A Study on the Sound Absorption of Multiple Layer Perforated Plate Systems Combined with Porous Absorbing Materials

다공성 흡음재가 조합된 다중 다공판 시스템의 흡음성능에 관한 연구

The sound absorption coefficients for multiple layer perforated plate systems containing several compartments with airspaces and porous absorbing materials are estimated using the transfer matrix method developed in the previous paper. The absorption coefficients from transfer matrix method agree well with the values measured by the two-microphone impedance tube method for various combinations of perforated plates, airspaces or porous materials. Based on these results, a guidance for the design of multiple layer perforated plate systems combined with airspaces and porous absorbing materials is discussed in detail.