A novel sound absorber design of nanofibrous composite porous material

Abstract

This study mainly focuses on the structural design, acoustic performance prediction, and experimental validation of a novel composite sound absorber that is similar to the feather surface structure of barn owls. The composite sound absorber is composed of an ultra-light nanofibrous membrane backed with a substrate porous materials layer (NMSPM). A theoretical NMSPM model is proposed for predicting the sound absorption coefficient (SAC) of NMSPM. The experimental results demonstrate that the nanofibrous membrane can effectively improve the acoustic performance of substrate porous materials (SPM) based on specific material parameters conditions, which also compare well with the numerical results of the theoretical NMSPM model. The applicability of the theoretical NMSPM model for different sorts of SPMs is explained based on both the experimental and numerical results. A suitable thickness range of nanofibrous membrane for effectively improving the SAC of SPM is given through a series of numerical analyses. This study may provide new thinking for a novel composite sound absorber design without weight sacrifices.

Keywords

• Nanofibrous membrane
• Sound absorption coefficient
• Biot’s theory
• Porous material