Customized sound mitigation with micro-perforated panels

Abstract

Micro-perforated panels in combination with an air-tight back volume constitute the micro-perforated absorber (MPA), an alternative means in the category of sound absorbing (meta)materials. In contrast to the conventional porous and fibrous materials, the MPA does not mitigate sound in broad frequency range, but rather has to be customized to a specific noise frequency range. In this contribution, we demonstrate the simulation framework based a genetically fitted equivalent fluid model. Application examples show the advantages and disadvantages of using MPAs in room acoustic scenarios as well as with a background mean flow in ducts. The investigations found that the MPA's effectiveness strongly depends on the sound field characteristic. The MPP's surface roughness and back volume composition in-part significantly influence the efficiency of an adjacent turbo-machine.