Homogenization of In-line Cavity Based Acoustic Metamaterials and The Determination of Transmission Losses via Transfer Matrix Method

In this study, a variety of acoustic metamaterials consisting of in-line cavity based metacells are designed, for use as insulation material with high sound transmission loss. The transmission losses of these materials were determined by the transfer matrix method (TMM) with neglecting visco-thermal losses. Effective medium parameters such as effective impedance, refractive index, density and compressibility (inverse of Bulk modulus) of the metamaterials are obtained by effective medium homogenization. The effects of number of metacells, geometric size and the periodicity of the elements on the transmission loss (TL) are examined, and the performance of the metamaterials regarding frequency domain is discussed. The accuracy of the present method is demonstrated by finite element method. In the study, the topological issues such as acoustic metamaterial design and analysis and obtaining effective parameters with effective medium homogenization using the TMM, are presented in detail