Identification des fréquences caracteristiques dans la transmission acoustique d'une coque finie raidie

Abstract
Computer codes for predicting noise level inside aircrafts point out some typical frequencies in noise reduction results. These phenomena are studied in this paper with help of a comparison between numerical and experimental results about a shell representing a part of Concorde fuselage ; this one is excited by plane waves with two incidences, or by a reverberant field. Numerical results about Airbus aircrafts are also used. We show the influence of the internal volume eigen-frequencies, and of frequencies assigned to the equivalent panels between frames and stringers ; the slopes of NR versus frequency are also interpreted.