Estimation Method for Non-acoustic Parameters of the Johnson-Champoux-Allard Model using Genetic Algorithm

In this paper, an advanced method is proposed for estimating the non-acoustic parameters of porous materials. The parameters targeted for estimation include flow resistivity, porosity, tortuosity, and the thermal and viscous characteristic lengths within the Johnson-Champoux-Allard model. A genetic algorithm was employed as an optimal design technique to perform the estimation. To compute the objective function, the sound absorption coefficient and surface impedance were calculated within the 1/3 octave band, with Delany-Bazley’s law providing supplementary support. The results demonstrate that estimation accuracy improves for materials exhibiting relatively higher porosity and lower tortuosity.