论文和技术资料

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.