回転する前縁部によるデルタ翼の揚力増加

抄録

The subsonic flow for a 45 deg-swept delta wing was numerically simulated to see the effects of rotational leading edges on aerodynamic forces. In the present study, part of the cylindrical leading edge can be rotated which extends from x=0.25C to 0.90 C. The computation has been performed at an angle of attack of 20 deg and a Reynolds number of 2.0×10⁴ based on the maximum wing root chord. Under these conditions, the flow is fully separated from the wing surface in the case without leading edge rotation, so that no suction peaks due to leading edge vortices appear over the upper surface of the wing. Consequently, the delta wing will not have an effective vortical lift. In the case of steady rotation, leading edge vortices were produced on the wing in the early stage. However, a gradual drop in lift coefficient occurred as a result of the diffusion of these vortices. By contrast, in the case of unsteady rotation, a pair of leading edge vortices was maintained, so that a higher lift was produced. Consequently, the lift coefficient became more than 40% higher than that of the plain delta wing.