摘要 :
Stability and control characteristics of variable sweep airplane configuration capable of low-level supersonic attack - outer wing swept 75 degrees and 108 degrees
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 differe...
展开
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.
Wing 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.
收起
摘要 :
Results computed by a finite-difference, relaxation algorithm are presented for the supercritical flow (M∞ = 0.825) about the C-141 airplane wing, which has sweep, taper, and twist. Comparisons with both wind-tunnel and flight da...
展开
Results computed by a finite-difference, relaxation algorithm are presented for the supercritical flow (M∞ = 0.825) about the C-141 airplane wing, which has sweep, taper, and twist. Comparisons with both wind-tunnel and flight data indicate that computed solutions of the classical transonic small disturbance equation can accurately simulate high Reynolds number flows when the shock sweep angle is small. It is also shown that this equation poorly approximates the complete potential equation when embedded shock waves are swept at angles greater than about 15°. Hence, a more consistent small disturbance equation is derived for use in more general cases.
收起
摘要 :
A three-dimensional investigation of straight-sided-profile plain ailerons on a wing with 30 degrees and 45 degrees of sweepback and sweepforward was made in a high-speed wind tunnel for aileron deflections from -10 degrees to 10 ...
展开
A three-dimensional investigation of straight-sided-profile plain ailerons on a wing with 30 degrees and 45 degrees of sweepback and sweepforward was made in a high-speed wind tunnel for aileron deflections from -10 degrees to 10 degrees and at Mach numbers from 0.60 to 0.96. Wing configurations of 30 degrees generally reduced the severity of the large changes in rolling-moment and aileron hinge-moment coefficients experienced by the upswept wing configurations as the result of compression shock and extended to higher Mach numbers the speeds at which such changes occurred.
收起
