Application of equivalent diameter in sound absorption performance prediction of non-circular sectional polyester fibers

Abstract Polyester fiber as good sound absorber is used widely in various scenario. But there are few researches on model prediction of sound absorption property for the polyester fiber with non-circular cross-section. Polyester samples made from circle, triangle, flat, and cross cross-sectional fiber were prepared under different bulk densities separately in this study. Their airflow resistance values and sound absorption coefficients with 50 mm air cavity were measured. The equivalent diameters were acquired by analytical inverse method. Johnson-Champoux-Allard (JCA) model was adopted with the equivalent diameter to calculate the sound absorption coefficient of non-circular polyester fiber material. The results showed that sound absorption performance of non-circular fiber was higher than that of circular one at the similar bulk density before airflow resistance critical value. The equivalent diameters of non-circular fibers were less than circular one. Sound absorption coefficients obtained by the equivalent diameters (about 10 μm) were in good agreement with the experimental values. But to guarantee calculation accuracy, the equivalent method should be applied in the case of airflow resistance less than 100,000 Pa·s/m2.