Abstract: Disclosed herein is an acoustic metamaterial structure which can effectively reduce noise in a specific frequency range through formation of an acoustic bandgap, wherein the specific frequency range is determined by a periodic structure formed by an array of multiple unit cells. The acoustic metamaterial structure includes multiple first unit cells each including a first space having a first cross-sectional area and a second space disposed downstream of the first space in a flow direction of fluid to communicate with the first space, the second space having a second cross-sectional area larger than the first cross-sectional area, wherein the acoustic metamaterial structure reduces noise in a specific frequency range through formation of an acoustic bandgap, the specific frequency range being determined by a periodic structure formed by an array of the first space and the second space.

Abstract: Disclosed herein is an acoustic metamaterial structure which can effectively reduce noise in a specific frequency range through formation of an acoustic bandgap, wherein the specific frequency range is determined by a periodic structure formed by an array of multiple unit cells. The acoustic metamaterial structure includes multiple first unit cells each including a first space having a first cross-sectional area and a second space disposed downstream of the first space in a flow direction of fluid to communicate with the first space, the second space having a second cross-sectional area larger than the first cross-sectional area, wherein the acoustic metamaterial structure reduces noise in a specific frequency range through formation of an acoustic bandgap, the specific frequency range being determined by a periodic structure formed by an array of the first space and the second space.