Noise control for home appliance using two-dimensional acoustic metamaterial panel composed of periodically arranged honeycomb shaped unit cells

Abstract

In this paper, a two-dimensional acoustic metamaterial panel composed of honeycombshaped unit cells in periodic arrangement was presented. The unit cell was configured with the Helmholtz resonator and an exhaust hole. The unit cell allows passage of heat and wind with minimal resistivity. Theoretical model for metamaterial panel was suggested for analyzing the noise reduction mechanism and the transmission was calculated for random incident wave. For noise control of refrigerator, the bandgap frequency was set to 600Hz considering refrigerator noise characteristics. Designed acoustic metamaterial was adopted in the machine room of a refrigerator. As a result, 0.8 dB of the overall level of the sound power level and 1.8 dB of the 600 Hz band noise were reduced. Sound power transmitted through the back structural panel was reduced significantly due to metamaterial panel without affecting radiation to the other paths.