3D-coherent acoustic intensity measurements for source identification in aircraft cabins

This work describes the results of an experimental campaign carried out to identify the correlation between the vibration of different parts of an aircraft cabin and the sound field parameters (pressure, velocity and intensity) measured at the vicinity. The reverberant cabin of the aircraft was considered as a multiple input, multiple output linear system. The inputs were the vibrations measured on different fuselage positions, while the outputs were the sound pressure, velocity and intensity close to the surface. The coherence between the vibration and the sound intensity vector was used to identify the amount of acoustic energy linearly dependent with the vibration. Experiments were performed inside the mock-up of an ATR 42 at Alenia premises, within the FP-6 framework CREDO project (Cabin noise Reduction by Experimental and numerical Design Optimization). Results showed that the 3D coherent intensity, combined with the vibration data, provides indications on the noise sources location also in reverberant conditions.