Abstract: A vortex generator may include a depression in an aerodynamic surface, and a vortex generator leading edge located in the depression. The vortex generator leading edge may include a leading edge upper surface. The leading edge upper surface may be positioned at or below a tangent line defined at a location along the aerodynamic surface upstream of the depression relative to an oncoming local flow.

Abstract: An airfoil may include a leading edge and a shape control mechanism. The leading edge may include a flexible leading edge skin having a first end, a second end, and an arc length defined therebetween. The shape control mechanism may be attached to the flexible leading edge skin at a plurality of support locations and may transition the flexible leading edge skin from a first shape having a first curvature profile to a second shape having a second curvature profile different than the first curvature profile without a change in the arc length.

Abstract: Apparatus and methods provide for a swept-wing powered-lift aircraft. Aspects of the disclosure provide a powered-lift aircraft that utilizes the engine exhaust flow over upper surface blown flaps to increase lift during various flight operations. The powered-lift aircraft has wings with inboard portions and outboard portions. The adjacent inboard and outboard portions share a swept leading edge. The leading edge is swept to a degree that shifts the outboard portion rearward to a position in which the aircraft center of lift has little to no variance upon the activation or deactivation of a powered-lift system.

Abstract: Apparatus and methods provide for a swept-wing powered-lift aircraft. Aspects of the disclosure provide a powered-lift aircraft that utilizes the engine exhaust flow over upper surface blown flaps to increase lift during various flight operations. The powered-lift aircraft has wings with inboard portions and outboard portions. The adjacent inboard and outboard portions share a swept leading edge. The leading edge is swept to a degree that shifts the outboard portion rearward to a position in which the aircraft center of lift has little to no variance upon the activation or deactivation of a powered-lift system.

Abstract: Apparatus and methods provide for a controllable upper surface blown (USB) nozzle aperture. Aspects of the disclosure provide a powered-lift aircraft that utilizes a controllable nozzle aperture to maximize the spreading of the engine exhaust flow over the wing and USB flap surfaces to increase lift when desirable and to minimize exhaust plume contact with the wing and USB flap surfaces when minimizing drag is desirable. The controllable USB nozzle aperture includes movable upper, lower, and side duct surfaces to dynamically vary the geometry of the nozzle exit aperture to minimize the height and maximize the width of the exit aperture for maximum spreading of the exhaust plume or to maximize the height and minimize the width of the exit aperture for minimizing the spreading of the exhaust plume and minimizing the associated drag.

Abstract: Apparatus and methods provide for an aircraft configuration that utilize structural and engine exhaust flow control devices to enhance performance. Aspects of the disclosure provide a fuselage with a pressure vessel nested within a non-cylindrical outer mold line fairing. A twin-boom empennage may be connected to the fuselage. A wing may attach in a blended wing configuration with a sweep angle that positions the aircraft center of lift to minimize any pitching moment induced by the activation or deactivation of an upper surface blown (USB) system. The USB system may include a conformal USB flap positioned downstream of an engine exhaust plume, as well as a controllable USB nozzle aperture to promote exhaust flow attachment to the conformal USB flap. A universal convergent nozzle may be utilized to connect each controllable USB nozzle aperture to a corresponding internally mounted aircraft engine.

Abstract: Systems and methods are described for controlling flow disturbances emanating from a protrusion, such as a beam propagating device. In one embodiment, a method includes positioning a flow control element at least partially around a base portion of a protrusion, wherein the flow control element includes at least one flow expanding feature. A reduced pressure zone is generated proximate an aft portion of the protrusion by expanding at least a portion of a flowfield. One or more flow disturbances emanating downstream from the protrusion are deflected using the at least one reduced pressure zone.

Abstract: Systems and methods are described for controlling flow disturbances emanating from a protrusion, such as a beam propagating device. In one embodiment, a method includes positioning a flow control element at least partially around a base portion of a protrusion, wherein the flow control element includes at least one flow expanding feature. A reduced pressure zone is generated proximate an aft portion of the protrusion by expanding at least a portion of a flowfield. One or more flow disturbances emanating downstream from the protrusion are deflected using the at least one reduced pressure zone.

Abstract: An apparatus and method for controlling a throttle of an electronic throttle control-equipped engine including providing a throttle position feedback signal as a function of integer counts, each of the counts representing a resolution of a predetermined angle of actual throttle position, providing a desired throttle position command as a setpoint value being a function of half counts and generating an error signal representing a difference between the desired throttle position command value and the throttle position feedback signal value. A relay output signal is generated in response to the error signal, the relay output signal having one of two values depending upon a sign of the error signal and a direction of change of the error signal. A throttle actuator command is then generated as a function of the relay output signal value having a half count resolution.

Abstract: An apparatus and method for controlling a throttle of an electronic throttle control-equipped engine including providing a throttle position feedback signal as a function of integer counts, each of the counts representing a resolution of a predetermined angle of actual throttle position, providing a desired throttle position command as a setpoint value being a function of half counts and generating an error signal representing a difference between the desired throttle position command value and the throttle position feedback signal value. A relay output signal is generated in response to the error signal, the relay output signal having one of two values depending upon a sign of the error signal and a direction of change of the error signal. A throttle actuator command is then generated as a function of the relay output signal value having a half count resolution.