Abstract: An acoustic panel including a first face sheet having a plurality of openings; a core attached to the face sheet, the core comprising a plurality of cells each having cell walls; and a plurality of noise attenuating features each comprising at least one of the openings in combination with one of the cells, wherein the openings are disposed away from the cell walls so that the noise attenuating features suppress the transmission of acoustic waves in acoustic communication with the openings.

Abstract: A seal assembly configured to seal against a surface of a seal depressor includes a body member configured to elastically deform in at least a first direction of motion from an original state into a compressed state in response to experiencing a load. The body member exerts a sealing pressure against the surface of the seal depressor when in the compressed state. The seal assembly also includes one or more shape memory stiffening members constructed from a shape memory material having a high energy state and a low energy state. The one or more shape memory stiffening members are oriented perpendicular to the first direction of motion of the seal assembly and configured to stiffen the body member of the seal assembly when the shape memory material is in the high energy state.

Abstract: A seal assembly configured to seal against a surface of a seal depressor is disclosed. The seal assembly includes a body member configured to elastically expand from an original state into an expanded state. The body member exerts a sealing pressure against the surface of the seal depressor when in the expanded state. The seal assembly also includes one or more actuation members constructed from a shape memory material having a high energy state and a low energy state. The one or more actuation members are configured to urge the body member of the seal assembly from the original state into the expanded state when the shape memory material transitions from the low energy state to the high energy state.

Abstract: A labyrinth barrier is disclosed and comprises two or more members each defining respective vertical axes. One or more of the members are constructed at least in part of a shape memory material having a first energy state and a second energy state. The members are oriented relative to one another by their respective vertical axes in an original state to create a flow pathway that restricts fluid flow in a direction transverse to the respective vertical axes. The members are urged towards one another to further restrict the flow pathway when the shape memory material transitions from the first energy state to the second energy state.

Abstract: A seal assembly configured to seal against a surface of a seal depressor includes a body member configured to elastically deform in at least a first direction of motion from an original state into a compressed state in response to experiencing a load. The body member exerts a sealing pressure against the surface of the seal depressor when in the compressed state. The seal assembly also includes one or more shape memory stiffening members constructed from a shape memory material having a high energy state and a low energy state. The one or more shape memory stiffening members are oriented perpendicular to the first direction of motion of the seal assembly and configured to stiffen the body member of the seal assembly when the shape memory material is in the high energy state.

Abstract: A labyrinth barrier is disclosed and comprises two or more members each defining respective vertical axes. One or more of the members are constructed at least in part of a shape memory material having a first energy state and a second energy state. The members are oriented relative to one another by their respective vertical axes in an original state to create a flow pathway that restricts fluid flow in a direction transverse to the respective vertical axes. The members are urged towards one another to further restrict the flow pathway when the shape memory material transitions from the first energy state to the second energy state.

Abstract: A seal assembly configured to seal against a surface of a seal depressor is disclosed. The seal assembly includes a body member configured to elastically expand from an original state into an expanded state. The body member exerts a sealing pressure against the surface of the seal depressor when in the expanded state. The seal assembly also includes one or more actuation members constructed from a shape memory material having a high energy state and a low energy state. The one or more actuation members are configured to urge the body member of the seal assembly from the original state into the expanded state when the shape memory material transitions from the low energy state to the high energy state.

Abstract: Rotary electric engines, aircraft including the same, and associated methods. A rotary electric engine includes a nacelle, a fan configured to generate thrust, a stator operatively coupled to the nacelle, and a rotor operatively coupled to the fan. The fan includes a plurality of fan blades. The rotor includes a plurality of rotor magnets operatively coupled to respective blade tips of the fan blades. The stator includes a plurality of field coils configured to produce a magnetic interaction between the field coils and the rotor magnets to rotate the fan. In examples, the stator is configured to rotate each field coil relative to the nacelle. In examples, an aircraft includes one or more rotary electric engines pivotally mounted within engine mount regions. In examples, a method of operating an aircraft includes operating one or more rotary electric engines in a vertical lift configuration and in a forward flight configuration.

