剪切流圆管物理参量对声衰减量的影响

应用模态分析方法建立了均匀流和剪切流条件下，发动机多段声衬圆形管道声传播工程计算模型，围绕各种物理参量如平均流Ｍａｃｈ数、附面层厚度和声衬腔深、声阻、面板特征频率、管长等对管内噪声衰减量的影响进行了算例计算，并与有关文献实验测量结果进行了验证对比，从而为发动机前短舱管内声传播研究提供了一种比较完整的模态分析工程预测方法。

EFFECTS OF PHYSICAL PARAMETERS OF CIRCULAR DUCT IN SHEAR FLOW ON SOUND ATTENUATION

Engineering prediction models of sound propagation in a circular duct with segmented liners in uniform flow and shear flow are established by means of the modal analysis method.The effects of the physical parameters,such as boundary layer thickness,mean flow Mach number,acoustic resistance,characteristic frequency of the facing sheet,cavity depth,and duct length on the in-duct sound attenuation have been determined for a numerical example.In addition,the test data of total sound attenuation in a duct with flow,published by other authors,have been used to verify the feasibility of the engineering prediction method provided.