LAUSR

Abstract Numerical fluid analyses were performed to investigate the influence of the fiber cross-sectional shapes over the sound absorption efficiency of fibrous porous materials. The acoustic properties of the porous materials were simulated with the Johnson–Champoux–Allard (JCA) model, and the parameters were applied in a two-dimensional steady flow. Four types of fiber cross-sectional shapes were considered: circle, ellipse, three arrows, and six arrows. Each cross-sectional type had the same area as the circle for a given radius. First, the parameters for the porosity were predicted with formulas that were previously developed by the author, and compared to the values calculated in a numerical fluid analysis. Next, the sound absorption characteristics of the porous materials with four types of fiber cross-sectional shapes were evaluated with the JCA model. The results demonstrated that the formulas were applicable for various fiber cross-sections, and that the sound absorption coefficient of the fibrous porous materials changed with the fiber cross-sectional shapes. This indicates that the sound absorption efficiency of fibrous porous materials can be improved by simply changing the fiber cross-sectional shape without changing the fiber radius.