Proposta Accordo Bilaterale CNR-CNRS: Innovative nonlinear audio excitation source for acoustic metrology - InAx

The Institute of Acoustics and Sensors "O. M. Corbino" - IDASC, and the Institute Jean Le Rond d'Alembert (DALEMBERT) propose to investigate the effectiveness of the parametric array in air for different applications: Non Destructive Testing (NDT) and quality enhancement of acoustical environments. The project accounts for a theoretical study and a set of acoustical measurements. Regarding the theoretical model, the goal is to complete a flexible simulation tool representing the nonlinear propagation in air. The idea is to extend the general model of nonlinear propagation based on the spatial Fourier formalism, initially developed by DALEMBERT institute for underwater purpose. It allows taking into account different antenna geometries, and both the nearfield and farfield components of the transmitted wave are derived. After its validation, the extended model will help the optimization of the parametric transducer. Concerning the experimental activity, the improved parametric array will be integrated in measuring systems to accomplish enhanced version of these apparatus, such as: a better signal to noise ratio, a higher resolution and a greater portability. These equipments will allow to realize measurements of the acoustic absorption and reflection coefficient in materials and structures such as objects of heritage interest, road pavements, and sound absorbers. Thus the project combines solid theoretical competences for modeling with an experimental practice toward civil and industrial fields. This study also answers the needs in various NDT applications.