Effect of the perforation shape on the absorption coefficient of multi-layer absorbing system

타공형태에 따른 다중 다공판 시스템의 흡음률 변화

Various types of perforated sheets have been applied on the surface of porous absorptive materials in order to protect dust and to enhance interior design. This study examines experimentally influences on absorptive characteristics according to the shape of perforation which includes rectangular and resonator type as well as circular holes. The measured results shows that the resonance frequency can be changed by the shape of perforation as well as the eccentricity of holes.