Abstract: An acoustic panel including an acoustic property varying as a function of a position in the acoustic panel relative to one or more sources of acoustic waves in acoustic communication with the acoustic panel, the acoustic waves having one or more acoustic signatures associated with the one or more sources, wherein the acoustic property is tailored, as a function of the position, to attenuate transmission of the acoustic waves having the one or more acoustic signatures.

Abstract: An acoustic panel including a first face sheet having a plurality of openings; a core attached to the face sheet, the core comprising a plurality of cells each having cell walls; and a plurality of noise attenuating features each comprising at least one of the openings in combination with one of the cells, wherein the openings are disposed away from the cell walls so that the noise attenuating features suppress the transmission of acoustic waves in acoustic communication with the openings.

Abstract: Systems, methods and computer program products for laser etching and robotic machining of large workpieces are disclosed. An example system includes a first ring of lasers configured to etch longitudinal gridlines on a workpiece, a second ring of lasers configured to etch circumferential gridlines on the workpiece, where the longitudinal gridlines and the circumferential gridlines define a working grid on the workpiece, and a machine vision system to scan the working grid and compare the working grid to a reference grid in a computer model of the workpiece and to determine offsets between the working grid and the reference grid for positioning a robotic machining tool.

Abstract: Systems and methods for leak detection of aircraft doors. One embodiment is an apparatus for leak testing a seal between an aircraft door and a fuselage of an aircraft. The apparatus includes a structural frame that includes a suction cup configured to suction an outer surface of the aircraft door. The structural frame further includes legs to extend in length to push the structural frame away from the fuselage and cause the suction cup to pull the aircraft door toward an outside of the aircraft to tighten the seal between the aircraft door and the fuselage of the aircraft.

Abstract: Rotary electric engines, aircraft including the same, and associated methods. A rotary electric engine includes a nacelle, a fan configured to generate thrust, a stator operatively coupled to the nacelle, and a rotor operatively coupled to the fan. The fan includes a plurality of fan blades. The rotor includes a plurality of rotor magnets operatively coupled to respective blade tips of the fan blades. The stator includes a plurality of field coils configured to produce a magnetic interaction between the field coils and the rotor magnets to rotate the fan. In examples, the stator is configured to rotate each field coil relative to the nacelle. In examples, an aircraft includes one or more rotary electric engines pivotally mounted within engine mount regions. In examples, a method of operating an aircraft includes operating one or more rotary electric engines in a vertical lift configuration and in a forward flight configuration.

Abstract: Systems, methods and computer program products for laser etching and robotic machining of large workpieces are disclosed. An example system includes a first ring of lasers configured to etch longitudinal gridlines on a workpiece, a second ring of lasers configured to etch circumferential gridlines on the workpiece, where the longitudinal gridlines and the circumferential gridlines define a working grid on the workpiece, and a machine vision system to scan the working grid and compare the working grid to a reference grid in a computer model of the workpiece and to determine offsets between the working grid and the reference grid for positioning a robotic machining tool.

Abstract: Hybrid turbine engines, aircraft including the same, and associated methods. A hybrid turbine engine includes a gas turbine engine mechanically and/or electrically coupled to a rotary electric engine. The rotary electric engine includes a nacelle, a fan with fan blades, a stator operatively coupled to the nacelle, and a rotor with a plurality of rotor magnets coupled to the fan blades. The stator includes a plurality of field coils. In examples, the stator is configured to rotate each field coil relative to the nacelle. In examples, an aircraft includes a hybrid turbine engine such that the gas turbine engine is substantially enclosed within the nacelle or is supported by a fuselage of the aircraft. In examples, a method of operating an aircraft with a hybrid turbine engine includes generating a gas turbine thrust with the gas turbine engine and generating an electric engine thrust with the rotary electric engine.

Abstract: Systems and methods for leak detection of aircraft doors. One embodiment is an apparatus for leak testing a seal between an aircraft door and a fuselage of an aircraft. The apparatus includes a structural frame that includes a suction cup configured to suction an outer surface of the aircraft door. The structural frame further includes legs to extend in length to push the structural frame away from the fuselage and cause the suction cup to pull the aircraft door toward an outside of the aircraft to tighten the seal between the aircraft door and the fuselage of the aircraft.