Methods used to determine a procedure for correcting static engine data for the effects of forward motion are described. Data were analyzed from airplane flyover and static-engine tests with a JT8D-109 low-bypass-ratio turbofan engine installed on a DC-9-30, with a CF6-6D high-bypass-ratio turbofan engine installed on a DC-10-10, and with a JT9D-59A high-bypass-ratio turbofan engine installed on a DC-10-40. The observed differences between the static and the flyover data bases are discussed in terms of noise generation, convective amplification, atmospheric propagation, and engine installation. The results indicate that each noise source must be adjusted separately for forward-motion and installation effects and then projected to flight conditions as a function of source-path angle, directivity angle, and acoustic range relative to the microphones on the ground.


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    Title :

    Effect of Forward Motion on Engine Noise


    Contributors:

    Publication date :

    1977


    Size :

    198 pages


    Type of media :

    Report


    Type of material :

    No indication


    Language :

    English




    Forward motion and installation effects on engine noise

    MERRIMAN, J. / GOOD, R. / LOW, J. et al. | AIAA | 1976



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