Aerogels are defined as mesoporous materials obtained by replacing the liquid phase within a gel by a gaseous phase, typically air. This underlying mesoporous structure provides aerogels unique macrostructural properties such as ultralow density, high transparency, and low thermal conductivity. Given their ultralow density, aerogels are also an attractive, lightweight solution for noise control applications. Recent studies have shown that the acoustical properties of granular aerogels are very different from those observed for other granular media. In this presentation, we present results from our recent investigation of the acoustical behavior of Enova IC3100 aerogel granules. Manufactured and commercially sold by Cabot Corporation, IC3100 aerogels are characterized by their comparatively smaller granule dimensions. Our previous experimental measurements show that the acoustical performance of the IC 3100 aerogel granules differs from conventionally used sound absorption materials; multiple, lightly damped depth resonances with large peak values of absorption coefficients are observed low frequencies. Here, we present results from our attempt to model the acoustical behavior of IC3100 aerogels. The acoustical-related bulk properties required for the Johnson-Champoux-Allard (JCA) model are calculated using an inverse characterization approach. These properties are then used to model the acoustical behavior of the granular aerogel layer using the Biot theory for porous media.
Aerogels, Poro-elastic, Modeling, Sound absorption, Biot model
Acoustics and Noise Control
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