内置谐振器的轻薄宽频吸声器结构设计与分析*

微穿孔板吸声器的吸声频带相较于亥姆霍兹谐振器更宽，但其低频吸声的实现需要较大的空气背腔，这对结构尺寸有限制的场合存在一定局限性。本文设计了一种轻薄吸声降噪结构(内置亥姆霍兹谐振器的微穿孔板吸声器，简称MPPHR)，将微穿孔板吸声器与亥姆霍兹谐振器进行了结合，提升吸声器的低频吸声性能的同时兼具了微穿孔板宽带吸声的优点。首先基于微穿孔板和亥姆霍兹谐振器理论建立了等效电路模型并计算了结构的声阻抗。然后通过有限元对MPPHR的吸声特性进行了参数研究。最后验证了MPPHR的声阻抗模型和有限元仿真的准确性。研究结果表明：MPPHR结构拥有更宽吸声频带，厚度仅为30mm的MPPHR的半吸收频带可达1294Hz，相较于同等厚度下的微穿孔板吸声器宽近500Hz。此外，MPPHR拥有更好的低频吸声效率。

Structural design and analysis of thin broadband absorber with built-in Resonator

Micro-perforated panel (MPP) sound absorber has a wider absorption band compared to Helmholtz resonator (HR), but its low-frequency sound absorption implementation requires a larger air back cavity, it is a limitation for places with limited structural dimensions. For this reason, a thin type of noise reduction sound absorber that combines MPP with HR (MPPHR) is designed, which not only improves the low-frequency sound absorption performance, but also has the advantages of wide-band sound absorption of MPP. Firstly, based on the theory of MPP and Helmholtz resonator, the equivalent circuit model is established, and the acoustic impedance of the structure is calculated. Then, the MPPHR sound absorption characteristics were analyzed by finite elements method. Finally, the mathematical model and the finite element simulation results of MPPHR were verified through experiments. The results show that the MPPHR absorber has a wider absorption band. The MPPHR with a thickness of 30mm have a half absorption band of up to 1294 Hz, which is nearly 500 Hz wider than the equal thickness MPP. In addition, the MPPHR has better low frequency absorption efficiency.