Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed for passive fan blade tip clearance control. A fan blade for a gas turbine engine, the fan blade comprising a fan blade body including a tip region at a blade tip of the fan blade body and a blade tip insert disposed within the tip region of the fan blade body, the blade tip insert is formed from a material that passively adjusts a shape of the blade tip insert to maintain a blade tip clearance between the blade tip and an engine casing or nacelle by at least one of expanding or contracting based on temperature.

Abstract: Disclosed herein are example variable flowpath casings for blade tip clearance control. An example casing for a turbine engine includes an annular substrate extending along an axial direction, the annular substrate including a first surface and a second surface that is radially inward relative to the first surface; an actuator structure coupled to the second surface of the annular substrate; and a smart structure cantilevered from the second surface of the annular substrate, the smart structure including: a support structure, a first region of the support structure coupled to the second surface of the annular substrate, a second region of the support structure coupled to the actuator structure; and a radially inward surface defining a variable surface, the support structure to move the variable surface in a radial direction.

Abstract: Disclosed herein are example variable flowpath casings for blade tip clearance control. An example casing for a turbine engine includes an annular substrate extending along an axial direction, the annular substrate defining a cavity at a radially inward surface of the annular substrate, and a smart structure coupled to the annular substrate, the smart structure including a support structure; an actuator structure to at least one of expand or contract in response to a change in temperature of the actuator structure, and a variable surface coupled to the support structure, the support structure to move the variable surface in a radial direction.

Abstract: Light weight fan casing configurations for energy absorption are disclosed herein. An apparatus includes a first set of metal bands positioned within a containment casing of a turbofan engine, and a second set of metal bands traversing the first set of metal bands, the first set of metal bands and the second set of metal bands to surround at least a portion of the turbofan engine.

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 turbine engine can comprise a fan section, compressor section, a combustion section, and a turbine section in axial flow arrangement. At least one of the fan section and compressor section can include an airfoil with a leading edge, and a plurality of riblets can be arranged on the leading edge.

Abstract: An airfoil including a plurality of composite plies extending from a leading edge to a trailing edge and between a tip and a root. The airfoil further includes a frangible airfoil portion at the tip extending between the leading edge and the trailing edge and extending between the tip and a frangible line along a span including a first plurality of composite plies. Each of the first plurality of composite plies includes fibers oriented at least partially along a chordwise direction, a thickness direction, or both. The airfoil further includes a residual airfoil portion extending from the frangible line to the root along the span including a second plurality of composite plies. The second plurality of composite plies includes at least one composite ply with fibers oriented along the span. Further, the residual airfoil portion meets the frangible airfoil portion at the frangible line.

Abstract: A blade for a propulsion apparatus. The blade includes a body having opposed pressure and suction sides. The blade extends in span between a root and a tip and the blade extends in chord between a leading edge and a trailing edge. The blade includes a fracture structure that is defined within the body and positioned such that it is spaced-away from the tip. The fracture structure includes at least one chamber. A first fracture wall is disposed between the at least one chamber and the pressure side, and a second fracture wall is disposed between the at least one chamber and the suction side. The fracture structure is configured to fail when a predetermined force is applied to the tip such that the tip separates from the remainder of the body.

Abstract: An airfoil defining a span extending between a root and a tip and a chord at each point along the span extending between a leading edge and a trailing edge. The airfoil includes a blade extending between the root and tip and extending between the leading edge and trailing edge. The blade includes a pressure side and a suction side defining a thickness therebetween at each point along the span. The blade defines a first chord reduction on at least one of the leading edge or trailing edge along a first portion of the span. Further, the blade defines a frangible line extending from the first chord reduction at least partially along the chord at a point along the span within the first portion of the span.

Abstract: An airfoil defining a span extending between a root and a tip and a chord at each point along the span extending between a leading edge and a trailing edge. The airfoil includes a blade extending between the root and tip and extending between the leading edge and trailing edge. The blade includes a pressure side and a suction side defining a thickness therebetween at each point along the span. The blade defines a first chord reduction on at least one of the leading edge or trailing edge along a first portion of the span. Further, the blade defines a frangible line extending from the first chord reduction at least partially along the chord at a point along the span within the first portion of the span.

Abstract: An airfoil including a plurality of composite plies extending from a leading edge to a trailing edge and between a tip and a root. The airfoil further includes a frangible airfoil portion at the tip extending between the leading edge and the trailing edge and extending between the tip and a frangible line along a span including a first plurality of composite plies. Each of the first plurality of composite plies includes fibers oriented at least partially along a chordwise direction, a thickness direction, or both. The airfoil further includes a residual airfoil portion extending from the frangible line to the root along the span including a second plurality of composite plies. The second plurality of composite plies includes at least one composite ply with fibers oriented along the span. Further, the residual airfoil portion meets the frangible airfoil portion at the frangible line.

Abstract: An airfoil material loss control structure is provided. This structure includes at least one fuse zone that, during impact from a foreign object, fail before the surrounding structure. In a further aspect, a rotary machine is provided. This rotary machine includes a ducted fan gas turbine engine including a composite airfoil with at least one fuse zone.

Abstract: A blade for a propulsion apparatus. The blade includes a body having opposed pressure and suction sides. The blade extends in span between a root and a tip and the blade extends in chord between a leading edge and a trailing edge. The blade includes a fracture structure that is defined within the body and positioned such that it is spaced-away from the tip. The fracture structure includes at least one chamber. A first fracture wall is disposed between the at least one chamber and the pressure side, and a second fracture wall is disposed between the at least one chamber and the suction side. The fracture structure is configured to fail when a predetermined force is applied to the tip such that the tip separates from the remainder of the body.

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 turbine engine can comprise a fan section, compressor section, a combustion section, and a turbine section in axial flow arrangement. At least one of the fan section and compressor section can include an airfoil with a leading edge, and a plurality of riblets can be arranged on the leading edge.

Abstract: An airfoil material loss control structure is provided. This structure includes at least one fuse zone that, during impact from a foreign object, fail before the surrounding structure. In a further aspect, a rotary machine is provided. This rotary machine includes a ducted fan gas turbine engine including a composite airfoil with at least one fuse zone.