Passive flow control devices for a fully turbulent backward-facing step flow were investigated experimentally with particle image velocimetry and dynamic pressure transducers in the Trisonic Wind Tunnel Munich at Mach numbers of 0.80 and 2.00, as well as at Reynolds numbers of R e h = 180 , 000 and 210,000, respectively. The results showed that these flow control devices, which are comprised of circular and square convoluted trailing edges on the backward-facing step, were a far more effective alternative to active flow control. The mean reattachment length was reduced by over 80% for the most effective configuration: so-called square lobes with a protrusion height of 0.4 step heights. This geometry also reduced the root mean square of the pressure fluctuations experienced by the reattachment surface by nearly 50% in transonic conditions. It was shown that the harmful step mode was weakened by forcing streamwise vorticity onto the flow through the presence of the lobes. The square lobes were more effective in diffusing this mode when compared to the circular lobes. Similarly, with increasing lobe sizes, the effectiveness of the flow control devices increased. Thus, a simple passive solution was determined for reducing the buffeting effects experienced by space launchers in transonic flight, for instance.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Passive Flow Control for Reduced Load Dynamics Aft of a Backward-Facing Step


    Contributors:

    Published in:

    AIAA Journal ; 57 , 1 ; 120-131


    Publication date :

    2019-01-01




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English




    Passive Flow Control on Backward Facing Step

    Findanis, Nicholas | AIAA | 2018


    Passive Load Control in Backward-Facing Step Flow by Using Chevrons

    Nilsson, Johan / Szász, Robert-Zoltán / Austrell, Per-Erik et al. | Springer Verlag | 2016


    Passive Flow Control on Backward Facing Step (AIAA 2018-3088)

    Findanis, Nicholas | British Library Conference Proceedings | 2018


    Active control of a backward-facing step flow

    Marrot, Franck / Simon, Franck / Gajan, Pierre et al. | AIAA | 2000


    Flow Control Downstream of a Backward Facing Step

    Spazzini, P.G. / Uso, G.I. / Zurlo, N. et al. | British Library Conference Proceedings | 2000