GB856507A - Improvements in supersonic airfoil - Google Patents

Abstract

856,507. Aircraft wings and propulsion units. GENERAL ELECTRIC CO. April 21, 1959, No. 13537/59. Class 4. [Also in Group XXVI] A wing for a supersonic aircraft comprises vertically-spaced upper and lower portions 5 and 4 which define between them a chamber 7 constituting a ram-jet propulsion unit. The upper surface of portion 5 is planar and inclined as shown to the horizontal 10 in flight and the lower surface of portion 5 is substantially parallel thereto, the two portions being connected by faired struts 6. The lower surface of portion 5 commences at a beak 8 and extends rearwardly in a concave surface 11, which may be continuous as shown or formed by a plurality of discontinuous flat portions, to form with the upper surface of portion 4 a throat referred to as a supersonic pressure chamber which extends into an enlarged combustion chamber 7 provided with a propulsion nozzle 30. The profile of surface 11 is selected to generate an infinite number of shock waves 14, 15, 16, 17 which will intersect a principal shock wave 9 generated at beak 8 to increase its magnitude and deflect it from the leading edge 17 of the portion 4. The pressure rise beneath surface 11 resulting from the shock waves provides a lifting effect on the aerofoil. A further shock wave 20 from leading edge 17 results in reflections 21-23 and a standing wave 24. This results in a pressure increase within chamber 7. The Figure is a chordwise cross-section through an aircraft wing and the duct may extend throughout the span. Ducts 31 and 32 are provided to bleed boundary layer air from the lower leading surfaces of portions 5 and 4 and such air may be used to cool the walls of the combustion chamber.