Analysis of the vibracoustic behavior of a plate excited by synthetized aeroacoustic pressure fields

Denis Ricot , Abbas Hekmati , Philippe Druault (1)

1 DALEMBERT - Institut Jean Le Rond d'Alembert

Due to acoustics, comfort has become one of the principal concerns for car manufacturers, it is important to improve: (1) the knowledge of the car panel vibrations which are due to two different components: acoustic excitation and turbulent wall pressure one, and (2)the associated radiation simulation in the car interior. In this paper, first, we propose to synthetize such aeroacoustic wall pressure field based on Cholesky decomposition. Using analytical expressions of the Cross Power Spectral Density of an acoustic diffuse field and of a turbulent flow (Corcos model), spatial distributions of turbulent and acoustic excitations are determined in term of amplitude and phase in the frequency domain. Then, as a second step, the vibroacoustic behavior of a simply-supported plate excited by these synthetized fields is computed thanks to FEM calculations (ACTRAN software). The radiated field is then successively estimated for the acoustic excitation, the turbulent one and for both aeroacoustic excitations. The effect of flow inhomogeneity on the radiation field has been also regarded. Finally, a statistical analysis between radiated field and excitation fields is performed thanks to the coherence function analysis. It is then confirmed that such analysis presents some limits especially when dealing with uncorrelated sources of noise.

Mots clés: aeroacoustics; wall pressure field; plate vibration; excitation analysis

Domaines: Acoustique [physics.class-ph]

Denis Ricot, Abbas Hekmati, Philippe Druault. Analysis of the vibracoustic behavior of a plate excited by synthetized aeroacoustic pressure fields. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00811222⟩