Study on sound absorption properties of micro perforated plates with acoustic black hole back cavities.

In this paper, the finite element method is used to investigate the sound absorption performance of the micro perforated plates (MPPs) with acoustic black hole (ABH) back cavities. First, the finite element models of MPPs with sealed back cavities and ABH back cavities are developed. The simulation results show that the absorption bandwidth of ABH back cavities increases by 63.8% compared to the sealed back cavity of the same size, but the frequency of the highest absorption coefficient is increased. Second, the mechanism for expanding the band width is illustrated by the pressure distribution inside two cavities. Finally, the effect of different cavity numbers of stages and lengths on the sound absorption performance is analyzed. This study broadens the application scenario of MPPs by incorporating ABH back cavities and can provide a reference value for acoustic modulation. [ABSTRACT FROM AUTHOR]