The attenuation of the higher-order cross-section modes in a duct with a thin porous layer.
The attenuation of the higher-order cross-section modes in a duct with a thin porous layer.
复制标题
具有薄多孔层的管道中高阶横截面模式的衰减。
DOI：
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复制
发表时间：
2005
影响因子：
2.4
通讯作者：
K. Horoshenkov
中科院分区：
文献类型：
--
作者：
Y. Yin;K. Horoshenkov
本文研究了任意截面和边界条件的管道中高阶横截面模态声传播的数值方法。该方法假定管道的横截面是均匀的，并且管道具有相当长的长度，从而可以忽略纵向模式。问题被简化为一个二维（2D）有限元（FE）的解决方案，从一组横截面的特征值和特征函数的确定。该结果被用于获得模态频率、速度和衰减系数。二维有限元解决方案，然后扩展到三维通过正常模式分解技术。数值计算结果与实验数据进行了验证，在管道内壁部分覆盖粗砂或粒状橡胶的声传播。从建议的数值模型计算的本征频率的值进行验证，对那些预测的标准的分析解决方案，圆形和矩形管刚性壁。结果表明，所考虑的数值方法是有用的预测的声压分布，衰减，和本征频率在管道中的声学非刚性边界条件。这项工作的目的是铺平道路的发展，一个有效的反问题解决方案的远程表征的声学边界条件在自然和人工波导。
A numerical method for sound propagation of higher-order cross-sectional modes in a duct of arbitrary cross-section and boundary conditions with nonzero, complex acoustic admittance has been considered. This method assumes that the cross-section of the duct is uniform and that the duct is of a considerable length so that the longitudinal modes can be neglected. The problem is reduced to a two-dimensional (2D) finite element (FE) solution, from which a set of cross-sectional eigen-values and eigen-functions are determined. This result is used to obtain the modal frequencies, velocities and the attenuation coefficients. The 2D FE solution is then extended to three-dimensional via the normal mode decomposition technique. The numerical solution is validated against experimental data for sound propagation in a pipe with inner walls partially covered by coarse sand or granulated rubber. The values of the eigen-frequencies calculated from the proposed numerical model are validated against those predicted by the standard analytical solution for both a circular and rectangular pipe with rigid walls. It is shown that the considered numerical method is useful for predicting the sound pressure distribution, attenuation, and eigen-frequencies in a duct with acoustically nonrigid boundary conditions. The purpose of this work is to pave the way for the development of an efficient inverse problem solution for the remote characterization of the acoustic boundary conditions in natural and artificial waveguides.