A fixed wing drone comprises an air channel embedded therein. The air channel has an upstream an air inlet. A microcontroller mounted within the drone is configured to control navigation of the drone. An air scoop having a section positioned adjacent the inlet to the air channel is adjustable between a first position to capture and divert air into the inlet and thereby to air channel and a second position to block air flow into the air inlet. The air scoop is positioned to divert air flow into the air channel and to the gas sensor during forward flight of the drone. In one embodiment, the fixed wing drone comprises an aircraft having a fuselage and at least two wings. In another embodiment, the fixed wing drone has a flying wing construction, that is, is a tailless design.

A boundary layer control (BLC) system for embedment in a flight surface having a top surface, a bottom surface, a leading edge, and a trailing edge. The BLC system may comprises an actuator having a crossflow fan and an electric motor to drive the crossflow fan about an axis of rotation. The actuator may be embedded within the flight surface and adjacent the leading edge. In operation, the actuator is configured to output local airflow via an outlet channel through an outlet aperture adjacent the top surface to energize a boundary layer of air adjacent the top surface of the flight surface.

A leading edge structure for an aircraft flow control system includes a leading edge panel curvingly surrounding a plenum. The leading edge panel has a first side portion and a second side portion with an inner surface facing the plenum and an outer surface contacting an ambient flow. The leading edge panel includes a plurality of micro pores forming a fluid connection between the plenum and the ambient flow. An air outlet is arranged in the first or second side portion and is fluidly connected to the plenum for letting out air from the plenum into the ambient flow. The air outlet is formed as a fixed air outlet including an outlet panel extending in a fixed manner from the leading edge panel into the ambient flow, such that a rearward facing outlet opening is formed between the leading edge panel and a rear edge of the outlet panel.

A stall trigger system is disclosed having an aircraft wing tip or aircraft wing tip device, a plurality of sets of stall triggers distributed along a span of the aircraft wing tip or aircraft wing tip device. Each set of stall triggers comprises one or more stall triggers which can be activated to trigger local separation of air flow over the aircraft wing tip or aircraft wing tip device, and each set of stall triggers has a different activation threshold. A control system configured to monitor a parameter, and activate each set of stall triggers in response to the parameter reaching its respective activation threshold.

A stall trigger system is disclosed having an aircraft wing tip or aircraft wing tip device, a plurality of sets of stall triggers distributed along a span of the aircraft wing tip or aircraft wing tip device. Each set of stall triggers comprises one or more stall triggers which can be activated to trigger local separation of air flow over the aircraft wing tip or aircraft wing tip device, and each set of stall triggers has a different activation threshold. A control system configured to monitor a parameter, and activate each set of stall triggers in response to the parameter reaching its respective activation threshold.

An aircraft (1) including a fixed wing (7) and a wing tip device (9) moveably mounted thereon. The wing tip device (9) is movable from a load-alleviating configuration to a flight configuration. The wing tip device includes an airflow channel (88) extending between respective apertures (83, 84) on the upper surface and lower surface of the wing tip device. The channel (88) is configurable between an open state in which air can flow through the channel and a closed state in which the airflow through the channel (88), via the apertures (83, 84), is blocked. The channel (88) is configured such that when the wing tip device (9) is in the load-alleviating configuration and the channel (88) is in the open state, the aerodynamic loading on the wing tip device in flight urges the wing tip device towards the flight configuration.

An aircraft (1) including a fixed wing (7) and a wing tip device (9) moveably mounted thereon. The wing tip device (9) is movable from a load-alleviating configuration to a flight configuration. The wing tip device includes an airflow channel (88) extending between respective apertures (83, 84) on the upper surface and lower surface of the wing tip device. The channel (88) is configurable between an open state in which air can flow through the channel and a closed state in which the airflow through the channel (88), via the apertures (83, 84), is blocked. The channel (88) is configured such that when the wing tip device (9) is in the load-alleviating configuration and the channel (88) is in the open state, the aerodynamic loading on the wing tip device in flight urges the wing tip device towards the flight configuration.

A flow guide body for an aircraft includes a main body having an outer aerodynamic surface having a plurality of outlet openings, and flow control devices, each having an inlet, an interaction chamber, a first outlet and a second outlet. A first control inlet is connected to the interaction chamber at the first side of the chamber axis. The outlets are each connected to outlet openings in the aerodynamic surface. Each outlet has a control outlet. A second flow control device is arranged such that one outlet is connected with the inlet of the first flow control device. One of the control outlets of the first flow control device is connected to the first control inlet of the first flow control device, and the other of the control outlets of the first flow control device is connected to the first control inlet of the second flow control device.

A flow guide body for an aircraft includes a main body having an outer aerodynamic surface having a plurality of outlet openings, and flow control devices, each having an inlet, an interaction chamber, a first outlet and a second outlet. A first control inlet is connected to the interaction chamber at the first side of the chamber axis. The outlets are each connected to outlet openings in the aerodynamic surface. Each outlet has a control outlet. A second flow control device is arranged such that one outlet is connected with the inlet of the first flow control device. One of the control outlets of the first flow control device is connected to the first control inlet of the first flow control device, and the other of the control outlets of the first flow control device is connected to the first control inlet of the second flow control device.

According to the present disclosure there is provided an arrangement for influencing liquid flow, the arrangement comprising: a first section selectively configurable to provide a vortex generator surface to induce vortices in the liquid flow. The arrangement further comprises a second section, wherein the first section and second section are movable relative to one another to provide the vortex generator surface.