Li Zhao, Jing Liwen, Murch Ross
Department of Electronic and Computer Engineering, the Hong Kong University of Science and Technology, Hong Kong, 999077, China.
J Acoust Soc Am. 2017 Dec;142(6):3564. doi: 10.1121/1.5016962.
Acoustic wave propagation (up to 50 kHz) within a water-filled high-density polyethylene (HDPE) pipeline is studied using laboratory experiments and theoretical analysis. Experiments were carried out in a 15 m length of cylindrical HDPE pipeline using acoustic transducers to acquire signals uniformly spaced along the axis of the pipe. By proposing the use of the iterative quadratic maximum likelihood algorithm to this experimental configuration, wavenumbers, attenuations, and mode amplitudes could be accurately extracted from the measurement data. To allow comparisons with theoretical analysis, dispersion curves of the wavenumbers, attenuations, and acoustic power characteristics of the axisymmetric and nonaxisymmetric modes are predicted by extending an existing waveguide model. The model extensions included the introduction of a monopole acoustic source into the water medium so that amplitude variations with respect to individual modes and frequencies could be investigated in detail. In addition, stiffness coefficients of HDPE material are carefully used to account for viscoelastic effects. The comparisons between the theoretical predictions and experimental results demonstrate a very good match and are a validation of the theoretical model.
利用实验室实验和理论分析，研究了声波在充满水的高密度聚乙烯（HDPE）管道内（高达50kHz）的传播情况。实验在一段15米长的圆柱形HDPE管道中进行，使用声学换能器沿管道轴线均匀间隔采集信号。通过对该实验配置提出使用迭代二次最大似然算法，可以从测量数据中准确提取波数、衰减和模式振幅。为了与理论分析进行比较，通过扩展现有的波导模型，预测了轴对称和非轴对称模式的波数、衰减和声学功率特性的色散曲线。模型扩展包括在水介质中引入单极声源，以便能够详细研究相对于各个模式和频率的振幅变化。此外，还仔细使用了HDPE材料的刚度系数来考虑粘弹性效应。理论预测与实验结果之间的比较显示出非常好的匹配，验证了理论模型。
