Institute of Sound and Vibration Research, University of Southampton, Hampshire, UK.
J Acoust Soc Am. 2011 Aug;130(2):695-706. doi: 10.1121/1.3598463.
This paper uses a finite element method (FEM) to compare predictions of the attenuation and sound speeds of acoustic modes in a fluid-filled pipe with those of the analytical model presented in the first paper in this series. It explains why, when the predictions of the earlier paper were compared with experimental data from a water-filled PMMA pipe, the uncertainties and agreement for attenuation data were worse than those for sound speed data. Having validated the FEM approach in this way, the versatility of FEM is thereafter demonstrated by modeling two practical applications which are beyond the analysis of the earlier paper. These applications model propagation in the mercury-filled steel pipework of the Spallation Neutron Source at the Oak Ridge National Laboratory (Tennessee), and in a long-standing design for acoustic sensors for use on planetary probes. The results show that strong coupling between the fluid and the solid walls means that erroneous interpretations are made of the data if they assume that the sound speed and attenuation in the fluid in the pipe are the same as those that would be measured in an infinite volume of identical fluid, assumptions which are common when such data have previously been interpreted.
本文使用有限元方法（FEM）将充满流体的管道中声学模式的衰减和声速预测与本系列第一篇论文中提出的分析模型进行比较。它解释了为什么当早期论文的预测与充水 PMMA 管的实验数据进行比较时，衰减数据的不确定性和一致性比声速数据差。通过这种方式验证了 FEM 方法的有效性，随后通过对两个超出早期论文分析范围的实际应用进行建模展示了 FEM 的多功能性。这些应用模型在橡树岭国家实验室（田纳西州）散裂中子源的充汞钢管和长期设计用于行星探测器的声学传感器的传播。结果表明，流体和固体壁之间的强耦合意味着，如果假设管道中流体的声速和衰减与在相同体积的无限流体中测量的声速和衰减相同，那么对数据的解释就会出现错误，这些假设在以前解释此类数据时很常见。
