AERNNOVAs activities performed in the work package related with cabin noise reduction inside FRIENDCOPTER project were focused on evaluation of damping performance of different APSCLDT (Active-Passive Segmented Constrained Layer Damping Treated) panels. Evaluation of noise and vibration reduction for different segmentations of APSCLDT panels were analyzed with commercial and own codes, correlated and tested in laboratory on special acoustic cavity. Different treated panels were tested in passive and active mode in order to compare noise reductions. Panels and acoustic cavity were acoustically excited by a speaker with white noise (band width 3.5 kHz) meanwhile the noise generated inside the cavity was measured with pressure microphone. Although no significant noise reductions were obtained, quite surprising results emerged from acoustic cavity tests. Obtained results clearly show that contribution of all structural panel resonances to overall noise in an enclosure have minor effect on overall interior cavity noise in comparison with acoustic resonance amplifications. Acoustic resonance amplifications are the main and most important noise carriers and contributors in enclosures. Panels have much more influence on excitation of acoustic resonances than on noise radiation. In other words helicopter panels are not so much noise radiators as they are exciters of acoustic resonances inside an enclosure like helicopter cabin.


    Access

    Access via TIB

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Acoustic cavity with active- passive segmented constrained layer damping treated panels


    Contributors:


    Publication date :

    2008


    Size :

    14 Seiten, 14 Bilder, 3 Tabellen, 3 Quellen



    Type of media :

    Conference paper


    Type of material :

    Storage medium


    Language :

    English




    Active/Passive Control of Sound Radiation from Panels Using Constrained Layer Damping

    Gibbs, G. / Cabell, R. / American Institute of Aeronautics and Astronautics | British Library Conference Proceedings | 2003



    Modeling Segmented Active Constrained Layer Damping Using Hybrid Displacement Field

    Aditi Chattopadhyay / Haozhong Gu / Rajan Beri et al. | AIAA | 2001


    Modeling segmented active constrained layer damping using hybrid displacement field

    Gu, Haozhong / Chattopadhyay, Aditi / Nam, Changho | AIAA | 1999


    Modeling Segmented Active Constrained Layer Damping Using Hybrid Displacement Field

    Chattopadhyay, A. / Gu, H. / Nam, C. | British Library Conference Proceedings | 1999