SMALL LEADING-EDGE FLAP FOR POST-STALL FLOW CONTROL ON A 45-DEG DELTA WING

摘要

The characteristics of rolling moment in a 45-deg delta wing with a leading-edge flap were studied to examine its effects in pre- and poststall high angle-of-attack regimes, where conventional control surfaces are ineffective. A small Sap was employed to control the Sow, which was placed on the round leading-edge of the delta wing from 10% to 75% chord with a height of 2 mm. The wind-tunnel experiments were carried out for static aerodynamic force measurements and flow visualization. In the pre-stall moderate angle-of-attack regime, it is observed that the single flap can produce about ±0.01 of rolling moment coefficient, which is sufficient for flight control. On the other hand, in the post-stall high angle-of-attack regime, its rolling moment characteristics are quite nonlinear and complex. The flap can basically reduce the unsteady moment by interfering with the development of an leadingedge vortex, or promoting the flow attachment to the wing surface.