A model of acoustic impedance of perforated plates with bias flow considering the interaction effect
A model of acoustic impedance of perforated plates with bias flow considering the interaction effect
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DOI：
10.1016/j.jsv.2007.02.001
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发表时间：
2007-06
影响因子：
4.7
通讯作者：
Seong-Hyun Lee;J. Ih;K. Peat
中科院分区：
文献类型：
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作者：
Seong-Hyun Lee;J. Ih;K. Peat
推导了偏流条件下多孔板声阻抗的数值模型，并考虑了孔板间的相互作用。将归一化阻抗除以孔口平均流动马赫数，表示为改变孔隙率和厚度半径比的斯特劳哈尔数的函数。预测模型是通过求解有限厚度隔板中孔口的不可压缩欧拉方程来实现的。还使用误差控制装置对声阻抗进行了实验测量。随着孔隙率的增加，由于相互作用的影响，孔口上的附着质量减少，电抗趋于减小。除观察到非线性效应外，该模型预测的声阻抗在很大的孔隙度范围内与实测值吻合较好。为了比较新的阻抗模型和两个没有考虑相互作用影响的模型的性能，分别使用了两个模型来评估穿孔挡板的传递损失。与以往的模型相比，用新的阻抗模型预测的传输损耗与实测值吻合得更好，特别是在高孔率和高频下。
A numerical model of the acoustic impedance of perforated plates under bias flow conditions was derived, with consideration given to the interaction effect between orifices. The normalized impedance divided by the mean flow Mach number of an orifice was expressed as a function of the Strouhal number varying the porosity and thickness-to-radius ratio. The prediction model was accomplished by solving the incompressible Euler equation for an orifice in a finite-thickness partition that spans a tube. The acoustic impedance was also measured experimentally using an error-controlled setup. As porosity increased, the reactance tended to decrease because the attached mass on the orifices is decreased by the interaction effect. The acoustic impedance predicted by the proposed model shows reasonable agreement with measured data over the wide range of porosity values tested, except where nonlinear effects are observed. For comparison of the performance of the new impedance model against two previous models that did not consider the interaction effect, each was used in the evaluation of the transmission loss of perforated baffles. The predicted transmission losses using the new impedance model agree better with the measured data than those using the previous models, in particular at high porosities and at high frequencies.