Determination of effective medium parameters of an in-line cavity based acoustic metamaterials with visco-thermal losses

SEÇGİN A., Baygun T.

MATERIALS RESEARCH EXPRESS, cilt.6, sa.6, 2019 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 6 Sayı: 6
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1088/2053-1591/ab0b26
  • Dergi Adı: MATERIALS RESEARCH EXPRESS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Anahtar Kelimeler: visco-thermal effects, acoustic metamaterials, effective parameters, homogenization, transfer matrix method, SOUND-WAVES, PROPAGATION
  • Dokuz Eylül Üniversitesi Adresli: Evet

Özet

The study concerns with defining effective medium parameters-such as refraction index, impedance, mass density and compressibility-of acoustic metamaterials via an inverse method with and without taking of visco-thermal effects into account. This is realized by transfer matrix method using effective medium theory through the homogenization of an acoustic metamaterial by means of a passive material. Visco-thermal effects are approximately defined in the transfer matrix equations by using Zwicker-Kosten model. The model is verified by finite element method in cases with and without visco-thermal effects. In the study, as an example, an in-line spherical cavity based acoustic metamaterial with and without visco-thermal losses is considered. The effect of visco-thermal losses on effective parameters and also on acoustic parameters such as transmission and absorption coefficients is clearly shown for the considered acoustic metamaterial.