Unlike acoustic models developed for specific materials, Johnson Champoux Allard model is widely used by researchers and industry people. However, this model needs five intrinsic properties, such as Porosity, Flow resistivity, Tortuosity, Viscous, and Thermal characteristic length. Among the five first two properties can be measured using experimental setup without difficulties, the rest of the three needs dedicated test setup and that too do not have any approved standards. To outwit this problem, an inverse characterization using experimental impedance tube data is a phenomenal one. In this study, three different loading percentages like 3, 5, and 10 of two different forms fibers are used as filler in polyurethane Foam (PuF) composite. Using the transfer function method sound absorption coefficient of PuF composite is calculated experimentally then validated by two techniques one is inverse characterization using the Genetic algorithm and another one is hybrid technique using two measured and three estimated properties. The predicted intrinsic properties used in JCA model show good agreement with experimental results.
Volume 11 | Issue 6
Pages: 404-417