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.