Patent ID: 8272594
Filing Date: 2012-09-25
Classification: B64C,Y02T

Abstract:
1. A method of providing an aircraft having a fuselage, and a wing configured for extensive laminar flow at design cruise conditions, the method characterized by the steps: a) providing wing biconvex-type airfoils having values of thickness, chord and shape along the wing span which provide substantially optimal aircraft range at said design cruise conditions, considering the influences of wing drag and wing weight, b) providing wing leading edges, which are configured to effect laminar flow, and c) providing fuselage and wing contours which, in combination, produce reduced total wave drag and produce extensive areas of laminar boundary layer flow on the wing, d) providing wing sweep angularity that facilitates provision of said a), b) and c), e) and said provided airfoils have at span locations a ratio t/c of maximum thickness, t, to chord, c, at such locations, said t/c ratio having value along the span outboard of a zone of fuselage influence, such that the average of said ratio, is given by, where M=supersonic design cruise Mach number, f) and wherein for values of design cruise Mach number M between 1.3 and 2.8, the corresponding maximum values of t/c are approximately linearly proportional to maximum values between 0.027 and 0.040, where t is airfoil thickness and c is airfoil chord along the wing span outbound of said zone of fuselage influence.