محمدرضا صفاری
Mehdi K. Dolatabadi - Department of Textile Engineering, Science and Research Branch, Islamic Azad University,Tehran, Iran
Abosaeed Rashidi - Department of Textile Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
Mohammad Esmail Yazdanshenas - Department of Textile Engineering, Yazd Branch, Islamic Azad University, Yazd, Iran

Textile structures are widely used in the sound absorber industry due to their cheap production cost and lightness. In this way a lot of research has been done to investigate the effect of structural parameters for different fabrics on sound absorption coefficient. One of the most important of these parameters is the percentage of porosity. The main aim in the paper is to examine the degree of conformity of a mathematical model and a computer simulation with the experimental results. In this study three samples of plain knitted fabric with different densities were produced and tested in terms of the sound absorption coefficient in single-layer and multi-layer modes with an impedance tube device. Investigate on the results obtained from analysis of variance method was shown that with increase of thickness and weight per square meter, the sound absorption coefficient also increases. On the other hand, an inverse relationship between sound absorption coefficient and porosity percentage was observed. In the following, the sound absorption coefficient was calculated using Dias modeling and a computer simulation for single-layer and multi-layer modes. The obtained results showed that in the computer simulation done with the Comsol software using the Delaney-Bazley method, the results related to the sound absorption coefficient show more conformity with the experimental results. This is despite the fact that in the Dias method, a good match between the theoretical and experimental results was not observed.

polyester yarn, Sound Absorption Coefficient, Weft knitting, Porosity Percentage