Identification of noise sources in aircraft cabins proves to be difficult particularly at low frequencies. A new approach, based on the Inverse Finite Element Method, reconstructs the spatial distribution of sound pressure and particle velocity. This procedure requires measurements in the cavity first. If all sound sources are located on the boundary, the equation system resulting from a matching Finite Element model can be re-sorted in such a way that computation of the unknown boundary data is possible, even with distorted measurement data. The sound field in the cavity of an aircraft mock-up (Airbus A340) excited by both interior and exterior noise sources is mapped with a custom-built microphone array. A matching acoustic model of the mock-up is verified and compared to the mapping data. Consequently the inverse calculation is performed, using the measurement data. In upcoming research, the IFEM technique will have to be stabilized and made numerically more efficient, sensitivity studies concerning the reduction of measurement data will be performed to make the method more applicable, and the calculation will be repeated using the data measured with external loudspeaker excitation.
Inverse identification of noise sources in aircraft interiors
Inverse Identifikation von Geräuschquellen in Flugzeugkabinen
2009
9 Seiten, 7 Bilder, 8 Quellen
Aufsatz (Konferenz)
Englisch
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