发动机圆形管道内噪声衰减谱模态分析

Modal analysis of sound attenuation spectra in a circular engine duct

本文应用模态分析方法建立了剪切流存在条件下，发动机多段声衬圆形管道声传播工程计算模型，对管内各模态频谱和总噪声衰减频谱进行了算例计算，并与有关文献试验数据进行了对比．结果表明：多段声衬圆形管道中声传播工程计算方法是可行的，从而为发动机前短舱管内声传播研究提供了一种模态分析工程预测方法．

By means of the mode analysis method, the engineering predicting models of sound propagation in a circular duct with segmented liners in the presence of shear flow are established. The sound attenuation spectra of the each circumferential mode based on a number of radial modes as well as the total sound sound attenuation spectrum based on the all radial modes and the spinning modes have been determined. In addition, the comparisons of the predicted sound attenuation and the test data provided in the relative references are presented. As a result, the engineering prediction method of sound propagation and attenuation in the lined circular ducts developed in this paper is feasible. Therefore, the engineering modal analysis methods is provided for the studies on the sound propagation in the front duct of engine nacelle.