P. Göransson

In this paper the fundamental weaknesses of a modal base built from rigid wall acoustic modes and the reasons for the often large errors made when using these bases is discussed. It is shown that these modes, which are used in free interface modal synthesis, may be sufficient to describe the coupling between a fluid and a structure provided that the response in the fluid is of a global, modal character. If the response, however is dominated by localised radiation type of behaviour then a large number of modes is needed to achieve convergence to the correct solution. It has also been shown that in the weak sense, the convergence of the coupled solution is determined by the pressure and not necessarily by the normal derivative of the pressure. If, however, a modal base may be devised which contains modes having a nozero derivative at the boundary then an accurate solution may be achieved with only a few modes in the base as demonstrated in lhe paper.

DGLR/AIAA 14th Aeroacoustics Conference, 1992

Conference Paper

englisch

21,0 x 29,7 cm, 8 Seiten

DGLR-Bericht, 1992, 1992-03, DGLR/AIAA 14th Aeroacoustics Conference - Proceedings; S.679-686; 1992; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

NA

aeroacoustics

Bibliothek

1992