The effects of sound source location, Mach number and angle of attack on the shielding of a laser-induced sound source by a NACA 0012 airfoil are examined. The sound source is a small plasma generated by a high energy, laser beam focused to a point. In-flow microphone measurements are acquired in the midspan plane of the airfoil over a broad range of streamwise stations, and shielding levels are calculated over different frequency ranges from the measurements acquired with and without the airfoil installed. Shielding levels are shown to increase as the source is positioned closer to the mid-chord of the airfoil, and to significantly decrease with increasing flow Mach number, except when the source is positioned near the leading edge of the airfoil. Both with and without flow, changes in angle of attack are associated with a corresponding shift of the shadow region. Finally, the effects of multipath signals, observer distance and signal scatter on the measured shielding levels are discussed.


    Zugriff

    Zugriff über TIB

    Verfügbarkeit in meiner Bibliothek prüfen


    Exportieren, teilen und zitieren



    Titel :

    Experimental Study of Noise Shielding by a NACA 0012 Airfoil


    Beteiligte:

    Kongress:

    AIAA Aviation Forum 2018 ; 2018 ; Atlanta, GA, United States


    Erscheinungsdatum :

    2018-06-25


    Medientyp :

    Aufsatz (Konferenz)


    Format :

    Keine Angabe


    Sprache :

    Englisch


    Schlagwörter :


    Experimental Study of Noise Shielding by a NACA 0012 Airfoil

    Hutcheson, Florence V. / Bahr, Christopher J. / Thomas, Russell H. et al. | AIAA | 2018


    Experimental Study of Noise Shielding by a NACA 0012 Airfoil (AIAA 2018-2821)

    Hutcheson, Florence V. / Bahr, Christopher J. / Thomas, Russell H. et al. | British Library Conference Proceedings | 2018



    Numerical Simulation of a Pitching NACA 0012 Airfoil

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