The invention relates to an aircraft turbofan type engine (1) comprising an air intake duct (2) having an inner face provided with an acoustic attenuation shroud (11) located upstream from a fan (3) of this engine (1). This acoustic attenuation shroud (11) comprises a regular alternation of first portions and second portions with different first and second thicknesses along the radial direction, the number of alternations being greater than twice the number of passing azimuth acoustic vibration modes occurring in the engine (1) without the acoustic attenuation shroud (11) operating under conditions corresponding to a landing phase and a take-off phase.


    Access

    Download


    Export, share and cite



    Title :

    Reduction of turbofan noise


    Contributors:

    Publication date :

    2021-09-22


    Type of media :

    Patent


    Type of material :

    Electronic Resource


    Language :

    English


    Classification :

    IPC:    F02C Gasturbinenanlagen , GAS-TURBINE PLANTS / B64D Ausrüstung für Flugzeuge , EQUIPMENT FOR FITTING IN OR TO AIRCRAFT



    Noise Reduction of a Turbofan Bleed Valve

    Phong, Vincent / Taghavi Nezhad, Shervin / Liu, Feng et al. | AIAA | 2012


    Noise Reduction of a Turbofan Bleed Valve

    Phong, V. / Nezhad, S.T. / Liu, F. et al. | British Library Conference Proceedings | 2012


    Aircraft turbofan noise

    Groeneweg, J.F. / Rice, E.J. | Tema Archive | 1982


    Technologies for jet noise reduction in turbofan engines

    Mofid Gorji-Bandpy / Mohammadreza Azimi | DOAJ | 2012

    Free access

    Turbofan noise reduction using a near sonic inlet

    KOCH, R. / CISKOWSKI, T. / GARZON, J. | AIAA | 1974