AbstractVortex control concepts employed for slender and nonslender delta wings were reviewed. Important aspects of flow control include flow separation, vortex formation, flow reattachment, vortex breakdown, and vortex instabilities. The occurrence and relative importance of these phenomena strongly depend on the wing sweep angle. Various flow control methods were discussed: multiple vortices, control surfaces, blowing and suction, low-frequency and high-frequency excitation, feedback control, passive control with wing flexibility, and plasma actuators. For slender delta wings, control of vortex breakdown is achieved by modifications to swirl level and external pressure gradient acting on the vortex core. Effects of flow control methods on these two parameters were discussed, and their effectiveness was compared whenever possible. With the high-frequency excitation of the separated shear layer, reattachment and lift enhancement in the post-stall region is observed, which is orders of magnitude more effective than steady blowing. This effect is more pronounced for nonslender wings. Re-formation of vortices is possible with sufficient amplitude of forcing at the optimum frequency. Passive lift enhancement on flexible wings is due to the self-excited wing vibrations, which occur when the frequency of wing vibrations is close to the frequency of the shear layer instabilities, and promote flow reattachment.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Review of flow control mechanisms of leading-edge vortices


    Contributors:
    Gursul, I. (author) / Wang, Z. (author) / Vardaki, E. (author)

    Published in:

    Publication date :

    2007-01-01


    Size :

    25 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English



    Review of flow control mechanisms of leading-edge vortices

    Gursul, I. / Wang, Z. / Vardaki, E. | Tema Archive | 2006



    Review of Flow Control Mechanisms of Leading-Edge Vortices

    Gursul, I. / Wang, Z. / Vardaki, E. et al. | British Library Conference Proceedings | 2006


    Review of Flow Control Mechanisms of Leading-Edge Vortices

    Gursul, Ismet / Wang, Zhijin / Vardaki, Eleni | AIAA | 2006


    Flow measurements in leading edge vortices

    SFORZA, P. / STASI, W. / PAZIENZA, J. et al. | AIAA | 1977