In this study the noise level distribution inside a fuselage model, which is excited by a shaker, is predictd using a structural-acoustic analog in NASTRAN modal synthesis. The fuselage model is represented by a stiffened, floor equipped, composite cylinder supported by rigid endcaps. Good agreement is found between NASTRAN predicted modes of the acoustic interior space and experimental acoustic modal frequencies. Interior noise level distributions predicted by the finite element model compare reasonably well with measured cross-section and longitudinal one-third octave band sound pressure level distributions. The measured interior noise level distribution due to single point shaker excitation is comparable to the distribution obtained for the composite cylinder being excited by an acoustic braodband source. It is concluded that in the frequency range of interest less than 250 Hz the interior noise level distribution is largely governed by the acoustic modal response, for the Case of a hard-walled acoustic cavity and low modal density.
Aircraft interior noise prediction using a structural-acoustic analogy in nastran modal synthesis
Berechnung des Flugzeuginnengeraeusches mit einer strukturakustischen Analogie in der Nastran Modalsynthese
1988
8 Seiten, 7 Bilder, 1 Tabelle, 14 Quellen
Aufsatz (Konferenz)
Englisch
Structural analysis of light aircraft using NASTRAN
AIAA | 1974
|Structural analysis of light aircraft using NASTRAN
NTRS | 1973
|Accuracy of results with NASTRAN modal synthesis
NTRS | 1978
|Jet noise prediction using the Lighthill acoustic analogy
Online Contents | 2004
|Prediction of vehicle interior noise using modal synthesis methods
Tema Archiv | 1994
|