Acoustic modeling of three-dimensional-printed fibrous sound absorbersa).

In this study, an analytical model was developed to predict the sound absorption performance of fibrous absorbers fabricated using an extrusion-based three-dimensional (3D) printing method. The proposed model employs geometric design parameters, including the average fiber diameter and the horizontal and vertical fiber separations, to calculate the porosity, static airflow resistivity, tortuosity, and viscous and thermal characteristic lengths. These transport parameters are then used within the Johnson-Champoux-Allard semiempirical formulation to predict the normal incidence sound absorption coefficient.