Turbulent boundary layers have been manipulated successfully using passive devices called BLADES (boundary-layer alteration devices) leading to net drag reduction. Measurements of various turbulence quantities including intermittency have led to the identification of some of the mechanisms involved in skin-friction reduction. Velocity and vorticity fluctuations associated with oncoming large scales are inhibited significantly by the manipulator blades and the vorticity shed in their wake. The manipulated boundary layers exhibit a reduced intermittency in the outer part of the layer. The effects of manipulation relax with downstream distance and the boundary layer returns toward normal conditions after 100 or 150 boundary-layer thicknesses.


    Zugriff

    Zugriff über TIB

    Verfügbarkeit in meiner Bibliothek prüfen


    Exportieren, teilen und zitieren



    Titel :

    Mechanisms leading to net drag reduction in manipulated turbulent boundary layers


    Beteiligte:
    Guezennec, Y. G. (Autor:in) / Nagib, H. M. (Autor:in)

    Erschienen in:

    Erscheinungsdatum :

    01.02.1990



    Medientyp :

    Sonstige


    Format :

    Keine Angabe


    Sprache :

    Englisch





    A drag reduction method for turbulent boundary layers

    GAD-EL-HAK, MOHAMED / BLACKWELDER, RON | AIAA | 1987


    Drag reduction in turbulent boundary layers using ribbons

    BERTELRUD, A. / TRUONG, T. / AVELLAN, F. | AIAA | 1982