Abstract: The experimental results on the influences of oscillating leading edge vortex-flaps of triangular wing toward the vortex breakdown are presented in this paper. The results reveal that forced oscillations can delay the breakdown of concentrated vortices, and large reversed-flow regions which originally appears at the upper surface of the fixed wing at high angles of attack would be suppressed to some extent, depending on the oscillation frequencies. As a consequence, the influences can be optimized by selecting proper oscillation frequencies.

Key words: unsteady flow, delta wings, vortex flow, flow visual-ization