航空发动机进气道声辐射模型解析与数值计算结果比较分析

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ACOUSTIC RADIATION MODELLING OF AEROENGINE INTAKE COMPARISON BETWEEN ANALYTICAL AND NUMERICAL METHODS
Stephane Lidoine,Herve Batard,Sophie Troyes and Alexia Delnevo
EADS Airbus SA, Departement d'acoustique
B.P. M01 32/7, F-31060 Toulouse, France

Michel Roger11
Laboratoire de Mecanique des Fluides et d'Acoustique - UMR CNRS 5509
Ecole Centrale de Lyon, F-69131 Ecully, France

Significant reduction of engine noise by nacelle acoustic treatment requires accurate numerical modelling of engine nacelle ducts. The present study consists in the validation of gradually complex and realistic approaches, able to account for scattering and flow effects. First, the analytical method, based on the modal theory and the Wiener-Hopf's technique, is considered here as a reference for the comparisons. A 3D variational integral approach is presented in the second part. Several comparisons and parametric studies show good agreements in canonical case at low frequencies, in the presence of uniform flow or acoustic liners. The main observable differences caused by the inlet lip thickness are highlighted and analysed. Finally, both analytical and integral approaches seem to be consistent and allow us to develop more complicated methods like FEM or Ray-tracing to improve the predictions.