Effect of linear spanwise variations of twist and circular-arc camber on low-speed static stability, rolling, and yawing characteristics of a 45 degree sweptback wing of aspect ratio 4 and taper ratio 0.6

Abstract : An investigation at low scale has been made in the Langley stab unity tunnel in order to determine the effect of linear spanwise variations of twist and circular-arc camber on the low-speed aerodynamic characteristics and static-stability and rotary-stability (rolling and yawing) derivatives of a wing of aspect ratio 4, taper ratio 0.6, and with 45 deg sweepback of the quarter-chord line. Results of the investigation indicate that twist or camber produced only small changes in the maximum lift coefficient. A combination of camber and twist was more effective than twist alone in providing an increase in the maximum lift-to-drag ratio in the moderate lift-coefficient range for the wings investigated. The variation of static longitudinal stability through the lift-coefficient range was less for the twisted wing than for the twisted and cambered or plane wing. A combination of twist and camber generally extended the initial linear range of several of the static- and rotary-stability derivatives to a higher lift coefficient and, although these effects were small, higher Reynolds numbers may result in larger effects.