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.

In order to suppress aeroelastic instabilities on a transonically operating aircraft comprising a pair of wing halves at which a transonic flow forms spatially limited supersonic flow regions that each, in a main flow direction of the flow, end in a compression shock, a boundary layer of the flow is temporarily thickened-up in at least one supersonic flow region at at least one of the two wing halves, when approaching a flight envelope of the aircraft with increasing flight Mach number of the aircraft. The boundary layer of the flow is thickened-up to such an extent that the compression shock at the end of the respective supersonic flow region at the present flight Mach number of the aircraft induces a separation of the boundary layer of the flow from the wing half.

For dual management of anti-icing and boundary-layer suction, a system for an aerofoil of an aircraft, including: a channel having a double function of anti-icing and boundary-layer suction; a double-function main pipe to which a device for monitoring the boundary-layer suction and a device for monitoring anti-icing are connected; an anti-icing air-intake pipe connecting the main pipe and the channel; a non-return valve enabling anti-icing air to go from the main pipe to the pipe; at least one suction-air collection pipe connecting the channel and the main pipe; and a non-return valve enabling suction air to pass from the pipe toward the main pipe.

An aerodynamic structure for use on an upper surface of an aircraft wing is disclosed. The wing includes a slat operable between a stowed configuration in which the slat is stowed in a slat recess of the wing, and a deployed configuration in which the slat extends out of the slat recess. When the slat is in the deployed configuration, an end face of the slat recess is exposed, the end face intersecting with the upper surface of the wing at a recess edge. The aerodynamic structure, adjacent to the recess edge, has a volume shaped to encourage air flowing over the recess edge onto the upper surface during flight, to remain attached.

An aircraft is disclosed having a structure at least part of which is capable of generating aerodynamic lift. A body having a mass is movably mounted to a portion of the structure by an active support. The active support includes an actuator to move the body relative to the portion of the structure, and a controller for controlling movement of the actuator in response to a dynamic input. The active support provides a range of movement for the body in at least one degree of freedom. The actuator moves the body across the entire range of movement in that one degree of freedom in a time period of less than 3 seconds. The actuator moves the body sufficiently rapidly to generate an inertial force that is equal to or greater than any aerodynamic force generated by the body during that movement of the body. The active support may be used to reduce loads on the aircraft structure.

A boundary layer ingestion fan system for location aft of the fuselage of an aircraft is shown. It comprises a nacelle (501) defining a duct, and a fan located therewithin. The fan comprises a hub arranged to rotate around a rotational axis (A-A) and a plurality of blades attached thereto. Each blade has a span (r) from a root at the hub defining a 0 percent span position (r=0) to a tip defining a 100 percent span position (r=1) and a plurality of span positions therebetween (r ∈ [0, 1]), and leading and trailing edges defining, for each span position, a chord therebetween to having a chord length (c). For each of said plurality of blades, the ratio of chord length at the 0 percent span position (c.sub.hub) to chord length at the 100 percent span position (c.sub.tip) is 1 or greater.

A boundary layer ingestion fan system for location aft of the fuselage of an aircraft is shown. It comprises a nacelle (501) defining a duct (502), and a fan (503) located within the duct. The fan comprises a hub arranged to rotate around a rotational axis (A-A) and a plurality of blades attached to the hub. Each blade has a span (r) from a root at the hub defining a 0 percent span position (r=0) to a tip defining a 100 percent span position (r=1) and a plurality of span positions therebetween (r ∈ [0, 1]), and a stagger angle at the 0 percent span position (ζ.sub.hub) relative to the rotational axis of 40 degrees or greater.

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.

An aircraft includes an active drag control system such as a Laminar Flow Control (LFC) system having a port LFC apparatus and a starboard LFC apparatus. The aircraft has a control system to test how efficiently the LFC system is working by differentially operating the port LFC apparatus and the starboard LFC apparatus, for example by deactivating either LFC apparatus, and measuring the effect on the direction of flight of the aircraft. The control system also can change the direction of the aircraft, and trim the aircraft, by differentially operating the port LFC apparatus and the starboard LFC apparatus.

A vortex generator control system for a controlling an aircraft vortex generator arrangement comprising a controller configured to receive one or more deploy or retract command signals from a flight control unit and further configured to send one or more command signals to a fluid control valve, a fluid pressure sensor configured to sense one or more pressure values from an actuator of the vortex generator arrangement and to signal the pressure value(s) to the controller, wherein the fluid control valve is configured to control fluid transfer between the actuator and a reservoir in response to a command signal from the controller.