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Description
Broadband noise attenuation in ventilated duct systems remains challenging in the low-to-mid frequency range. This study proposes a ventilated acoustic black hole-micro-perforated panel (ABH-MPP) structure that combines axial geometric variation with sidewall micro-perforations to enhance thermoviscous dissipation. A one-dimensional transfer matrix model is developed and validated against finite element simulations and available data from the literature. Results show broadband sound power dissipation and transmission loss without relying on conventional resonant mechanisms. Introducing internal partitions further enhances dissipation by extending thermoviscous losses from the sidewalls to the partition surfaces, leading to stronger distributed attenuation along the propagation path. Time-domain analysis indicates that the MPP does not weaken the intrinsic slow-wave effect of the ABH; instead, it increases the residence time of acoustic energy and promotes sustained dissipation. Parametric studies identify the influence of key geometric parameters and support a mechanism-based design approach. The ventilation capability of the proposed structure is also evaluated under a typical flow condition, demonstrating that a continuous airflow passage can be maintained.