Low-Speed Wind-Tunnel Tests on Two Thin Cranked Wings with 6o-deg Sweepback Inboard

摘要

Low-speed wind-tunnel tests have been made on two thin wings of aspect ratio 3 with 60-deg leading-edge sweep at the root. Both wings show large forward movements of the aerodynamic centre at moderate lift coefficient {CL = 0.5 to 0.7). This forward movement can be delayed to CL = 1.0 by full-span Kruger-type leading-edge flaps. The normal type of split flap with hinge-line parallel to the wing trailing edge gave a decrease in usable CL and better results were obtained with flaps with their hinge-line skewed to the wing trailing edge at a smaller angle of sweepback. With skewed split flaps and full-span nose flaps CL — 1.2 at a = 17| deg was reached on both wings with only small movements of the aerodynamic centre.