Numerical Modelling of the Acoustic Properties of Polyester Non-woven

This paper investigates the acoustical properties of polyester non-woven by using practical and numerical methods. Several types of non-woven samples made from staple, hollow and bi-component polyester fibres were chosen to carry out this study. The AFD300 Acoustic Flow device was used to measure airflow resistivity. The 45 mm Materiacustica two-microphone impedance tube was used to measure the surface impedance and sound absorption coefficient. Widely used impedance models, such as the Delany-Bazley, Miki, Garai-Pompoli and Komatsu models, were applied to predict acoustical properties. A comparison between measured and predicted values has been performed to derive the most accurate model. The Johnson-Champoux-Allard-Lafarge (JCAL) model was applied to obtain some non-acoustical properties based on the inverse method. It is found that the Delany-Bazley and Miki models can accurately predict the surface impedance of polyester non-woven. The results indicate that the Miki model is the most acceptable method for predicting the sound absorption coefficient, with an 8.39% mean error for all of the samples. The values are 8.92%, 12.58% and 69.67% for the Delany-Bazley, Garai-Pompoli and Komatsu models, respectively. Several difficult-to-obtain parameters have been investigated.