Abstract: A composite sandwich structure for a vehicle includes a first sheet that has a first surface and an opposing second surface. The composite sandwich structure also includes a second sheet opposite the first sheet and a core coupled between the first and second sheets. The core is formed from a shape memory alloy and is configured to reversibly transform between (a) a substantially fully austenite state in response to the composite sandwich structure being within an expected operating temperature range and being subjected to a relatively low transverse force, and (b) an at least partially martensite state in response to the composite sandwich structure being within the expected operating temperature range and being subjected to a relatively high transverse force. Each of a plurality of first portions of the core correspondingly changes shape to accommodate the application of the relatively high force, such that the core reversibly deforms.

Abstract: The present disclosure describes ventilation systems having a reduced aerodynamic footprint. The vents in the ventilation systems are actuated with Shape Memory Alloys that actuate the vents on an as needed basis while effectively sealing the vents when not in operation. The present disclosure further describes a ventilation system in an aircraft nacelle that helps mitigate bowed rotors by cooling down the engine nacelle faster or by helping create a uniform temperature distribution in the nacelle. In various embodiments, the ventilation system comprises vents and fans embedded in the vents.

Abstract: A power-assist apparatus includes a shape-memory alloy (SMA) rod, a power source, an actuator, and a differential gearbox. The SMA rod configured to rotate at an end of the SMA rod. The power source is coupled to the SMA rod. The actuator coupled to an openable apparatus. The differential gearbox is coupled between the actuator and the SMA rod. The differential gearbox converts the rotation of the SMA rod to motion of the actuator.

Abstract: Disclosed herein is an actuator for effectuating a shape memory alloy (SMA). The actuator includes a body including shape memory alloy. The body includes a plurality of segments. The actuator also includes a plurality of heaters that are each configured to maintain a predetermined temperature based on a predetermined resistance of the heater when a voltage is applied to the heater. Each heater of the plurality of heaters is associated with a different segment of the plurality of segments. A segment of the plurality of segments is effectuated in response to increasing a temperature of the heater associated with the segment.

Abstract: An engine turning “clock work” motor including two shape memory alloy (SMA) torque tube actuators, ratcheting mechanisms, and gearing. The gearing communicates the SMA torque tube actuators with a common gear that applies torque to a shaft, so that while one torque tube is heated and applying torque, the other torque tube is relaxed (using a cooling mechanism). The ratchet prevents the relaxing torque tube from applying torque in the incorrect direction.

Abstract: A shape memory alloy (SMA) actuated aerostructure operable to dynamically change shape according to flight conditions is disclosed. Deformable structures are actuated by SMA actuators that are coupled to face sheets of the deformable structures. Actuating the SMA actuators produces complex shape changes of the deformable structures by activating shape changes of the SMA actuators. The SMA actuators are actuated via an active or passive temperature change based on operating conditions. The SMA actuated aerostructure can be used for morphable nozzles such as a variable area fan nozzle and/or a variable geometry chevron of a jet engine to reduce engine noise during takeoff without degrading fuel burn during cruise.

Abstract: An aircraft includes a plurality of seats and an input device coupled to each of the plurality of seats. The aircraft also includes a remotely controlled nozzle positioned proximate each seat of the plurality of seats. Each nozzle includes an actuator assembly including at least one actuator and an actuator shaft. The at least one actuator is configured to move the actuator shaft between an open position and a closed position to control an airflow through the nozzle in response to a signal received from a respective input device of the input devices, wherein the signal represents a position of the actuator shaft.

Abstract: Methods and systems for a butterfly valve including a shape memory alloy (SMA) tube trained for rotation are presently disclosed. The SMA tube has a ground end coupled to a housing and rotating end coupled to a plate. The SMA tube is configured to rotate in a first direction in response to a first temperature change of the SMA tube. When rotating in the first direction, the rotating end of the SMA tube rotates and deflects the plate to rotate in a direction that permits a medium to flow through the valve. The SMA tube is also configured to rotate in a second direction in response to a second temperature change of the SMA tube. When rotating in the second direction, the rotating end of the SMA tube rotates and deflects the plate to rotate in a direction that does not permits a medium to flow through the valve.

Abstract: A system reproduces aerodynamic boundary layer transition conditions in a wind tunnel test environment under ambient to cryogenic temperature conditions. The system includes a test component disposed in the test environment that defines an exterior surface. A trip dot is mounted on the test component and has a first state, in which a distal surface of the trip dot is at a first elevation relative to the exterior surface of the test component, and a second state, in which the distal surface of the trip dot is at a second elevation relative to the exterior surface of the test component. An actuator is operably coupled to the trip dot and configured to transition the trip dot between first and second states. A controller remotely causes the actuator to transition the trip dot between the first and second states.

Abstract: The present disclosure describes ventilation systems having a reduced aerodynamic footprint. The vents in the ventilation systems are actuated with Shape Memory Alloys that actuate the vents on an as needed basis while effectively sealing the vents when not in operation. The present disclosure further describes a ventilation system in an aircraft nacelle that helps mitigate bowed rotors by cooling down the engine nacelle faster or by helping create a uniform temperature distribution in the nacelle. In various embodiments, the ventilation system comprises vents and fans embedded in the vents.

