M.A. Simpson, G.P. Mathur

This paper describes measurements conducted on a DC-9 aircraft test section to define the shell and cavity modes of the fuselage, understand its structural-acoustic coupling characteristics, and measure its response to different types of acoustic and vibration excitations. Interior and exterior loudspeakers and shakers were used to excite the fuselage over the frequency range from 100 to 500 Hz, and the response to these acoustic and vibration inputs was measured with arrays of microphones and accelerometers. The data were processed to generate spatial plots and wavenumber maps of the shell acceleration and ea.bin acoustic pressure field. Analysis and interpretation of the spatial plots and wavenumber maps showed that the only structural-acoustic coupling occurred at 105 Hz between the N=2 circumferential structural mode and the (n=2, p=O) circumferential cavity mode. The fuselage response to vibration excitation was found to be dominated by low order modes which are independent of frequency, while the fuselage response to acoustic excitation was found to be dominated by modes whose order increases with frequency. This study demonstrated the usefulness of wavenumber analysis in understanding the structural-acoustic behavior of the fuselage.

DGLR/AIAA 14th Aeroacoustics Conference, 1992

Conference Paper

englisch

21,0 x 29,7 cm, 6 Seiten

DGLR-Bericht, 1992, 1992-03, DGLR/AIAA 14th Aeroacoustics Conference - Proceedings; S.958-963; 1992; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

aeroacoustics

Bibliothek

1992