Investigation of the Schoch effect based on acoustic collective surface oscillation

Abstract

In this research, the Schoch effect of periodic addition of a rectangular acoustic grating system on the structures of Helmholtz resonators is investigated. The results reveal that positive and negative Schoch shifts can be obtained in the investigation system. The phase of the effective refractive index of the resonator changes by π rad at the resonance frequency when positive Schoch shifts occur. However, it is the phase of the resonator's reflectance coefficient and not the effective refractive index that varies by 2π rad at the resonant frequency when a negative Schoch shift occurs. The findings also show that the system's resonance frequencies can be adjusted by changing the parameters of the structure. When the effective refractive index of the structure is close to or equal to zero, the corresponding frequency is the resonance frequency. At this frequency, the Schoch effect and a significant acoustic collective surface oscillation are observed.