Acoustic band gaps for a two-dimensional periodic array of solid cylinders in viscousliquid

Abstract

We investigated the absolute acoustic band gaps for two-dimensional periodic arrays ofsilica cylinders in viscous liquid. Acoustic band structures, which have complexeigenfrequencies for these systems, are calculated with the plane wave expansion method.They show that when the viscous penetration depth is comparable to the structural lengthscale, the structures possess large absolute acoustic band gaps compared with thosewithout viscosity. We also found that the magnitude of the viscosity plays an importantrole in these band gaps.