THE EFFECT OF BODY CONTOURING ON THE LONGITUDINAL CHARACTERISTICS AT MACH NUMBERS UP TO 0.92 OF A WING-FUSELAGE-TALL AND SEVERAL WING-FUSELAGE COMBINATIONS HAVING SWEPTBACK WINGS OF RELATIVELY HIGH ASPECT RATIO

摘要

An investigation has been conducted to determine the effect of a Kuchemann type fuselage modification designed to reduce the interference velocities at the wing-fuselage junctures on the longitudinal character¬istics of a wing-fuselage-tail combination and several wing-fuselage combinations. The wing-fuselage-tail combination had a 40° sweptback wing with NACA 64A thickness distribution and the wing-fuselage combina¬tions used a wing with NACA four-digit thickness distribution which was swept back 40°, 45°, or 50°. The tests were made through an angle-of-attack range at Mach numbers varying from 0.60 to 0.92 at a Reynolds number of 2 million.nThe fuselage modification for the combinations with 40° of sweepback reduced the drag and increased the lift-drag ratios for moderate lift coefficients at high subsonic speeds. Drag reductions of as much as 18 percent were obtained for the wing-fuselage-tail combination with the 64A thickness distribution and as much as 10 percent for the four-digit wing-fuselage combination. For the combinations with 40° of sweepback, the fuselage modification increased the lift-curve slopes slightly at high subsonic speeds, but had little or no effect on longitudinal stability at most Mach numbers. With the four-digit wings having 45° and 50° of sweepback the effects of the fuselage modification were small and inconsistent at the test Mach numbers.