Combining granular aerogels with additively manufactured porous structures for broadband sound absorption

Our recent investigation [1] showed that the absorption behavior of granular aerogel agglomerates with average particle diameters less than 50μm is dominated by periodically spaced, high absorption peaks and troughs. While the absorption peaks, especially at lower frequencies, are desirable from an engineering application perspective, overcoming the loss in high frequency performance remains a challenge. Furthermore, the practical application of granular aerogels is limited by the difficulty in handling them. In this work, we propose a new design for a broadband noise absorber achieved by layering the aerogel granules within a 3D printed porous network. The design provides a robust method of incorporating aerogels within noise reduction packages and can be tailored by altering the rigid porous network and the layering arrangement. In this presentation, we present our preliminary findings regarding the fabrication and testing of such hybrid sound absorbers. [1] Dasyam A, Xue Y, Bolton JS, Sharma B. Effect of particle size on sound absorption behavior of granular aerogel agglomerates. Journal of Non-Crystalline Solids. 2022 Dec 15;598:121942.