Tey Shen  Xi, Noorfazreena Mohammad  Kamaruddin, Zulfaa  Mohamed-Kassim, 
    Flow Visualization Study of Wing-Tip Vortex for a Wing with Cavity,
    Journal of Engineering and Applied Sciences,
    Volume 12,Issue 15,
    2017,
    Pages 3813-3817,
    ISSN 1816-949x,
    jeasci.2017.3813.3817,
    (https://makhillpublications.co/view-article.php?doi=jeasci.2017.3813.3817)
    Abstract: This study investigates the flow structures of wing-tip vortex for a wing model with cavity variation at low Reynolds number. The flow structures over a triple-cavities wing model with an aspect ratio of 2 were investigated at angle of attack 0°, 5°, 10° and 15° by using smoke wire flow visualization technique. A non-cavity flat plate model was employed as a reference for comparison of flow structures between the two wing models. The flow visualization results revealed that as the angle of attack increased the wing-tip vortices were increased in strength and more maturely developed with an inboard circulation over the wing-tip. The downwash effect of the wing-tip vortex also resulted in vortex trapping in the cavity of the wing model which rotated clockwise before exiting the cavity. The experiment also revealed that the vortex is trapped and occurred more significantly at higher angle of attack which could potentially lead to the reduction of induced drag.
    Keywords: Wing-tip vortex;cavity;smoke visualization technique;vortex trapping;wing model