D. Otte, H. Van der Auweraer, M. Gustavsson, U. Emborg

The interior noise in propeller aircraft is currently an important issue in the aerospace industry. Effective noise control measures not only require a thorough understanding of the in-flight behaviour, but preferably need the development of a representative model of the complex vibro-acoustic system, built up by fuselage, trimpanels and cabin cavity. This conceptual paper discusses some global experimental modeling ·techniques for such complex vibro-acoustic systems, based on singular value decomposition of a measured Frequency Response Function matrix. Two related modeling concepts, Principal Field Shape Analysis and the U-vector Expansion Method (Impedance Modeling) are introduced and illustrated by test examples on a fully trimmed twin-engine aircraft. The paper also describes some flight data analysis techniques, based on coherence methods. Advanced techniques to separate the individual propeller contributions are based on cross-spectral averaging, using tacho-signals as references. Alternatively, a more global analysis method based on Principal Component Analysis is introduced and evaluated.

DGLR/AIAA 14th Aeroacoustics Conference, 1992

Conference Paper

englisch

21,0 x 29,7 cm, 7 Seiten

DGLR-Bericht, 1992, 1992-03, DGLR/AIAA 14th Aeroacoustics Conference - Proceedings; S.964-970; 1992; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

aeroacoustics, propellers

Bibliothek

1992