Recent programs in the field of jet noise, sponsored by the NASA Lewis Research Center, have indicated that the variable stream control engines (VSCE) which are being considered for advanced supersonic cruise aircraft have inherent jet noise advantages over earlier engines. This characteristic is associated with the exit velocity profile produced by such an engine. The high velocity fan stream, on the outer periphery, is acoustically dominant while the primary stream is held to a low velocity and therefore contributes little to the overall noise. Scale model tests have indicated low noise levels. Operation under static conditions, as well as in a relative velocity field (simulating take-off speeds) has indicated large reductions are available from the coannular nozzle and the VSCE. The inherently low levels of jet noise prompted changes in the cycle, which allowed an increase in the amount of augmentation incorporated in the fan stream, without exceeding the suggested noise guidelines, thereby allowing the use of a considerably smaller engine, with obvious vehicle advantages.


    Access

    Access via TIB

    Check availability in my library


    Export, share and cite



    Title :

    Coannular nozzle noise characteristics and application to advanced supersonic transport engines


    Contributors:


    Publication date :

    1976-01-01


    Type of media :

    Conference paper


    Type of material :

    No indication


    Language :

    English




    Coannular supersonic ejector nozzles

    Bishop, A. R. | NTRS | 1979




    PLIF investigation of coannular supersonic jets

    Murakami, Erina / Papamoschou, Dimitri | AIAA | 1998


    PLIF Investigation of Coannular Supersonic Jets

    Murakami, E. / Papamoschou, D. / AIAA | British Library Conference Proceedings | 1998