Vortex Flow Visualization of a Yawed Delta Wing with Leading Edge Extension

The development and interaction of vortices over a yawed delta wing with leading-edge extension (LEX) was investigated through off-surface flow visualization using micro water droplets and a laser beam sheet. Angles of attack of 12, 16, 20, and 24 deg were tested at sideslip angles of 0, -5, and -10 deg. The flow Reynolds number based on the main-wing chord was 1.82 × 10 5 . The wing vortex and the LEX vortex coiled around each other while maintaining comparable strength and identity at a zero sideslip. The increase of angle of attack intensified the coiling and shifted the cores of the wing and LEX vortices inboard and upward. By sideslip, the coiling, the merging and, the diffusion of the wing and LEX vortices increased on the windward side, whereas they became delayed significantly on the leeward side. Also the migration behavior of vortices on the windward and leeward sides of the wing changed considerably