Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed for a slot to accommodate a blade of an engine. An example apparatus includes: a socket to receive an end of a blade; and a retaining device to interact with the socket and the blade for retention of the end of the blade in the socket. The example retaining device includes: a spacer to be positioned in the socket with the end of the blade; a wedge positioned inside the spacer; and a spring to tighten to pull the wedge to expand the spacer.

Abstract: Composite components and methods for forming composite components are provided. For example, a composite component of a gas turbine engine comprises a composite material, a plurality of piezoelectric fibers, and an anti-icing mechanism. The anti-icing mechanism is in operative communication with the piezoelectric fibers such that the anti-icing mechanism is activated by one or more electrical signals from the piezoelectric fibers. In exemplary embodiments, the composite component is a composite airfoil and the anti-icing mechanism is one or more heating elements. Methods for forming composite components may comprise forming piezoelectric plies comprising piezoelectric fibers embedded in a matrix material; forming reinforcing plies comprising reinforcing fibers embedded in the matrix material; laying up the piezoelectric and reinforcing plies to form a ply layup; and processing the ply layup to form the composite component.

Abstract: Methods, apparatus, systems and articles of manufacture corresponding to a fan blade with intrinsic damping characteristics are disclosed. An example fan blade comprises an exterior body including a first side and a second side; a first hairpin structure coupled to the first side of the exterior body and the second side of the exterior body; and a second hairpin structure coupled to the first side and the second side, the first hairpin structure in contact with the second hairpin structure.

Abstract: A variable stiffness damper system including an inner spring positioned between a first wall and a second wall, in which the inner spring includes a first member and a second member each coupled together at a distal end by an inner bumper. The first member and the second member are each contoured toward one another. The first member, the second member, and the inner bumper form a cavity therebetween. An outer spring is positioned between the inner spring and the first wall or the second wall. The outer spring includes a spring arm contoured toward the inner spring. The outer spring includes an outer bumper positioned between the inner bumper and the first wall or the second wall. The inner bumper and the outer bumper are selectively couplable to one another based on a load applied to the damper system.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed for a slot to accommodate a blade of an engine. An example blade apparatus includes: a collet including a slot to receive an end of a blade; and a plurality of retainers including a first retainer positioned on a first end of the collet and a second retainer positioned on a second end of the collet to provide axial retention for the blade in the slot.

Abstract: A gas turbine engine is provided. The gas turbine engine defines a radial direction. The engine includes: an airfoil positioned within an airflow and extending between a root end and a tip along the radial direction; and a mount coupled to or formed integrally with the root end of the airfoil for mounting the airfoil to the engine, the mount including an outer surface along the radial direction exposed to the airflow and defining an air-cooling channel extending between an inlet and an outlet, the inlet positioned on the outer surface of the mount.

Abstract: An airfoil that includes an airfoil body having a root and a tip, and convex and concave sides that extend between a leading edge and a trailing edge. The airfoil also includes at least a first cladding element that is attached to the airfoil body. The first cladding element includes a first portion and a second portion. The second portion is configured to separate from the first portion when the first cladding element encounters a force of at least a predetermined amount.

Abstract: A blade for a propulsion apparatus that includes a body formed of a first material having opposed pressure and suction sides, and extending in span between a root and a boundary, and extending in chord between a leading edge and a trailing edge. A tip region that is formed of a second material and that is positioned such that it extends from the body and defines a tip. The tip region joins the body at the boundary. The tip region is configured to fail when a predetermined force is applied to the tip such that the tip separates from the blade and defines a fused tip.

Abstract: A rotor disk for a gas turbine engine includes a disk body having a central bore extending therethrough. The disk body includes a bore body that extends around the central bore, a web that extends radially outward from the bore body having decreased thickness relative to the bore body and a peripheral rim that is located at an outer end of the web. The peripheral rim includes blade mounting structures for engaging complimentary mounting structures of rotor blades. The bore body has a bore cavity that extends continuously through the bore body and about an entire periphery of the central bore. The bore cavity has a central axis that forms a circle about the central bore.

Abstract: A booster splitter for a gas turbine engine and a method of additively manufacturing the booster splitter are provided. The booster splitter includes an annular inner wall defining a radially outer boundary of a compressor flow path defined through a compressor section of the gas turbine engine, an annular outer wall spaced apart from the annular inner wall along the radial direction, the annular outer wall adjacent to the annular inner wall at a forward end, the forward end defining an inlet to the compressor flow path, an annular bulkhead spanning between the annular inner wall and the annular outer wall substantially along the radial direction, the bulkhead defining an inlet port, and a passageway defined within the annular outer wall, the passageway extending from the inlet port, into the bulkhead, radially outward to the outer wall, and through the annular outer wall towards the inlet defined by the forward end.

