声衬孔隙率对其吸声特性有着重要影响，且流向在提升工作效率方面也起到主要作用。为进一步探讨狭缝双层声衬吸声性能，应用COMSOL多物理场耦合软件对10种狭缝的组合进行研究，即改变狭缝的宽度以评估孔隙率$ \sigma_{i,} $对声衬声学特性的影响。结果表明，随着切向流速的增加，声衬的吸声性能逐渐降低，同时存在共振频率向高频漂移的现象，并且对于孔隙率较大的双层声衬而言，其在高流速作用下，会产生多个传输损失峰。内外孔隙率对声衬性能的影响不相上下，二者增加均会增强声衬的吸声性能。此外，对于孔隙率较大的双层声衬和较小的对称声衬，其所表现的吸声能力比同孔隙率单层声衬更强，这为在实际应用中选择参数合适的声衬提供了可靠的理论依据。
It has been shown in the literature that the porosity of the acoustic liner has an important influence on its sound absorption characteristics, and the flow direction also plays a major role in improving its working efficiency. In order to further explore the sound absorption performance of the slit double-layer acoustic liner, the COMSOL multiphysics coupling software is used to study the combination of 10 kinds of slits, that is, changing the width of the slits to evaluate the effect of porosity $\mathop \sigma \nolimits_{i,o} $on the acoustic properties of the acoustic liner. The results show that the sound absorption performance of the liner decreases with increasing the grazing flow velocity, while there is a phenomenon that the resonance frequency shifts to high frequencies. And for double-layered liners with larger porosity, multiple transmission loss peaks are generated at high flow velocity. The influence of internal and external porosity on the performance of acoustic liner is comparable, and the increase of both internal porosity and external porosity will enhance the sound absorption performance of acoustic liner. In addition, for double-layer acoustic liner with larger porosity and symmetrical acoustic liner with smaller porosity, their sound absorption capacity is stronger than that of single-layer acoustic liner with the same porosity. This work provides a reliable theoretical basis for the selection of a double-layer liner with suitable parameters for practical applications.
2023,45(20): 44-50 收稿日期：2022-9-26
DOI：10.3404/j.issn.1672-7649.2023.20.008
分类号：TB535
作者简介：杨兴林(1964-),男,博士,教授,研究方向为船舶轮机系统设计及性能优化
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