Microstructure modeling of microfiber sound absorbers and investigation of improvement of sound absorption coefficient

Abstract

In the automotive industry, various studies have been conducted to reduce cabin noise. Currently, it is common to use sound-absorbing materials in door panels and front panels to reduce low-frequency noise such as road noise and wind noise. Porous materials such as glass wool and urethane foam are used as sound-absorbing materials, but they currently have problems such as low sound absorption performance at low frequencies. Therefore, this study focused on fiber-based sound-absorbing materials consisting of multiple diameters. A microstructural model was created based on data obtained from microstructural observations of this fiber material. Using this model, flow resistance and sound absorption coefficient were calculated by the homogenization method. The results of the calculations using the model with bundled fibers showed that the effect of changes in the flow path area was significant.