Broadband Acoustic Liner Based on the Mechanism of Multiple Cavity Resonance
Broadband Acoustic Liner Based on the Mechanism of Multiple Cavity Resonance
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DOI：
10.2514/1.27878
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发表时间：
2007-05
期刊：
影响因子：
2.5
通讯作者：
X. Jing;Xiaoyu Wang;Xiaofeng Sun
中科院分区：
文献类型：
--
作者：
X. Jing;Xiaoyu Wang;Xiaofeng Sun
本文提出了多腔共振机制，以扩大声衬垫的吸收带宽。其基本思想是，当衬垫的后腔被划分为不同大小的子腔时，会产生许多不同长度的共振，从而使吸声峰分布更加紧密，共同作用，在大带宽上提供高衰减。为了研究这一机制，首先建立了描述子腔内声模耦合效应的腔共振理论，并得到了多个共振频率的通式。此外，本文还建立了一个更严格的传播模型，该模型能够预测多共振声衬垫对管道内声音衰减的影响。并在无平均流量矩形风管的情况下进行了验证实验。与实验结果相比，理论能较好地预测谐振频率，而传播模型也能较好地预测传输损耗的大小。理论和实验结果都证明了该方法在提高声衬垫宽带性能方面的潜力。
In this paper the mechanism of multiple cavity resonance is proposed to broaden the absorption bandwidth of an acoustic liner. The basic idea is that, when the backcavity of the liner is divided into subcavities of different size, many resonances relating to different lengths are produced so that the peaks of sound absorption become more closely distributed and take effect jointly to afford high attenuation over a large bandwidth. To study this mechanism, a cavity-resonance theory is first established to describe the coupling effect of the acoustic modes inside the subcavities and arrives at a general formula for the multiple resonance frequencies. Furthermore, a more rigorous propagation model is developed that is capable of predicting the effect of a multiresonance acoustic liner on the sound attenuation in a duct. A verification experiment is also carried out in the situation of a rectangular duct without mean flow. When compared with the experiment, the theory well predicts the resonance frequencies, while the propagation model also gives reasonably good prediction for the magnitude of the transmission loss. Both the theoretical and experimental results demonstrate the potential of the present method in improving the broadband performance of an acoustic liner.