Abstract: Thermal control system for aircraft main landing gear wheel wells and related methods are disclosed. An example thermal control system includes a conduit defining a fluid passageway between an inlet and an outlet. The inlet of the conduit positioned in fluid communication with a landing gear wheel well and the outlet of the conduit positioned in fluid communication with the atmosphere. The conduit generates a pressure differential through the fluid passageway between the inlet and the outlet to exhaust heat from the landing gear wheel well to the atmosphere.

Abstract: An environmental aspect control assembly is configured to control one more environmental aspects. The environmental aspect control assembly may include at least one aspect-controlling portion formed of one or more environmental aspect-controlling materials, and at least one shape-changing actuator operatively connected to the aspect-controlling structure(s). The shape-changing actuator(s) is configured to have a first actuator shape at a first temperature and a second actuator shape at a second temperature that differs from the first temperature. The first actuator shape causes the aspect-controlling structure(s) to form a first structural shape. The second actuator shape causes the aspect-controlling structure(s) to form a second structural shape that differs from the first structural shape.

Abstract: Systems and methods are provided for controlling hydraulic valves. One embodiment is a method that includes blocking an orifice for a return line of a hydraulic valve via a flapper assembly, initiating a phase change in a Shape Memory Alloy (SMA) at the flapper assembly, and opening the orifice for the return line via the flapper assembly in response to the phase change.

Abstract: An environmental aspect control assembly is configured to control one more environmental aspects. The environmental aspect control assembly may include at least one aspect-controlling portion formed of one or more environmental aspect-controlling materials, and at least one shape-changing actuator operatively connected to the aspect-controlling structure(s). The shape-changing actuator(s) is configured to have a first actuator shape at a first temperature and a second actuator shape at a second temperature that differs from the first temperature. The first actuator shape causes the aspect-controlling structure(s) to form a first structural shape. The second actuator shape causes the aspect-controlling structure(s) to form a second structural shape that differs from the first structural shape.

Abstract: Variable-porosity panel systems and associated methods. A variable-porosity panel system includes a panel assembly with an exterior layer defining a plurality of exterior layer pores and a sliding layer adjacent to the exterior layer and defining a plurality of sliding layer pores. The variable-porosity panel system additionally includes a shape memory alloy (SMA) actuator configured to translate the sliding layer relative to the exterior layer to modulate a porosity of the panel assembly. The SMA actuator includes an SMA element configured to exert an actuation force on the sliding layer and at least partially received within an SMA element receiver of the sliding layer. The SMA element extends out of the sliding layer only at a sliding layer first end. A method of operating the variable-porosity panel system includes assembling the variable-porosity panel system and/or transitioning the panel assembly of the variable-porosity panel system among the plurality of panel configurations.

Abstract: A vortex generator, includes a vane, mountable on an aerodynamic surface of an aircraft, and an actuator that rotates the vane between a stowed position and a deployed position. The actuator includes a linear actuator, composed at least in part of a shape memory alloy (SMA), that when thermally activated facilitates rotation of the vane between the stowed position to the deployed position. Thermal activation of the SMA is caused via one or more of joule heating, conduction, and induction in response to one or more of an electronic command signal and a wireless command signal. The electronic command signal and the wireless command signal may be transmitted in response to ambient conditions, aircraft flight conditions, and aircraft mission.

Abstract: A variable geometry aerodynamic blade system employs a blade having a leading edge and a trailing edge. At least one shape memory alloy component is integrated in the blade for aerodynamic repositioning of one or both of the leading and trailing edges. At least one heating element interacts with the at least one shape memory alloy component to provide heating for transition between an austenitic and a martensitic phase. The at least one shape memory alloy component is responsive to the at least one heating element to alter one of a camber and twist of the blade responsive to a control signal. A control system is operatively engaged to the at least one heating element, the control system receiving a command signal and outputting the control signal responsive to the command signal.

