Sound absorbers and airframe components comprising such sound absorbers are disclosed. In one embodiment, an airframe component comprises an aerodynamic surface (48) and a sound absorber (38). The sound absorber (38) comprises a perforated panel (40) having a front side exposed to an ambient environment outside of the airframe component and an opposite back side. The panel (40) comprises perforations extending through a thickness of the panel for permitting passage of sound waves therethrough. The sound absorber (38) also comprises a boundary surface spaced apart from the perforated panel. The boundary surface and the back side of the perforated panel (40) at least partially define a cavity in the airframe component for attenuating some of the sound waves entering the cavity via the perforations in the perforated panel (40).

A leading edge structure (1) for a flow control system of an aircraft (101) including a double-walled leading edge panel (3) surrounding a plenum (7). The leading edge panel (3) has a first side portion (11) extending to a first attachment end (17), a second side portion (13) extending to a second attachment end (19), an inner wall element (21) facing the plenum (7), an outer wall element (23) for contact with an ambient flow (25), a core assembly (97). The outer wall element (23) includes micro pores (31) forming a fluid connection between the core assembly (97) and the ambient flow (25). The inner wall element (21) includes openings (33) forming a fluid connection between the core assembly (97) and the plenum (7). The outer wall element (23) extends from the first attachment end (17) to the second attachment end (19).

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.

A leading edge structure (11) for a flow control system of an aircraft (1) including a leading edge panel (13) surrounding surrounds a plenum (17) which extends in a span direction (19), wherein the leading edge panel (13) has a first side portion (21) extending from a leading edge point (23) to a first attachment end (25), wherein the leading edge panel (13) has a second side portion (27) opposite the first side portion (21), extending from the leading edge point (23) to a second attachment end (29), wherein the leading edge panel (13) comprises an inner surface (33) facing the plenum (17) and an outer surface (37) in contact with an ambient flow (39), and wherein the leading edge panel (13) comprises a plurality of micro pores (45) forming a fluid connection between the plenum (17) and the ambient flow (39).

An aircraft structure, for example a wing, including a skin. The skin has an external surface, on an outer face of the skin. The skin has an internal surface, located opposite the external surface on an inner face of the skin. The aircraft structure includes a laminar flow control system including a compressor. The aircraft structure is so arranged that the exhaust air from the compressor is directed onto the internal surface of the skin of the aircraft structure, for example thus providing hot exhaust air which function as an ice protection system (whether by de-icing or anti-icing). A method of providing ice protection on a surface of an aircraft using exhaust air from a laminar flow control compressor is also described.

This disclosure relates to the manufacturing of a leading edge section with hybrid laminar flow control for an aircraft. A manufacturing method involves: providing an outer hood, a plurality of elongated modules, first and second C-shaped profiles having comprising cavities, and an inner mandrel; assembling an injection molding tool by placing each profile on each end of the inner mandrel, arranging a first extreme of each elongated module in one cavity of the first profile and a second extreme of the module in another cavity of the second profile, both cavities positioned in the same radial direction; and placing the hood on first and second profiles to close the tool. Further, the injection molding tool is closed and filled with an injection compound comprising thermoplastic and short-fiber. Finally, the compound is hardened and demolded.

An aerodynamic body operable to both promote laminar flow and satisfy structural requirements is disclosed. A perforated panel skin comprises an inner surface and an outer surface of the aerodynamic body. At least one hollow member is coupled to the inner surface and is operable to suction air from the outer surface and through the perforated panel skin. The at least one hollow member is oriented in a substantially chord-wise direction relative to an airflow over the aerodynamic body.

A leading edge structure (13) for a flow control system of an aircraft (1), including a double-walled leading edge panel having an inner wall element (45) and an outer wall element (47). Between the inner and outer wall elements (45, 47) are elongate stiffeners (49) spaced apart from one another. And, between adjacent stiffeners (49) are a hollow chamber (51). The outer wall element (47) includes micro pores (53). The inner wall element (45) includes passages (55) forming a fluid connection between the hollow chambers (51) and a vacuum system (15). An ice protection system in the stiffeners (49) includes hot air ducts (57) configured for connection to a hot air system (17), and the stiffeners (49) include hot air openings (59) forming a fluid connection between the hot air ducts (57) and the hollow chambers (51).

A stealth craft's aerodynamics and flight stability are improved with the use of a multi-faceted dihedral planform. The stealth craft includes a multi-faceted dihedral planform extending in a direction from a front to a rear of a craft (or wing) and defined by a first set of facets followed by a second set of facets. In an exemplary embodiment, the first and second sets of facets have an angle of incline that is ascending and descending, respectively, with respect to the direction of the planform. Selected ones of the first and second sets of facets are configured with insufflation slots for improving aerodynamics and stability, the insufflation slots extending spanwise in a direction transverse to the direction of the planform and provided to insufflate a fluid to form a cushion of air along the multi-faceted dihedral planform for improving aerodynamics and stability.

Within examples, systems for enhanced performance blades for rotor craft are provided and methods for operation. An example system for a rotary device is provided comprising a rotor blade coupled to a rotor hub. The system also comprises an air channel disposed within the rotor blade, where the air channel is sealed proximate to a distal end of the rotor blade. The system also comprises an inlet positioned at a proximal end of the rotor blade, where the inlet is in fluid communication with the air channel. The system also comprises a plurality of outlets positioned along the rotor blade, where each of the plurality of outlets are in fluid communication with the air channel.