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Padois T.,Groupe Dacoustique Of Luniversite Of Sherbrooke Gaus | Gauthier P.-A.,Groupe Dacoustique Of Luniversite Of Sherbrooke Gaus | Berry A.,Groupe Dacoustique Of Luniversite Of Sherbrooke Gaus
Journal of Sound and Vibration | Year: 2014

Microphone arrays have become a standard technique to localize and quantify source in aeroacoustics. The simplest approach is the beamforming that provides noise source maps with large main lobe and strong side lobes at low frequency. Since a decade, the focus is set on deconvolution techniques such as DAMAS or Clean-SC. While the source map is clearly improved, these methods require a large computation time. In this paper, we propose a sound source localization technique based on an inverse problem with beamforming regularization matrix called Hybrid Method. With synthetic data, we show that the side lobes are removed and the main lobe is narrower. Moreover, if the sound noise source map provided by this method is used as input in the DAMAS process, the number of DAMAS iterations is highly reduced. The Hybrid Method is applied to experimental data obtained in a closed wind-tunnel. In both cases of acoustic or aeroacoustic data, the source is correctly detected. The proposed Hybrid Method is found simple to implement and the computation time is low if the number of scan points is reasonable. © 2014 Elsevier Ltd. Source

Boulandet R.,Groupe Dacoustique Of Luniversite Of Sherbrooke Gaus | Michau M.,Groupe Dacoustique Of Luniversite Of Sherbrooke Gaus | Michau M.,CNRS Laboratory of Mechanics and Acoustics | Micheau P.,Groupe Dacoustique Of Luniversite Of Sherbrooke Gaus | Berry A.,Groupe Dacoustique Of Luniversite Of Sherbrooke Gaus
INTERNOISE 2014 - 43rd International Congress on Noise Control Engineering: Improving the World Through Noise Control | Year: 2014

This paper addresses an active structural acoustic control (ASAC) approach to reduce sound transmission through an aircraft trim panel. The focus is on the practical implementation of the virtual mechanical impedance approach through self-sensing actuation instead of using sensor-actuator pairs. The experimental setup includes two sensoriactuators designed from an electrodynamic inertial exciter and distributed over an aircraft trim panel, which is subject to a time-harmonic diffuse sound field. A methodology based on the experimental identification of key parameters of the actuator is proposed, wherein the vibration of the structure is estimated from the electrical signals picked up at the input terminals of the transducer. Measured data are compared to results obtained with conventional sensor-actuator pairs consisting of an accelerometer and an inertial exciter, particularly as regards sound power reduction. The decrease of sound power radiated is comparable in both cases and equals 3 dB when the panel is controlled at the excitation frequency of 363 Hz, as expected by optimal calculation for two control units. Source

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