Development of an empirical model for the prediction of the airflow resistivity of thin and low-density fibrous materials

This study develops an empirical model to predict the airflow resistivity of thin and low-density sound-absorbing materials. Airflow resistivity is a key input parameter for Finite Element Method (FEM) simulations of sound pressure levels (SPLs) in vehicle cabins. However, existing models for determining the airflow resistivity of thin and low-density fibrous materials are inaccurate. Therefore, this study proposes a simple and reliable model based on multiple linear regression analysis of polypropylene fibrous nonwoven samples. The samples were tested using equipment designed according to ISO standards 9053-1. The model selection was performed using stepwise techniques to identify the most relevant predictors. The final model, along with its coefficients and goodness of fit statistics, is presented and discussed. The results of this study offer a practical tool for design engineers to estimate the airflow resistivity of thin and low-density materials, which can improve the accuracy of FEM simulations of SPLs in vehicle cabins.