A single-bladed AH-1 helicopter rotor blade has been tested to high tip Mach numbers ( M T = 0.8 ) in a hovering acoustically treated test chamber in the presence of vertical gust fields. The vertical gust velocity field has been tailored to closely replicate the impulsive vortex-induced velocity field, thus simulating a single blade–vortex interaction event. The controlled vertical gust disturbance is tailored to simulate the acoustic phasing of parallel, oblique, and a specially designed curved blade–vortex interaction that causes aerodynamic singularities to occur during the interaction process. Far-field acoustic signatures have been measured using a microphone grid in the near in-plane as well as out-of-plane observer regions. Comparisons with theoretical acoustic calculations using computational-fluid-dynamics inputs have yielded good results for the out-of-plane measurement locations, generally validating the use of computational fluid dynamics coupled with linear acoustic theory. At near-in-plane observer regions, comparison with linear acoustic theory calculations showed major discrepancies, indicating that a more in-depth analysis of both the theoretical and experimental approaches is required.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Measurements and Computations of Experimentally Simulated Blade-Vortex Interaction Noise


    Contributors:

    Published in:

    AIAA Journal ; 52 , 10 ; 2241-2250


    Publication date :

    2014-10-01




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English





    Measurements and CFD-Based Acoustic Computations of Experimentally Simulated Blade-Vortex Interaction (BVI) Noise

    Koushik, S. / Gopalan, G. / Schmitz, F. et al. | British Library Conference Proceedings | 2009


    Rotor blade-vortex interaction noise

    Yu, Yung H. | Online Contents | 2000


    Elastic blade-vortex interaction noise

    Howe, M.S. | Online Contents | 1994


    Directionality of Blade Vortex Interaction Noise

    Open, C. M. / Patrick, M. J. / Associazione Italiana di Aeronautica ed Astronautica et al. | British Library Conference Proceedings | 1993