Technical Papers and Presentations

Granular materials have been conventionally used for acoustic treatment due to their sound absorptive and sound insulating characteristics. An emerging field is the study of acoustical properties of multi-scale porous materials. An example of these is a double-porosity granular material in which the grains are porous themselves. In this work, a computational methodology for modelling this type of materials is presented using COMSOL. It is based on the homogenization of periodic media technique and accounts for rarefaction effects under non-isothermal sound propagation condition at the microscopic level. It is concluded that a double-porosity granular material exhibits reduced weight, remarkable low-frequency sound absorption enhancement and higher transmission loss for a given frequency range compared to its single-porosity counterpart.