A swept flat plate model with an imposed pressure gradient was experimentally investigated in a low-speed flow to determine the effect of a backward-facing step on transition in a stationary crossflow–dominated flow. Detailed hotwire measurements of boundary-layer flow were performed to investigate the upstream shift in transition due to a step height of 49% of the local unperturbed boundary-layer thickness. Increasing the initial stationary crossflow amplitude caused an upstream movement of the transition front for the backward-facing step case. The step caused a local increase in the growth of the stationary crossflow instabilities, but the stationary crossflow amplitude at transition was sufficiently low ( < 0.04 U e ) so that stationary crossflow was not solely responsible for transition. The unsteady velocity spectra downstream of the step were rich with unsteady disturbances in the 80- to 1500-Hz range. Three distinct families of disturbances were identified based on phase speed and wave angle, namely, a highly oblique disturbance (possibly traveling-crossflow-like), a Tollmien–Schlichting-wave-like disturbance, and a shear-layer instability. The stationary crossflow disturbances caused a modulation of the unsteady disturbances, resulting in spatially concentrated peaks in unsteady disturbance amplitude. This modulation of the unsteady disturbances is believed to be the reason for the upstream movement of the transition front with increasing stationary crossflow amplitude.


    Zugriff

    Zugriff prüfen

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    Interaction of a Backward-Facing Step and Crossflow Instabilities in Boundary-Layer Transition


    Beteiligte:

    Erschienen in:

    AIAA Journal ; 56 , 2 ; 497-509


    Erscheinungsdatum :

    01.02.2018




    Medientyp :

    Aufsatz (Konferenz) , Aufsatz (Zeitschrift)


    Format :

    Elektronische Ressource


    Sprache :

    Englisch




    The Interaction of a Backward-Facing Step and Crossflow Instabilities in Boundary-Layer Transition

    Eppink, Jenna L. / Wlezien, Richard / King, Rudolph A. et al. | AIAA | 2015


    The Interaction of a Backward-Facing Step and Crossflow Instabilities in Boundary-Layer Transition (AIAA 2015-0273)

    Eppink, Jenna L. / Wlezien, Richard / King, Rudolph A. et al. | British Library Conference Proceedings | 2015


    Modeling the Effects of a Backward-Facing Step on Boundary-Layer Transition

    N. Hildebrand / P. V. Mysore / M. M. Choudhari et al. | NTIS | 2021


    MODELING THE EFFECTS OF A BACKWARD-FACING STEP ON BOUNDARY-LAYER TRANSITION

    Hildebrand, Nathaniel J. / Mysore, Preethi V. / Choudhari, Meelan M. et al. | TIBKAT | 2021


    Influence of a Backward-Facing Step on Swept-Wing Boundary-Layer Transition

    Eppink, Jenna L. / Wlezien, Richard W. / King, Rudolph A. et al. | AIAA | 2019