MAXIMUM-LIFT CHARACTERISTICS OF A WING WITH THE LEADING EDGE SWEEPBACK DECREASING FROM 45° AT THE ROOT TO 20° AT THE TIP AT REYNOLDS NUMBERS FROM 2.4 x 106 TO 6.0 x 106

摘要

Results are presented of an investigation of the maximum—lift characteristics of a wing with the leading—edge sweepback decreasing from 45° at the root to 20° at the tip and having an aspect ratio of 4.12 and NACA 64A009 airfoil sections. The investigation was made for conditions of leading edge smooth and leading edge rough for the basic wing and for the wing with split flaps, leading-edge flaps, out-hoard slats, and combinations of these high—lift devices at Reynolds numbers from 2.4 X 106 to 6.0 X 106. The maximum lift coefficient at a Reynolds number of 4.84 x 106 is 0.86 for the basic wing, 1.30 with split flaps installed, 1.24 with full—span leading—edge flaps installed, and 1.66 for the combination of full—span leading—edge flaps and split flaps. A large amount of static longitudinal stability near maximum lift is indicated for all configurations except those with full—span leading—edge flaps where the stability is marginal. The full—span leading—edge flaps' provide a considerable increase in the lift—drag ratio at high angles of attack. The results obtained for the subject wing are comparable to those obtained for conventional sweptback wings of moderate sweepback.