The unsteady flow around a pitching helicopter main rotor blade airfoil, the EDI-M109, was experimentally investigated at conditions similar to those existing on a retreating rotor blade in forward flight. High-speed pressure measurements and hot film anemometry were used to investigate the unsteady transition characteristics of the airfoil. Results are presented for dynamic test points with attached flow, light dynamic stall, and deep dynamic stall at M = 0.3, Re = 1.8 × 106, and f = 6.6 Hz. The results include the discussion of the periodicity of the hot film signals for different flow states. The transition process of the pitching airfoil is analyzed, and the significance of the intermittent region is described. A time delay between the transition and the model motion is discussed, and a linear relationship between the transition position and time is observed. The influences of the pitching amplitude on the transition characteristics are discussed, and the flow separation initiating dynamic stall is analyzed.


    Access

    Access via TIB

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Experimental Investigation of Unsteady Transition on a Pitching Rotor Blade Airfoil


    Additional title:

    Experimentelle Untersuchung des instationären laminar-turbulenten Übergangs der Strömung an einem Rotorblatt eines Hubschraubers


    Contributors:
    Richter, K. (author) / Koch, S. (author) / Gardner, A.D. (author) / Mai, H. (author) / Klein, A. (author) / Rohardt, C.H. (author)

    Published in:

    Journal of the American Helicopter Society ; 59 , 1 ; 012001/1-012001/12


    Publication date :

    2014


    Size :

    12 Seiten, Bilder, 16 Quellen




    Type of media :

    Article (Journal)


    Type of material :

    Print


    Language :

    English




    Airfoil for rotor blade with reduced pitching moment

    BAGAI ASHISH | European Patent Office | 2016

    Free access

    AIRFOIL FOR ROTOR BLADE WITH REDUCED PITCHING MOMENT

    BAGAI ASHISH | European Patent Office | 2016

    Free access

    INFLUENCE OF OSCILLATION AMPLITUDE AND MACH NUMBER ON THE UNSTEADY TRANSITION ON A PITCHING ROTOR BLADE AIRFOIL

    Richter, K. / Koch, S. / Gardner, A.D. et al. | British Library Conference Proceedings | 2013


    GenHel Rotor Blade Airfoil Unsteady Aerodynamic Model

    Garelick, M. / Vertical Flight Technical Society | British Library Conference Proceedings | 2012


    Unsteady Criteria for Rotor Blade Airfoil Design

    Klein, A. / Richter, K. / Altmikus, A. et al. | British Library Conference Proceedings | 2009