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: A build unit for additively manufacturing three-dimensional objects may include an energy beam system having one or more irradiation devices respectively configured to direct one or more energy beams onto a region of a powder bed, and an inertization system including an irradiation chamber defining an irradiation plenum, one or more supply manifolds, and a return manifold. The one or more supply manifolds may include a downflow manifold configured to provide a downward flow of a process gas through at least a portion of the irradiation plenum defined by the irradiation chamber, and/or a crossflow manifold configured to provide a lateral flow of the process gas through at least a portion of the irradiation plenum defined by the irradiation chamber. The return manifold may evacuate or otherwise remove process gas from the irradiation plenum defined by the irradiation chamber.

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: An inlet duct for a nacelle of a ducted fan engine includes an inlet portion at an upstream end of the inlet duct, an acoustic liner arranged downstream of the inlet portion, and a fan section arranged downstream of the acoustic liner. The inlet portion and the acoustic liner are coupled together at an inlet-acoustic liner interface extending circumferentially about the inner surface of the inlet duct, and the acoustic liner and the fan section are coupled together at a fan section hardwall-acoustic liner interface extending circumferentially about the inner surface of the inlet duct. At least one of the acoustic liner, the inlet-acoustic liner interface, and the fan section hardwall-acoustic liner interface having a structure that circumferentially alters a magnitude and a phase of an acoustic wave reflection of the inlet duct to attenuate flutter bite of a fan.

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: Methods, apparatus, systems, and articles of manufacture are disclosed to implement an integrated stator-fan frame assembly. An integrated fan exit stator-fan frame strut assembly for a gas turbine engine includes a fan exit stator portion having an airfoil including a leading edge and a trailing edge, and a fan frame strut portion including a leading edge and a trailing edge, the leading edge of the fan frame strut portion aerodynamically integrated with the trailing edge of the fan exit stator portion.

Abstract: Disclosed examples include an airfoil comprising: a pressure side and a suction side that are coupled together at a substantially radial trailing edge of the airfoil, wherein the substantially radial trailing edge is downstream from a leading edge, the leading edge including a sweep feature of a variable chord length, the variable chord length to include: a first increase in chord length and a decrease in chord length along a radial length from a hub end of the airfoil to an opposite tip end of the airfoil; and a second increase in chord length along the radial length from the hub end to the opposite tip end, the second increase different than the first increase.

Abstract: A turbomachine includes an annular casing and a fan disposed inside the annular casing and mounted for rotation about an axial centerline. The fan includes fan blades that extend radially outwardly toward the annular casing. The fan has an average chord fan width according to a first performance factor. The fan has a quantity of fan blades according to a second performance factor.

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: Methods, apparatus, systems, and articles of manufacture are disclosed to implement a low radius ratio fan blade for a gas turbine engine. A fan blade for a gas turbine engine includes an airfoil including a leading edge and a trailing edge extending between a root and a tip of the airfoil, a distance between the leading edge and the trailing edge defining a flow path length, a leading edge hub point defined by a radially innermost point of the leading edge, and an axial dovetail including a pair of opposed pressure faces, an axial length of the axial dovetail less than the flow path length, a top edge of the axial dovetail separating the pressure faces from the airfoil, the top edge of the axial dovetail radially outward of the leading edge hub point.

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: An unducted single fan engine includes a housing having one or more fan blades coupled to the housing and configured to rotate circumferentially. The engine has one or more outlet guide vanes coupled to the housing. Each of the one or more guide vanes has a leading edge portion having a variable leading edge. The engine has one or more actuation devices coupled to each of the one or more outlet guide vanes. The one or more actuation devices are configured to control the variable leading edge of the respective outlet guide vane. The variable leading edge is controllable to vary the pitch, camber, lean angle, or sweep of the respective outlet guide vane.

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 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: A build unit for additively manufacturing three-dimensional objects may include an energy beam system having one or more irradiation devices respectively configured to direct one or more energy beams onto a region of a powder bed, and an inertization system including an irradiation chamber defining an irradiation plenum, one or more supply manifolds, and a return manifold. The one or more supply manifolds may include a downflow manifold configured to provide a downward flow of a process gas through at least a portion of the irradiation plenum defined by the irradiation chamber, and/or a crossflow manifold configured to provide a lateral flow of the process gas through at least a portion of the irradiation plenum defined by the irradiation chamber. The return manifold may evacuate or otherwise remove process gas from the irradiation plenum defined by the irradiation chamber.