摘要:
An aerofoil has a body (14), and at least one flow control device, the flow control device including a passage (22) within the body (14) of the aerofoil, and a passage outlet (21) at an upper aerofoil surface (18) of the aerofoil, whereby in use, air from the passage (22) passes through the passage outlet (21) to affect airflow over the upper surface (18) of the aerofoil over at least a range of incidence angles, wherein the passage outlet (21) is provided by an outlet fitting (24) which is secured relative to the upper surface (18) of the aerofoil, the outlet fitting including a surface part (25) which lies contiguously with the surrounding upper aerofoil surface (18) so there is no or only a minimal discontinuity where the surface part (25) and the surrounding upper aerofoil surface (18) interface, the surface part (25) of the fitting further including an opening (21) which communicates with the passage (22) within the body (14) of the aerofoil.
摘要:
An aircraft includes an impeller (12;T), an engine (10), and a transmission (14) to transmit drive from the engine (10) to the impeller (12;T), and means (25; 35,36) to use engine power to rotate a mechanical energy accumulator means (28; 28a), and means (25; 35,36) to recover power from the inertia of the rotating mechanical energy accumulator means (28; 28a) and to transmit the recovered power to the impeller (12;T).
摘要:
A propeller (10 a ) comprising a plurality of propeller blades (9 a ) each having a root end (11 a ) attached to the central propeller disc or hub (12 a ), an intermediate portion (13 a ) extending from the root end (11 a ) and having a generally aerofoil cross section extending chordwise between a leading edge (14 a ) and a trailing edge (15 a) , and the blade (9 a ) having a tip (19) at an end of the intermediate portion (13 a ) remote from the root end (11 a ), the tip (19) having a leading edge portion (20) extending forwardly from a junction (21) with the leading edge (14 a ) of the intermediate portion (13 a ) thus to provide a discontinuity or notch (25) in the leading edge (14 a ) of the blade (9 a ) at the junction (21).
摘要:
A cowling assembly (10) for a vehicle comprises a general external surface (11) having secured to or adjacent thereto, an elongate lightning diverter element (14-19) which, at least when subjected to a high electric field, is electrically conductive, wherein a portion (16 a - 19 a ) of the diverter element is arranged to project from the general external surface (11).
摘要:
A static vent unit (11) for use e.g. on the side of an aircraft (A) and which in operation is subjected to airflow from any direction within a wide airflow incidence range comprises a generally flat plate (12) having an outer surface for fitment generally to flush to an outer surface (14) of the aircraft (A), a vent port (15) through the plate (12) for connection during operation to a static vent line (16) in the aircraft (A), and a bulge (19) on the plate outer surface surrounding at least part of a circumference of the vent port (15) and having in cross section a convex curved upper surface extending radially inwardly from an outer edge (22) on the plate (17) to an inner edger (23) on the plate (17) adjacent the circumference of the vent port (15) and adapted during operation to promote attachment of an airflow from within at least part of the airflow incidence range to its surface and direct the airflow into the vicinity of the vent port (15) to provide a compensating increase in ambient pressure at the vent port.
摘要:
A rotary blade (10,19) includes a fixed boundary layer control device (15,25,37) extending spanwise on a lower surface (14,23) adjacent the trailing edge (12,21) to improve the lift/thrust characteristics of the blade especially at positive incidence angles. It was discovered that expected detrimental effects at zero/negative incidence did not materialise and the reasons are identified. Such blades are particularly useful for helicopter sustaining and anti-torque rotors.
摘要:
A flexible beam type helicopter rotor includes restraining means (24) outboard of a snubber means (17) and connected between the flexible beam (13) and a torque tube (16) to increase the stiffness of the rotor in the lead/lag plane as applied pitch is increased.