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题名	高声强下多孔金属的吸声特性研究
作者	彭锋
学位类别	博士
答辩日期	2009-01-05
授予单位	中国科学院声学研究所
授予地点	声学研究所
关键词	多孔金属 高声强 吸声 噪声控制
其他题名	Investigation on Sound Absorption Characteristics of Porous Metals at High Sound Intensity
学位专业	声学
中文摘要	随着材料制备工艺的进步，多孔金属的轻质和多功能优点正引起各领域的关注。其中，通孔型多孔金属的吸声特性也成为噪声控制领域内的研究热点之一。作为被动式吸声材料，通过合理设计，多孔金属可实现宽频带、高吸声的优良特性。鉴于这些优点，在极端条件如高温、高声强环境下的噪声控制方面，多孔金属具有十分良好的应用潜力。本文主要以高声强下多孔金属材料的应用为研究背景，对其在相应条件下的吸声特性开展了理论与实验研究。主要工作如下： （1）针对高声压级下有限厚度多孔金属板在线性阻抗背衬条件下（背衬表面声压与声质点速度为线性关系）的吸声问题，提出了可描述不同声压级下材料层法向吸声性能的一维模型，并给出求解材料内部声质点速度的线化差分方法，以用于预测多孔金属板在高声压级下的非线性吸声性能。刚性背衬时，本文预测结果与文献结果对比符合良好。通过量纲分析，采用无量纲控制参数进行讨论，得到了关于多孔材料层声传播和吸声的一些基本非线性特性。 （2）在阻抗管中，对实际多孔金属板在空腔背衬、不同声压级下进行了测试，得到了材料法向表面阻抗和吸声系数随入射声压级变化的实验结果，其与理论预测结果对比符合良好，进一步验证了本文所提模型与数值方法的正确性。考虑高声强下应用多孔金属层吸声时，本文提出了设计准则。 （3）为研究穿孔面板覆盖多孔金属层在高声强下的吸声特性，提出了可预测高声压级下结构表面法向声阻抗的方法，并与实际两种复合结构在共振频率附近的实验结果对比，二者吻合较好，验证了预测方法。对复合结构在宽带噪声、不同总声压级激励下进行了实验，结果显示，多孔金属层和穿孔面板参数经过合适选择，不仅在线性条件可具有宽带高吸收的特性，在很宽的声级范围内也可实现稳定的宽频带、高吸声的性能。针对该类复合结构，本文提出了设计准则。
英文摘要	With the development of technology, porous metals have attracted attention from both academic and industrial sectors because of their light-weight and multi-functional characteristics. In noise control, the sound absorption of open-cell porous metals has become a research hotspot. As passive absorbing materials, they could be used for wideband and high absorbing performance. In addition to this, they have potentials for the application under extreme conditions, such as high temperature and high sound intensity. In this dissertation, both theoretical and experimental researches have been conducted on sound absorption characteristics of porous metals at high sound intensities. The main contents are as follows: (1) A one-dimensional model is proposed for sound absorption of a porous metal plate with finite thickness at high sound pressure levels (SPLs), where the sound pressure is linear with the particle velocity at the back of the plate. In order to predict nonlinear acoustic performance, the particle velocity inside the porous plate is solved by a linearization and finite difference method. Comparison of results between this work and published literature shows good agreement. Through dimensional analysis, some basic nonlinear characteristics of sound propagation and absorption of porous layers have been obtained. (2) Acoustic measurement at various SPLs for a porous metal plate backed by a cavity was performed in an impedance tube. The normal surface impedance and sound absorption coefficient at various SPLs were obtained. The model is validated by good agreement between the experimental and theoretical results. For sound absorption applications of porous metal layers under high sound intensity, guidelines are presented. (3)To investigate sound absorption characteristics of a porous layer covered by a perforated facing at high sound intensity, a method to predict the surface impedance of the construction is presented. The theoretical calculation shows good agreement with experimental results at resonance frequencies. Experiments under wideband noise excitation at various SPLs were performed. The results show that by properly choosing parameters, porous metal layers with perforated facings can have high sound absorption performance at a wideband of frequencies. This can be achieved not only under linear conditions but also nonlinear conditions of a wide range of high sound intensities. Guidelines for designing this construction are also presented.
语种	中文
公开日期	2011-05-07
页码	139
内容类型	学位论文
源URL	[http://159.226.59.140/handle/311008/150]
专题	声学研究所_声学所博硕士学位论文_1981-2009博硕士学位论文
推荐引用方式 GB/T 7714	彭锋. 高声强下多孔金属的吸声特性研究[D]. 声学研究所. 中国科学院声学研究所. 2009.

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