Our work investigates a tunable multilayer composite structure for applications in the area of low-frequency absorption. This acoustic device is comprised of three layers, Helmholtz cavity layer, microperforated panel layer, and the porous material layer. For the simulation and experiment in our research, the absorber can fulfill a twofold requirement: the acoustic absorption coefficient can reach near 0.8 in very low frequency (400 Hz) and the range of frequency is very wide (400–3000 Hz). In all its absorption frequency, the average of the acoustic absorption coefficient is over 0.9. Besides, the absorption coefficient can be tunable by the scalable cavity. The multilayer composite structure in our article solved the disadvantages in single material. For example, small absorption coefficient in low frequency in traditional material such as microperforated panel and porous material and narrow reduction frequency range in acoustic metamaterial such as Helmholtz cavity. The design of the composite structure in our article can have more wide application than single material. It can also give us a novel idea to produce new acoustic devices.

我们的工作研究了用于低频吸收领域的可调多层复合结构。该声学装置由三层组成，即亥姆霍兹腔层，微孔板层和多孔材料层。对于我们研究中的仿真和实验，吸收器可以满足两个方面的要求：在非常低的频率（400 Hz）下，吸声系数可以达到接近0.8，并且频率范​​围很广（400–3000 Hz）。在其所有吸收频率中，平均声吸收系数均超过0.9。此外，吸收系数可以通过可伸缩腔进行调节。本文中的多层复合结构解决了单一材料的缺点。例如，传统的材料（如微孔板和多孔材料）在低频下的吸收系数较小，而亥姆霍兹腔等声学超材料中的降低频率范围则较窄。本文中复合结构的设计可以比单一材料具有更广泛的应用。它也可以给我们一个新颖的想法来生产新的声学设备。