LOW-SPEED LONGITUDINAL AERODYNAMIC CHARACTERISTICS ASSOCIATED WITH A SERIES OF LOW-ASPECT-RATIO WINGS HAVING VARIATIONS IN LEADING-EDGE CONTOUR

摘要

An investigation has been conducted at various Reynolds numbers and low subsonic speeds to determine the longitudinal aerodynamic characteristics associated with a series of low-aspect-ratio wings having variations in leading-edge contours. The planforms included a highly swept triangular wing, a rectangular wing, and intermediate N wings including planforms having elliptic and parabolic leading-edge contours, all having an aspect ratio of 1.33. The effects of changing aspect ratio for a given leading-edge contour were investigated for two of the wings presented;also included are the longitudinal char¬acteristics associated with various fuselage sizes. An effort has been made to estimate the lift variation with angle of attack for the wing planforms of the present investigation. Improvements in the lifting capabilities at low subsonic speeds associated with a basic triangular planform of low aspect ratio are possible by slight alterations in leading-edge design, which should still conform to possible design requirements at hypersonic speeds. These changes in planform resulted in increases in lift-curve slope, lift at high angles of attack, and in the maximum untrimmed lift-drag ratio, provided the fuselage was sufficiently small. The longitudinal stability characteristics of the majority of planforms indicate more desirable stability characteristics at high lifts than either a trian¬gular wing or rectangular wing of the same aspect ratio.