Universitéde Technologie de Compiègne, Laboratoire Roberval UMR 6253, BP 20529, 60205 Compiègne cedex, France.
J Acoust Soc Am. 2011 Jul;130(1):42-51. doi: 10.1121/1.3598451.
In the present work, the propagation of sound in a lined duct containing sheared mean flow is studied. Walls of the duct are acoustically treated with absorbent poroelastic foams. The propagation of elasto-acoustic waves in the liner is described by Biot's model. In the fluid domain, the propagation of sound in a sheared mean flow is governed by the Galbrun's equation. The problem is solved using a mixed displacement-pressure finite element formulation in both domains. A 3D implementation of the model has been performed and is illustrated on axisymmetric examples. Convergence and accuracy of the numerical model are shown for the particular case of the modal propagation in a infinite duct containing a uniform flow. Practical examples concerning the sound attenuation through dissipative silencers are discussed. In particular, effects of the refraction effects in the shear layer as well as the mounting conditions of the foam on the transmission loss are shown. The presence of a perforate screen at the air-porous interface is also considered and included in the model.
在本工作中，研究了含有剪切平均流的衬里管道中声音的传播。管道的壁面采用多孔弹性泡沫进行吸声处理。衬里中的弹性声波传播由 Biot 模型描述。在流域中，剪切平均流中的声传播由 Galbrun 方程控制。问题在两个域中都使用混合位移-压力有限元公式来解决。已经对模型的 3D 实现进行了演示，并在轴对称示例上进行了说明。针对含有均匀流的无限管道中模态传播的特殊情况，展示了数值模型的收敛性和准确性。讨论了通过耗散消声器衰减声音的实际示例。特别地，说明了剪切层中的折射效应以及泡沫的安装条件对传输损耗的影响。还考虑了多孔界面处的穿孔筛，并将其包含在模型中。
