Acoustic Metamaterial for Low‐Frequency Sound Absorption in Urban Substations

ABSTRACT

To address the challenges of noise control in urban substations, a detailed noise characteristic analysis was conducted, identifying 100, 200 and 300 Hz as the primary low‐frequency noise components. To effectively absorb these frequencies, a neck‐embedded honeycomb‐shaped Helmholtz resonator was proposed, with its structural parameters optimised via genetic algorithms for selective sound absorption. An ultrastructured acoustic plate was then designed using array coupling between cavities and numerical analysis methods. Simulation results demonstrated that the proposed model achieved absorption coefficients exceeding 0.9 at the target frequencies. Experimental validation, conducted using impedance tube testing on a 3D‐printed version of the acoustic plate, showed strong agreement with the simulation results, confirming the potential and practicality of the proposed ultrastructured material for low‐frequency noise reduction in urban substations. Finally the application effect of acoustic metamaterial was testified using acoustic field simulation in a 110 kV substation.