The out-of-flow background noise spectrum in the test section of the full-scale low-noise automobile wind tunnel facility of BMW Technik GmbH in Munich showed a pronounced hump around 2 kHz Although this excess noise component was audible, it did not interfere with the automobile flow noise studies conducted in the tunnel An experimental study was performed to identify the source mechanism. It was found that the excess noise is generated by small cavities in the face side of the impeller blade tips When the cavities were closed the excess noise component completely dissappered The peak spectral level of the fan noise was reduced by as much as 30 dB The overall out-of-flow level reduction in the test section was 3 dB(A).


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Elimination of a High-Frequency Narrow-Band Noise Component in a Low-Noise Automobile Wind Tunnel


    Additional title:

    Sae Technical Papers


    Contributors:

    Conference:

    International Congress & Exposition ; 1996



    Publication date :

    1996-02-01




    Type of media :

    Conference paper


    Type of material :

    Print


    Language :

    English




    Elimination of a high-frequency narrow-band noise component in a low-noise automobile wind tunnel

    Heesen,W.von / Lindener,N. / Neise,W. et al. | Automotive engineering | 1996



    Multi-frequency alarm for emitting narrow band noise

    JUEL GRANT | European Patent Office | 2016

    Free access

    MULTI-FREQUENCY ALARM FOR EMITTING NARROW BAND NOISE

    JUEL GRANT | European Patent Office | 2015

    Free access

    Automobile Wind Noise Speed Scaling Characteristics

    Hou, Hangsheng | SAE Technical Papers | 2015