Bandgap characteristics of a duct embedded with multiple membrane-cavity resonators in the presence of mean flow

Bandgap characteristics of periodic structures can be investigated by the effective material properties via reflection and transmission coefficients. In this paper, for the first time, corresponding effective properties such as mass density, relative impendence and refractive index are presented for a duct embedded with membrane-cavity resonators in its sidewalls. Around the membrane or cavity resonant frequencies, the effective density varies...