A numerical method for vibro-acoustic problems with sheared mean flows

A model based on Galbrunʹs equation is proposed to address the problem of vibro-acoustic interactions in sheared flows. The use of a displacement-pressure mixed formulation of Galbrunʹs equation greatly simplifies the coupling condition formulations and avoids the problem of non-zero frequency spurious modes encountered with displacement-based acoustic formulations. This model is applied to duct acoustics. Comparisons with analytical models demonstrate the accuracy of the method. The effects of mean flow shear on acoustic wave propagation in elastic ducts are then illustrated.