The current study was conducted to understand flowfield unsteadiness associated with static stall hysteresis on a NACA 0012 airfoil at R e c = 1.0 × 10 6 . Unsteady pressure measurements were acquired to evaluate the performance of the airfoil, and the presence of a hysteresis loop was identified in the vicinity of the airfoil C l , max . At poststall angles of attack, two fundamentally different flow regimes were observed between the upstroke and downstroke branches of the hysteresis loop. A Fourier analysis of the surface pressure distributions was used to attribute the flowfield unsteadiness to a low-frequency, high-amplitude oscillation in the flow near the leading edge, along with a regular bluff-body shedding frequency across the separated region of the airfoil. The low-frequency oscillations were observed to be more dominant for the upstroke branch, whereas the bluff-body shedding process was more dominant in the downstroke branch. Time-resolved particle image velocimetry data were acquired across the airfoil to qualitatively and quantitatively describe the low-frequency unsteadiness in the flow. These data were used to link the oscillations across the leading edge during the upstroke to a quasi-periodic surging of the flow, along with an advancement and retreating of the separation location across the surface.


    Zugriff

    Zugriff prüfen

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    Poststall Hysteresis and Flowfield Unsteadiness on a NACA 0012 Airfoil


    Beteiligte:

    Erschienen in:

    AIAA Journal ; 56 , 7 ; 2528-2539


    Erscheinungsdatum :

    2018-03-28


    Format / Umfang :

    12 pages




    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Elektronische Ressource


    Sprache :

    Englisch




    Post-Stall Hysteresis and Flow Field Unsteadiness on an NACA 0012 Airfoil

    Hristov, Georgi / Ansell, Phillip J. | AIAA | 2017


    Post-Stall Hysteresis and Flow Field Unsteadiness on an NACA 0012 Airfoil (AIAA 2017-0997)

    Hristov, Georgi / Ansell, Phillip J. | British Library Conference Proceedings | 2017


    Numerical Simulation of a Pitching NACA 0012 Airfoil

    Pechloff, A. / International Council of the Aeronautical Sciences | British Library Conference Proceedings | 2000


    Heat transfer measurements from a smooth NACA 0012 airfoil

    POINSATTE, PHILIP E. / VAN FOSSEN / G. J. et al. | AIAA | 1991


    Computation of dynamic stall of a NACA-0012 airfoil

    SHIDA, YOSHIFUMI / KUWAHARA, KUNIO / TAKAMI, HIDEO et al. | AIAA | 1987