US Patent 10961913 Acoustic liners for use in a turbine engine

An acoustic liner for a turbine engine, the acoustic liner includes a support layer that includes a set of partitioned cavities with open faces, a facing sheet operably coupled to the support layer such that the facing sheet overlies and closes the open faces, a set of perforations located in the facing sheet and in fluid communication with a corresponding one of the cavities to form a set of acoustic resonators, and at least a subset of the perforations have an axially-oriented, relative to the axial flow path, inlet.