Abstract: A thermal energy harvesting system employs a hot flow conduit and a cold flow conduit with a flow routing device interruptibly interconnecting the hot flow conduit and cold flow conduit with a flow casing. At least one shape memory actuator (SMA) tube is in fluid contact with the flow casing and fixed at a first end. The flow routing device sequentially supplies hot flow from the hot flow conduit and cold flow from the cold flow conduit inducing rotation of the at least one SMA tube at a second end. A generator or alternator is operably connected to the second end of the at least one SMA tube.

Abstract: A method and apparatus for a boundary layer control device located relative to an aircraft structure. The boundary layer control device has a stowed position and a deployed position. The boundary layer control device moves from the stowed position to the deployed position. A thickness of a boundary layer for the aircraft structure increases in a manner that increases a distance of a heat flow field from the aircraft structure during operation of the aircraft.

Abstract: Disclosed herein is a flow control device. The flow control device comprises a sheet made from a shape memory alloy. The flow control device also comprises at least one slit through the sheet. At least the one slit defines at least one flap in the sheet. The flow control device further comprises at least one electrically-resistive trace printed on the sheet at least one of on or adjacent at least the one flap. Upon receipt of an electrical current, at least the one electrically-resistive trace configured to generate heat for deforming at least the one flap relative to the sheet and opening an aperture formed in the sheet.

Abstract: Disclosed herein is an actuator for effectuating a shape memory alloy (SMA). The actuator includes a body including shape memory alloy. The body includes a plurality of segments. The actuator also includes a plurality of heaters that are each configured to maintain a predetermined temperature based on a predetermined resistance of the heater when a voltage is applied to the heater. Each heater of the plurality of heaters is associated with a different segment of the plurality of segments. A segment of the plurality of segments is effectuated in response to increasing a temperature of the heater associated with the segment.

Abstract: A shape memory alloy (SMA) actuated aerostructure operable to dynamically change shape according to flight conditions is disclosed. Deformable structures are actuated by SMA actuators that are coupled to face sheets of the deformable structures. Actuating the SMA actuators produces complex shape changes of the deformable structures by activating shape changes of the SMA actuators. The SMA actuators are actuated via an active or passive temperature change based on operating conditions. The SMA actuated aerostructure can be used for morphable nozzles such as a variable area fan nozzle and/or a variable geometry chevron of a jet engine to reduce engine noise during takeoff without degrading fuel burn during cruise.

Abstract: In one or more aspects of the present disclosure, a mandrel is disclosed. The mandrel having a shape memory alloy (SMA) shell having a longitudinal axis, an interior extending along the longitudinal axis and an exterior contour, the SMA shell being configured to interface with a structure to be cured, and at least one SMA actuation member disposed within the interior and connected to the SMA shell, where the at least one SMA actuation member is configured to exert pressure against the SMA shell effecting an interface pressure between the exterior contour of the SMA shell and the structure to be cured where the exterior contour has a predetermined actuated shape that corresponds to a predetermined cured shape of the structure to be cured.

Abstract: A scalable multi-element shape memory alloy (SMA) rotary motor employs a plurality of SMA tubes. A ratcheting gear transmission couples the plurality of SMA tubes in parallel to a common output. A controller provides power to a plurality of heaters associated with each of the plurality of SMA tubes, sequentially heating selected heaters to provide continuous rotational motion of the common output.

Abstract: A shape memory structure includes a plurality of bases directly attached to a composite structure and arranged along a first line at a first edge of the composite structure. A plurality of buckle-shaped shape memory structures are attached to corresponding ones of the plurality of bases, such that first ends of the plurality of buckle-shaped shape memory structures are raised relative to the composite structure. Second ends of the plurality of buckle-shaped shape memory structures are directly attached to the composite structure along a second line at a second edge of the composite structure, the second edge being opposite the first edge. When activated, the shape memory structure changes from a buckled shape to an original shape to cause the composite structure to assume a deployed shape; when deactivated, the shape memory structure to resumes a buckled shape and the composite structure an undeployed shape.

Abstract: Aspects of the present disclosure generally relate to an SMA actuator that includes a cooling device disposed within a torque tube. In one aspect, the cooling device includes a sliding sleeve, an expandable sleeve, and plurality of cooling fins coupled to the expandable sleeve. Axial movement of the sliding sleeve relative to the expandable sleeve facilitates radial expansion of the expandable sleeve and urges the cooling fins into contact with the torque tube. The cooling fins function as heat sinks when in contact with the torque tube to facilitate the removal of heat from the torque tube to increase the cooling rate of the torque tube. During heating of the torque tube, the cooling fins may be spaced apart from the torque tube to reduce the thermal mass that is heated, thus increasing the heating rate of the torque tube.

Abstract: A system for heating a shape memory alloy (SMA) actuator may include an SMA actuator, a smart susceptor, a plurality of induction coils, and a control module. The SMA actuator may have at least one layup. The SMA actuator may be selectively heated to a transition temperature. The smart susceptor may be in thermal contact with the at least one layup of the SMA actuator. The induction heating coils may be configured to receive an alternating current and generate a magnetic field based on the alternating current. The magnetic field may create an eddy current in at least one of the SMA actuator and the smart susceptor to heat the SMA actuator to the transition temperature. The control module may be configured to drive the alternating current supplied to the induction heating coils.