Investigation on the broadband noise absorption performance of multiple cavity resonance liner

In the paper, multi-modal sound propagation through a duct with multiple cavity resonance acoustic liner has been theoretically investigated. The fundamental idea of the liner is dividing the back-cavity of perforated liner into several sub-cavities with different axial dimensions. Inside these sub-cavities, cut-on acoustic modes might be coupled mutually and thus multiple resonances would appear. The performance of the liner was assessed by utilizing an analytical acoustic model, which is built by adopting Transfer Element Method (TEM) that can efficiently avoid the complicated procedure of solving eigenvalues and include all propagating sound modes. According to the present results, the developed perforated liner displays comparatively good performance of absorbing multi-modal broadband noise.