A COMPARISON OF THE EXPERIMENTAL AERODYNAMIC CHARACTERISTICS OF AN OBLIQUE WING WITH THOSE OF A SWEPT WING

摘要

Force and moment characteristics were measured for two trapezoidal oblique wings and a conventional swept wing mounted on a body of revolution at Mach numbers from 0.2S to 2.0. Both oblique wings had the same planform, but differed in profile and flexibility. One of the oblique wings was made of solid steel and had a maximum thickness-to-chord ratio of 4 percent. The other wing was built up by taking an aluminum wing (having a geometrically similar profile and planform to that of the steel wing) and adding epoxy material to the upper surface to increase the maximum thickness-to-chord ratio to 8.2 percent. The aspect ratio for both oblique wings when swept 45°, and for the swept wing with 45° of sweep was 4.1. Data were obtained at unit Reynolds numbers ranging from 3.3 to 8.2 million per meter in order to vary the dynamic pressure and to explore any flexibility effects. These data were compared with previously obtained data (ref. 5) on the aluminum wing before it was built up with epoxy.nWing flexibility designed into the aluminum and built-up aluminum oblique wings increased the range of lift coefficients from 0.30 to 0.70 over which the pitching-moment curves were linear. However, flexibility did not improve the linearity of the rolling-moment curves and produced sizable side forces. At a Mach number of 0.95, the trapezoidal oblique wing had little or no improvement in the lift/drag ratios over those for a conventional swept wing of the same aspect ratio, sweep, and profile, probably because of the thinness of the wing profile. Thicker, highly cambered profiles previously investigated on oblique wings showed considerable improvement in the maximum lift/drag ratios over those for a conventional swept wing with the same profiles throughout a Mach number range from 0.6 to 1.2.