Sound absorption coefficients of porous sound absorbing materials composed of two types of fibers with different diameters

Abstract

In recent years, with the spread of hybrid and electric vehicles, the number of vehicles with low engine noise has been on the rise. as the engine noise decreases, low frequency noises such as road noise and wind noise, which were not noticeable in the past, have become more prominent. in this study, we will focus on fiber based sound absorbers consisting of several diameters to predict the sound absorption characteristics. in this study, we use thinsulate as a fiber based sound absorbing material, and create a model based on the data obtained from the observation of microstructure. from this model, the sound absorption coefficient and flow resistance are calculated using the homogenization method, and the validity of the evaluation method is examined by comparing the results with actual measurements.