发表机构
Beijing University of Technology; Tsinghua University; Nanjing University of Aeronautics and Astronautics（北京工业大学; 清华大学; 南京航空航天大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出利用柔性边界建立水与空气声学介质的直接映射，使充水通道模拟空气等效传播，并在深亚波长厚度下实现接近因果极限的宽带水下吸声，为跨介质声学功能移植开辟新途径。
AI 中文摘要
水与空气之间极大的阻抗失配（约3600倍）长期以来一直是分离水下声学与空气声学的基本障碍。在此，我们利用柔性边界克服了这一障碍，该边界在不同声学介质之间建立了直接的物理映射，使充水通道能够模拟空气等效的波传播。通过振动声学耦合，有效波速以近似无频散的方式被重新标定，产生具有可调衰减的慢波。利用这一概念，我们展示了在接近因果极限的深亚波长厚度下实现宽带水下吸声。我们的发现表明，声学介质可以通过边界动力学而非体相组成来重塑，为跨不同介质移植声学功能及超材料设计铺平了道路。
英文摘要
The extreme water-air impedance contrast (~3600) has long acted as a fundamental barrier separating airborne and underwater acoustics. Here, we overcome this barrier with flexible boundaries, which establish a direct physical mapping between disparate acoustic media, enabling a water-filled channel to emulate air-equivalent wave propagation. Through vibroacoustic coupling, the effective wave velocity is rescaled in an approximately nondispersive manner, producing slow waves with tunable attenuation. Leveraging this concept, we demonstrate broadband underwater sound absorption at a deep-subwavelength thickness approaching the causal limit. Our findings reveal that acoustic media can be reshaped via boundary dynamics rather than bulk composition, paving the way for transplanting acoustic functionalities and metamaterial design across distinct media.