Abstract: A rotor blade for a gas turbine engine includes an airfoil section and a root section extending along a longitudinal direction between an upstream surface and a downstream surface. The root section further extends along a radial direction between an inner surface positioned at an inner end of the root section and an outer end coupled to the airfoil section. Moreover, the root section extends along a circumferential direction between a first side surface and a second side surface. Furthermore, the root section defines a longitudinal centerline extending along the longitudinal direction and positioned equidistant from the inner surface and the outer end in the radial direction. The root section includes a first portion formed from a composite material and a second portion formed from a metallic material, with the longitudinal centerline extending through the second portion of the root section.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed to adjust a pitch axis of a blade of an engine. An example blade apparatus includes: a hub to facilitate movement of blades in an engine, the engine having a radial center line; and a trunnion connected to the hub. The example trunnion includes a slot to accommodate a first blade, and at least one of the trunnion or the first blade is positioned with at least one of a tilt or a lean with respect to the radial center line to form a pitch axis offset from the radial center line such that the pitch axis is not parallel to or co-linear with the radial center line. The example hub is to rotate the first blade about the pitch axis.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed for a slot to accommodate a blade of an engine. An example apparatus includes: a socket to receive an end of a blade; and a retaining device to interact with the socket and the blade for retention of the end of the blade in the socket. The example retaining device includes: a spacer to be positioned in the socket with the end of the blade; a wedge positioned inside the spacer; and a spring to tighten to pull the wedge to expand the spacer.

Abstract: An aircraft can include a turbine engine including a rotor and a stator, and also including a compressor, a combustor, and a turbine in axial flow arrangement. The aircraft can further include an anti-icing system with a magnetic field generator having a rotating portion and a non-rotating portion, as well as an array of carbon nanotubes thermally coupled to an exposed surface.

Abstract: A rotor assembly includes a fan rotor shaft coupled to a fan rotor, a low pressure turbine rotor shaft coupled to a low pressure turbine rotor, and a joint device configured to connect the fan rotor shaft to the low pressure turbine rotor shaft, to allow torsion, shear and bending to be transferred between the fan rotor shaft and the low pressure turbine rotor shaft under normal operation, and allow torsion and shear but prevent bending to be transferred between the fan rotor shaft and the low pressure turbine rotor shaft under a fan blade-out event.

Abstract: An aircraft can include an anti-icing system. The anti-icing system can include an array of carbon nanotubes thermally coupled to at least a first exposed surface of the aircraft. The anti-icing system can also include an array of solar cells carried by the aircraft and electrically coupled to the array of carbon nanotubes.

Abstract: A platform for use between adjacent propulsion rotor airfoils joined to a rotor disk to provide an inner flowpath boundary includes: an axially extending I-beam supporting a radially outer skin having a flowpath surface; the I-beam including an inner I-flange disposed at an inner edge of an axially extending I-web, and an outer I-flange disposed at an outer edge of the I-web; the I-beam including a laterally-extending forward end flange at a forward end of the I-web, and a laterally-extending aft end flange at an aft end of the I-web; and the radially outer skin disposed on top of and joined to the radially outer I-flange such that the forward end flange and the aft end flange abut the outer skin.

Abstract: A laminated composite airfoil assembly includes a first lamina formed of a material including metal fibers, and at least a second lamina formed of a material including at least one of metal fibers intermixed with carbon fibers, only metal fibers, only carbon fibers, a substrate including metal fibers, a substrate including carbon fibers, and combinations thereof.

Abstract: A turbine engine airfoil apparatus, including an airfoil defined by a plurality of airfoil sections arrayed along a stacking axis that extends between a root and a tip, wherein at least two of the airfoil sections spaced apart from each other have differing airfoil section thermal expansion properties.

Abstract: A softwall containment system for a machine includes an inner wall circumscribing a bladed rotatable member of the machine and extending from a forward end to an aft end. The softwall containment system also includes an outer wall circumscribing the inner wall and extending from a forward end to an aft end. The outer wall is spaced radially outwardly from the inner wall. The outer wall extends axially between a first joint coupling the forward end of the inner wall to the forward end of the outer wall and a second joint coupling the aft end of the inner wall to the aft end of the outer wall. The softwall containment system also includes an anti-ballistic material wrap covering the outer wall, the anti-ballistic material wrap including at least one of a first extension extending forward of the first joint and a second extension extending aft of the second joint.