Internal fuselage noise: comparison of computations and tests on a Falcon airframe

Abstract

An unequipped Falcon 2000 airframe, a complex heterogeneous structure reduced to the fuselage alone, was subjected to vibro-acoustic characterization within the framework of a cooperative effort by Aerospatiale, Dassault-Aviation, and Onera. Onera's Structural Dynamics and Coupled Systems Department measured the structure's vibro-acoustic responses for four mechanical excitation configurations, and analysed three structural configurations: fuselage alone without floor, with floor, and with floor and internal wall. The resulting database of vibratory and acoustic level measurements is used for validating numerical models in the low- and medium-frequency range, as well as statistical energy analysis (SEA) models in the medium- and high-frequency range. The database was analysed by Dassault-Aviation and Onera. We present here the computation/test comparisons and the limitations of the methods in use. All of the data and comparisons validate the predictive vibro-acoustic response models and methods for a Falcon fuselage subjected to a mechanical excitation.