2D-Coherent Acoustic Intensity Estimation from Operational Scanning Laser Vibrometry Measurements for Sources Identification in Reverberant Fields

This paper shows the extension of the coherent intensity technique to the correlation of hi gh spatial-density multi-point sound intensity and vibration measurements by usin g a Scanning Laser Doppler Vibrometer. The coherent intensity method can be considered an output-only method for determining the structural contribution to the acoustic emission, where the inputs are the measured vibrations and the outputs the acoustic pressures measured by the microphones. The aim of this work is to understand the applicability of the technique in operatin g conditions, as hi ghly reverberatin g environments, e.g. aircraft cabins, where the location and quantification of each source is difficult by traditional techniques. The reverberant field is clearly challenging also for the proposed technique, affecting the achievable accuracy, mainly due to the fact that coherence between radiated and reverberated fields is often unknown and may be relevant. Achievable performances of the method have been analysed by sensitivity tests on a brass plate and simulations.