Numerical and Experimental Study of Sound Power Reduction Performance of Acoustic Black Holes in Rectangular Plates
Numerical and Experimental Study of Sound Power Reduction Performance of Acoustic Black Holes in Rectangular Plates
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DOI：
10.4271/2015-01-2270
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发表时间：
2015-06
期刊：
影响因子：
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通讯作者：
Oliver Unruh;Christopher Blech;H. Monner
中科院分区：
文献类型：
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作者：
Oliver Unruh;Christopher Blech;H. Monner
结构速度的全局衰减是减少汽车顶盖或飞机机身面板等外壳结构发出的噪音的最有效方法之一。这种整体减少可以通过应用被动阻尼处理来实现，例如在大部分振动表面上施加约束层阻尼。这种方法的主要缺点是它导致总成本和结构重量的增加。为了克服这个问题，声学黑洞可用于创建具有高振动幅度和低弯曲波速的位置，以便通过非常有限的阻尼处理应用来耗散结构声的能量。声学黑洞是漏斗形的厚度减少，吸引声音辐射弯曲波，并允许通过可接受的附加阻尼的使用来减少整体振动。本文介绍了位于矩形板上的声学黑洞的数值和实验研究结果。目前的工作重点是声学黑洞的大小、位置和数量对声学性能的影响。通过有限元分析研究了这些参数的大量不同配置，并根据振动幅度和声功率级进行了评估。为了确认模拟结果，在实验室设置中实施最有效的配置，并根据振动和声学性能进行表征。
Global attenuation of structural velocities is one of the most effective approaches in order to reduce noise emitted by shell structures such as a car roof or aircraft fuselage panels. This global reduction can be achieved by the application of passive damping treatments like constraint layer damping on large fractions of the vibrating surface. The main disadvantage of this approach arises from the fact that it leads to increasing total cost and weight of the structure. To overcome this problem, acoustic black holes can be used to create locations with high vibration amplitudes and low bending waves velocity in order to dissipate the energy of structure borne sound by very limited application of damping treatments. Acoustic black holes are funnel shaped thickness reductions that attract sound radiating bending waves and allow a global vibration reduction by an acceptable use of additional damping. This paper presents the results of a numerical and experimental study of acoustic black holes located on a rectangular plate. The presented work is focused on the influence of size, position and number of acoustic black holes on the acoustic performance. A large number of different configurations of these parameters is studied by finite-element-analysis and evaluated in terms of vibration amplitude and sound power level. In order to confirm simulation results the most efficient configuration is implemented in laboratory setup and characterized in terms of vibrational and acoustic performance.