assembly configured to be at least partially enclosed by the nacelle assembly. The cascade assembly may further include a plurality of cascade segments and an actuation assembly operably connected to the plurality of cascade segments, wherein the actuation assembly is configured to increase an axial extent of the cascade assembly and rotate the plurality of cascade segments.

Abstract: An aircraft engine includes a low pressure spool, a high pressure spool, and an alternative power source. The alternative power source is configured to add power to the high pressure spool. A controller is configured to determine a noise sensitive condition; and control, in response to determining the noise sensitive condition, the alternative power source to add power to the high pressure spool.

Abstract: An aerodynamic device defining a thickness direction is provided. The aerodynamic device configured to produce lift or thrust or configured to be a part of an aerodynamic system that produces lift or thrust. The aerodynamic device includes a cowl assembly that defines at least in part an airflow stream. The cowl assembly includes a first cowl and a second cowl moveable relative to the first cowl. The first cowl includes a plurality of first cowl indentations at an end of the first cowl. The second cowl defines an outer surface along the thickness direction and an inner surface along the radial direction. The second cowl includes a plurality of second cowl indentations complementary in shape to the plurality of first cowl indentations. The plurality of second cowl indentations are positioned locally on the outer surface of the second cowl or locally on the inner surface of the second cowl.

Abstract: A cascade thrust reverser assembly for a gas turbine engine includes a nacelle assembly defining a bypass passage. The cascade thrust reverser assembly includes a cascade assembly configured to be at least partially enclosed by the nacelle assembly, the cascade assembly comprising one or more cascade members, the one or more cascade members movable between a stowed configuration wherein the one or more cascade members define a first radial extent and a deployed configuration wherein the one or more cascade members define a second radial extent, wherein the one or more cascade members form a cascade segment in the deployed configuration, and wherein the second radial extent is greater than the first radial extent.

Abstract: An airfoil is provided defining a spanwise direction, a chordwise direction, a root end, a tip end, a leading edge end, and a trailing edge end. The airfoil includes: a leading edge extending from the leading edge end; a body extending along the spanwise direction between the root end and the tip end, the body including a plurality of cavity walls defining a plurality of cavities, each of the plurality of cavities having an inlet located at the leading edge; and a porous face sheet positioned on at least one inlet of the plurality of cavities.

Abstract: A turbofan engine is provided. The turbofan engine includes a fan comprising a plurality of fan blades; and a nacelle that circumferentially surrounds the fan, the nacelle comprising an annular wall having an exterior surface and an interior surface, the exterior surface comprising a first exterior portion, and the interior surface comprising a first interior portion, wherein a first exterior portion is formed of a first structure defining an exterior surface porosity, and wherein a first interior portion is formed of a second structure defining an interior surface porosity.

Abstract: Electronic documents may be large and have numerous pages, sections and areas of information that are useful to some individuals and not others. It is common for large documents to include some information that is intended for only certain recipients and other information that is intended for other recipients. One example may provide receiving a document including a number of pages, identifying a number of extraction attributes corresponding to various users identified in the document, querying the document for the extraction attributes, and creating a number of new documents corresponding to the extraction attributes.

Abstract: A turbofan engine may include a variable pitch fan rotatable about an axis and operable in a forward thrust mode by generating flow opposite a direction of travel and in a reverse thrust mode by generating flow in the direction of travel. In reverse thrust mode, a nacelle assembly defines an intermediate opening disposed aft of the variable pitch fan. A flow guide assembly is configured to guide a first fluid flow opposite the direction of travel within a bypass passage from a forward opening to an aft opening of the nacelle assembly in forward thrust mode, and to redirect a second fluid flow from outside the bypass passage opposite the direction of travel to inside the bypass passage in the direction of travel through the intermediate opening in reverse thrust mode. One or more flow channels are defined for generating at least one fluidic injection pressurized by a core.

Abstract: A gas turbine engine defining an axial direction and a radial direction, the gas turbine engine including: a turbomachine; a fan rotatable by the turbomachine, the fan including a plurality of fan blades; a plurality of outlet guide vanes located downstream of the plurality of fan blades of the fan; a casing surrounding the plurality of fan blades or surrounding at least in part the turbomachine, the casing defining an opening at a location upstream of the plurality of outlet guide vanes; and a compressed airflow injection assembly positioned at least partially within the casing and configured to provide a flow of compressed airflow through the opening in a repeating pattern during an operating condition of the gas turbine engine.

Abstract: A turbofan engine is provided. The turbofan engine includes a fan comprising a plurality of fan blades; and a nacelle that circumferentially surrounds the fan, the nacelle comprising an annular wall having an exterior surface and an interior surface, the exterior surface comprising a first exterior portion, and the interior surface comprising a first interior portion, wherein a first exterior portion is formed of a first structure defining an exterior surface porosity, and wherein a first interior portion is formed of a second structure defining an interior surface porosity.

Abstract: A cascade thrust reverser assembly for a gas turbine engine includes a nacelle assembly defining a bypass passage. The cascade thrust reverser assembly includes a cascade assembly configured to be at least partially enclosed by the nacelle assembly, the cascade assembly comprising one or more cascade members, the one or more cascade members movable between a stowed configuration wherein the one or more cascade members define a first radial extent and a deployed configuration wherein the one or more cascade members define a second radial extent, wherein the one or more cascade members form a cascade segment in the deployed configuration, and wherein the second radial extent is greater than the first radial extent.

Abstract: An acoustic core includes an array of resonant cells. The array may include a plurality of coupled resonant cells respectively defining an antecedent resonant space and a subsequent resonant space, with at least one cell wall having one or more wall-apertures defining a pathway between the antecedent resonant space and the subsequent resonant space. The array may include a plurality of high-frequency resonant cells respectively defining a high-frequency resonant space and being matched with respective ones of the plurality of coupled resonant cells. A cross-sectional dimension of the one or more wall-apertures defining the pathway between the antecedent resonant space and the subsequent resonant space may be less than a cross-sectional dimension of the antecedent resonant space and/or a cross-sectional dimension of the subsequent resonant space.

Abstract: Systems and methods for controlling an unducted turbofan engine to limit noise. The unducted turbofan engine may include an unducted fan drivingly coupled with a low-pressure turbine and a plurality of unducted outlet guide vanes. The unducted fan may include a plurality of fan blades and a pitch angle of the fan blades may be variable. A pitch angle of the unducted outlet guide vanes may be variable. A controller is configured to control the engine to limit noise based on a noise sensitive condition.

Abstract: An acoustic core may include an array of resonant cells configured as a plurality of resonant cell groups. The resonant cell groups may include a plurality of resonant cells configured as a partitioned resonant cell that include a converging resonant cell and a diverging resonant cell. The converging resonant cell and the diverging resonant cell may be defined by a plurality of cell walls integrally formed with one another and a partition integrally formed with the plurality of cell walls. The partition may at least partially delimit the converging resonant cell from the diverging resonant cell. The converging resonant cell may define an upper resonant space delimited by the partition and a top face of the array of resonant cells. The diverging resonant cell may define a lower resonant space delimited by the partition and a bottom face of the array of resonant cells.