DESIGN AND OPTIMIZATION OF BROADBAND SUBWAVELENGTH SOUND ABSORBING METAMATERIALS

Currently, the method to obtain broadband sound-absorbing structures typically involves the combination of multiple resonant units. Reducing the number of combined units is conducive to lowering manufacturing difficulties and optimizing the design. This paper proposes a novel partially coiled cavity, which is a composite of porous materials, cavities, and coiled space structures, to achieve broadband sound absorption. Due to the presence of cavities, the proposed unit exhibits a larger absolute bandwidth and relative bandwidth compared to traditional Fabry-Pérot coiled cavity and fully coiled cavity. We analyze the sound absorption performance of the partially coiled cavity through theoretical and simulation calculations. And We optimize the broadband sound-absorbing structure. Ultimately, by combining four designed units, we realize an average sound absorption coefficient greater than 0.95 in the range of 350 Hz to 1600 Hz. The sound-absorbing structure designed in this study features subwavelength height, simple configuration, and broad bandwidth, which has broad application prospects in noise control engineering.