https://scholars.lib.ntu.edu.tw/handle/123456789/641938
標題: | An acoustic impedance design method for tubular structures with broadband sound insulations and efficient air ventilation | 作者: | Lin, Ding Kai Xiao, Xi Wen Yang, Chieh Cheng Ho, Sheng Yu Chou, Li Chih Chiang, Che Hsien Chen, Jung San CHIEN-HAO LIU |
關鍵字: | ABCD matrix | Acoustic impedance modeling | Antiresonant mode | Broadband sound insulations | Subwavelength thickness | Ventilated tubular structure | 公開日期: | 15-四月-2024 | 卷: | 220 | 來源出版物: | Applied Acoustics | 摘要: | In this research, we proposed an acoustic impedance-based design method to increase the soundproofing bandwidths and maintain efficient air ventilation for tubular structures consisting of hollow air-flowing channels. This research has great potential to provide design guidelines based on an acoustic impedance model and even/odd mode analysis for hollow-tube ventilated devices containing resonance and antiresonances. We introduced a thin ventilated structure with a subwavelength thickness of 0.107 λ where λ corresponds to the lowest frequency within the filtering bandwidth, a 19.4 % cross-section open for air passage, and a 10 dB fractional bandwidth of 110.2 % (i.e., 90 % sound energy is blocked), which is broader than that of a conventional Fano-like structure of 44.7 %. To experimentally verify the proposed approach, two prototypes, including lateral-coupled and longitudinal-coupled devices, were designed, fabricated with 3D printing, and experimentally characterized via a commercial-available impedance tube system. The simulations matched the measurements and demonstrated the 10 dB fractional bandwidth of 65 % and 91.5 % and ventilation efficiencies of 21.4 % and 33.4 %, respectively. The main contribution of this work is that the proposed approach can be adopted for lateral or longitudinal coupled ventilated structures with broadband sound insulations and lower the effects of resonance-induced sound transmissions. Besides, the proposed acoustic-impedance model can significantly save the required tremendous computational resources and time compared to FEM simulations. Moreover, the proposed lateral and longitudinal ventilated structures are expected to benefit broadband sound filtering and noise reduction for thin panel or tubular silencers |
URI: | https://scholars.lib.ntu.edu.tw/handle/123456789/641938 | ISSN: | 0003682X | DOI: | 10.1016/j.apacoust.2024.109983 |
顯示於: | 機械工程學系 |
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