To achieve a noticeable improvement of the acoustic comfort in aircraft cabins both, the noise sources, and the optimal positions for noise absorbers must be determined. For this reason, the paper presents innovative concepts of detecting noise sources in weakly damped aircraft interiors and experimental results on optimized active noise control at high tonal noise levels. In the first part of the paper an inverse method for noise source identification has been presented. This approach is based on a Finite Element Model of the interior sound field in the frequency domain. In order to verify the inverse sound source identification method, such models can be applied to predict the sound pressure distribution in the interior by a standard FE-simulation. Data taken from a certain subspace of the investigated interior - called measurement area - can be used afterwards as boundary conditions for the inverse calculation. The IFEM approach was successfully applied to simple two dimensional models as well as to more sophisticated models of an airplane cross section area. Applying regularization techniques it was possible to recalculate the original sound pressure distribution at the interior boundary, even if an error of 8 % has been superimposed on the data taken from the measurement area. In the second part of this paper a new method for optimizing the actuator and sensor positions for such a system has been described. The transfer functions between all possible actuator and sensor positions were measured in a mock up of the LMA. Based on this data the minimum number and optimal position of the actuators and sensors were computed. The expected noise reduction and the necessary electrical input were calculated for the configuration obtained. These data were successfully compared with measurement data for the optimal setup that was implemented into a mock-up.


    Zugriff

    Zugriff über TIB

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    Noise source identification and optimized active noise control in aircraft cabins


    Beteiligte:


    Erscheinungsdatum :

    2007


    Format / Umfang :

    10 Seiten, 6 Bilder, 1 Tabelle, 7 Quellen




    Medientyp :

    Aufsatz (Konferenz)


    Format :

    Print


    Sprache :

    Englisch




    Global Active Noise Control in Aircraft Cabins

    Grebkowski, J. / Bohme, S. / Sachau, D. et al. | British Library Conference Proceedings | 2009


    Global Active Noise Control in Aircraft Cabins

    Greßkowski, Julian / Böhme, Sten / Sachau, Delf | AIAA | 2009