Infrasound transmission of non porous windscreens

Nicolas Dauchez (1, 2) , Maxime Hayot , Stéphane Denis

1 LAUM - Laboratoire d'Acoustique de l'Université du Mans
2 LISMMA - Laboratoire d'Ingénierie des Systèmes Mécaniques et des MAtériaux

Outdoor measurement of infrasound requires the use of windscreens to reduce the noise due to aerodynamic perturbations. Usual methods are based on a spatial averaging of the pressure using a multiple-inlet pipe network or a wind barrier. The size of such systems is no smaller than several meters, therefore not compatible with portable infrasound measuring chains. To overcome these limitations, a study on nonporous polymer foam windscreens smaller than 1 meter has been carried out [J. Acoust. Soc. Am. 118(3), 1335-1340 (2005); J. Acoust. Soc. Am. 127(6), 3327-3334 (2010)]. However the link between prediction and measurement of infrasound transmission has not been clearly established. In this paper, an analytical vibroacoustic model using the long wavelength hypothesis is proposed. The geometry considered is an elastic nonporous plate coupled with a cavity connected to the pressure sensor. A good agreement with finite element modeling and experimental data is found. Finally, rules to design an optimized system, related to geometry and material properties, are given.

Mots clés: infrasound; acoustic transmission; non porous windscreen; structural acoustics

Domaines: Acoustique [physics.class-ph]

Nicolas Dauchez, Maxime Hayot, Stéphane Denis. Infrasound transmission of non porous windscreens. Acoustics 2012, Apr 2012, Nantes, France. ⟨hal-00810819⟩