Abstract: Variable-porosity panel systems and associated methods. A variable-porosity panel system includes a panel assembly with an exterior layer defining a plurality of exterior layer pores and a sliding layer adjacent to the exterior layer and defining a plurality of sliding layer pores. The variable-porosity panel system additionally includes a shape memory alloy (SMA) actuator configured to translate the sliding layer relative to the exterior layer to modulate a porosity of the panel assembly. The SMA actuator includes an SMA element configured to exert an actuation force on the sliding layer and at least partially received within an SMA element receiver of the sliding layer. The SMA element extends out of the sliding layer only at a sliding layer first end. A method of operating the variable-porosity panel system includes assembling the variable-porosity panel system and/or transitioning the panel assembly of the variable-porosity panel system among the plurality of panel configurations.

Abstract: A vortex generator, includes a vane, mountable on an aerodynamic surface of an aircraft, and an actuator that rotates the vane between a stowed position and a deployed position. The actuator includes a linear actuator, composed at least in part of a shape memory alloy (SMA), that when thermally activated facilitates rotation of the vane between the stowed position to the deployed position. Thermal activation of the SMA is caused via one or more of joule heating, conduction, and induction in response to one or more of an electronic command signal and a wireless command signal. The electronic command signal and the wireless command signal may be transmitted in response to ambient conditions, aircraft flight conditions, and aircraft mission.

Abstract: Certain aspects of the present disclosure provide an apparatus. The apparatus includes a first hinge element configured to engage and secure to a fixed element; a second hinge element configured to engage and secure to a movable element and to pivot about an axis of rotation defined by a hinge pin passing through at least one bore of the first hinge element and at least one bore of the second hinge element; and a first shape memory alloy element disposed coaxially within a bore of the hinge pin; a first heating element disposed coaxially within the bore of the hinge pin and configured to heat the first shape memory alloy element, wherein the hinge pin includes a first flange configured to engage the first hinge element; and a second flange configured to engage the second hinge element.

Abstract: Systems and methods are provided for controlling hydraulic valves. One embodiment is a method that includes blocking an orifice for a return line of a hydraulic valve via a flapper assembly, initiating a phase change in a Shape Memory Alloy (SMA) at the flapper assembly, and opening the orifice for the return line via the flapper assembly in response to the phase change.

Abstract: Thermal control system for aircraft main landing gear wheel wells and related methods are disclosed. An example thermal control system includes a conduit defining a fluid passageway between an inlet and an outlet. The inlet of the conduit positioned in fluid communication with a landing gear wheel well and the outlet of the conduit positioned in fluid communication with the atmosphere. The conduit generates a pressure differential through the fluid passageway between the inlet and the outlet to exhaust heat from the landing gear wheel well to the atmosphere.

Abstract: A method of fabricating a plank stringer for use in an aircraft includes grouping a plurality of stacked plies of reinforcing material into a plurality of charges, where each charge in the plurality of charges includes a substack of plies. The method also includes grouping the plurality of charges into two or more groups such that, for each charge in a given group, a respective substack of plies includes a sequence of orientation angles with respect to a longitudinal axis of the plank stringer corresponding to the given group. The method also includes laying up each group of charges as a continuous blanket of plies, where each continuous blanket of plies includes the respective substack of plies for each charge in the respective group. The method also includes cutting each continuous blanket of plies into the respective group of charges and stacking the plurality of charges to form the plank stringer.

Abstract: A variable geometry aerodynamic blade system employs a blade having a leading edge and a trailing edge. At least one shape memory alloy component is integrated in the blade for aerodynamic repositioning of one or both of the leading and trailing edges. At least one heating element interacts with the at least one shape memory alloy component to provide heating for transition between an austenitic and a martensitic phase. The at least one shape memory alloy component is responsive to the at least one heating element to alter one of a camber and twist of the blade responsive to a control signal. A control system is operatively engaged to the at least one heating element, the control system receiving a command signal and outputting the control signal responsive to the command signal.

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: 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 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: A method of fabricating a plank stringer for use in an aircraft includes grouping a plurality of stacked plies of reinforcing material into a plurality of charges, where each charge in the plurality of charges includes a substack of plies. The method also includes grouping the plurality of charges into two or more groups such that, for each charge in a given group, a respective substack of plies includes a sequence of orientation angles with respect to a longitudinal axis of the plank stringer corresponding to the given group. The method also includes laying up each group of charges as a continuous blanket of plies, where each continuous blanket of plies includes the respective substack of plies for each charge in the respective group. The method also includes cutting each continuous blanket of plies into the respective group of charges and stacking the plurality of charges to form the plank stringer.

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 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.