Flight tests to define the far-field tone source at cruise conditions have been completed on the full-scale SR-7L advanced turboprop, which was installed on the left wing of a Gulfstream II aircraft. These measurements defined source levels for input into long-distance propagation models to predict en route noise. Infight data were taken for seven test cases. The sideline directivities measured showed expected maximum levels near 105 deg from the propeller upstream axis. However, azimuthal directivities based on the maximum observed sideline tone levels showed highest levels below the aircraft. The tone level reduction associated with reductions in propeller tip speed is shown to be more significant in the horizontal plane than below the aircraft.


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    Title :

    In-flight source noise of an advanced full-scale single-rotation propeller


    Contributors:

    Publication date :

    1991-01-01


    Type of media :

    Conference paper


    Type of material :

    No indication


    Language :

    English


    Keywords :




    Inflight source noise of an advanced full-scale single-rotation propeller

    Woodward, Richard P. / Loeffler, Irvin J. | NTRS | 1991


    In-flight source noise of an advanced large-scale single-rotation propeller

    Woodward, Richard P. / Loeffler, Irvin J. | AIAA | 1993