Aspects of Canard-Wing Vortices Interaction in Subsonic Flow

A series of subsonic wind tunnel tests was conducted on a canard-wing configuration to study the interaction of canard and wing vortices. Both the canard and the wing in the present experiments had equal sweep angles. The velocity contours were measured using a total-static rake at three chordwise positions at front, middle and rear parts of the wing in a plane perpendicular to the wing surface. The experiments were performed at various combinations of angle of attack and canard deflection angle. The results show a close relationship between the strength of the vortices and the outcome of their interaction. According to the present findings, when the wing strong vortex is exposed to the strong vortex of the canard, the result of this interaction would be a weaker vortex on the wing with a smaller size than the original two vortices, while a weak vortex on the canard when interacted with a strong vortex on the wing, amplifies it and results in a stronger vortex on the wing surface. This has also been shown to be true when a strong canard vortex interacts with a weak vortex on the wing. The result would again be a stronger vortex on the wing surface.