LAUSR

Thermoviscous dissipation plays an important role in sound propagation through acoustic metastructures for a variety of applications. The thermoviscous effects rely on the resonances in the structures of subwavelength features. Our analyses and numerical simulations reveal that thermoviscous dissipation can significantly reduce the transmission of sound waves through acoustic metastructures of hybrid resonances in certain scenarios even when the thickness of the viscous boundary layer is much smaller than the width of the slit in the structure [Jiang et al., J. Acous. Soc. Am. (2017)]. To further explore how the resonances affect the significance of the losses, we analyze and simulate sound propagation in acoustic metamaterials of various configurations, including a slit connected to one or multiple resonators at the side of the slit or at the end of the slit. We take into account both wall friction and thermoviscous diffusivity in both the slits and the resonators. The results are compared with that with...