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 where 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

中文翻译：

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宽带隔声高效通风管状结构声阻抗设计方法

在这项研究中，我们提出了一种基于声阻抗的设计方法，以增加由空心气流通道组成的管状结构的隔音带宽并保持有效的空气通风。这项研究具有巨大的潜力，可以为包含谐振和反谐振的空心管通风装置提供基于声阻抗模型和偶/奇模式分析的设计指南。我们引入了亚波长厚度为 0.107 的薄型通风结构，对应于过滤带宽内的最低频率、19.4% 的横截面开放用于空气通道，以及 110.2% 的 10 dB 分数带宽（即 90% 声能）被阻断），比传统的类 Fano 结构的 44.7% 更宽。为了通过实验验证所提出的方法，设计了两个原型，包括横向耦合和纵向耦合器件，通过 3D 打印制造，并通过商用阻抗管系统进行实验表征。模拟与测量结果相匹配，并证明 10 dB 分数带宽分别为 65% 和 91.5%，通风效率分别为 21.4% 和 33.4%。这项工作的主要贡献是，所提出的方法可以用于具有宽带隔音的横向或纵向耦合通风结构，并降低共振引起的声音传输的影响。此外，与有限元模拟相比，所提出的声阻抗模型可以显着节省所需的大量计算资源和时间。此外，所提出的横向和纵向通风结构预计将有利于薄板或管式消音器的宽带声音过滤和降噪