Abstract: An acoustic liner is provided. The acoustic liner includes a face sheet, a back sheet spaced from the face sheet, and a core layer defining a cellular structure disposed between the face sheet and the back sheet. The core layer includes a plurality of first resonant cells coupled to the back sheet. Each of the first resonant cells includes a first cell wall coupled to the back sheet along a first cell wall base edge, the first cell wall extending from the back sheet toward the face sheet, the first cell wall further coupled to the face sheet along a first cell wall top edge, wherein the first cell wall of each of the first resonant cells comprises a surface extension that extends from a surface of the first cell wall.

Abstract: An acoustic liner may include an acoustic core having an array of resonant cells, and an acoustic screen disposed across the array of resonant cells. The resonant cells include a plurality of cell walls and a resonant space defined by the plurality of cell walls. The acoustic core may include a folded acoustic core. Additionally, or in the alternative, at least some of the resonant cells may include an oblique polyhedral cellular structure and/or a multitude of sound-attenuating protuberances. The acoustic screen may include a reticulate membrane and a support lattice.

Abstract: An acoustic liner is provided. The acoustic liner includes a face sheet, a back sheet spaced from the face sheet, and a core layer defining a cellular structure disposed between the face sheet and the back sheet. The core layer includes a plurality of first resonant cells coupled to the back sheet. Each of the first resonant cells includes a first cell wall coupled to the back sheet along a first cell wall base edge, the first cell wall extending from the back sheet toward the face sheet, the first cell wall further coupled to the face sheet along a first cell wall top edge, wherein the first cell wall of each of the first resonant cells comprises a surface extension that extends from a surface of the first cell wall.

Abstract: An acoustic liner and a method of attenuating noise are provided. The acoustic liner includes a face sheet, a back sheet spaced from the face sheet, and a core layer extending between the face sheet and the back sheet. The core layer includes a plurality of resonant cells, each resonant cell including at least one cell wall coupled to the back sheet along a cell wall base edge. The at least one cell wall extends from the back sheet at an angle toward the face sheet. The at least one cell wall further coupled to the face sheet along a cell wall top edge. The resonant cell is formed in a predetermined shape and contains a volume in a space defined by the at least one cell wall, the back sheet, and the face sheet. The cell wall base edge length is greater than the cell wall top edge length.

Abstract: An acoustic liner (20) with perforation (30) and method of constructing (100) an acoustic liner including forming perforations in the facing sheet by grit blasting (104) the facing sheet and mounting (106) the facing sheet to one side of a support layer having a set of partitioned cavities wherein the facing sheet closes an open face of the cavities except for the perforations to form a set of acoustic resonator cells.

Abstract: 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.

Abstract: An acoustic liner may include an acoustic core having an array of resonant cells, and an acoustic screen disposed across the array of resonant cells. The resonant cells include a plurality of cell walls and a resonant space defined by the plurality of cell walls. The acoustic core may include a folded acoustic core. Additionally, or in the alternative, at least some of the resonant cells may include an oblique polyhedral cellular structure and/or a multitude of sound-attenuating protuberances. The acoustic screen may include a reticulate membrane and a support lattice.

Abstract: 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 perforated sheet that includes a set of perforations with corresponding inlets, the perforated sheet supported by the support layer such that perforations are in overlying relationship with the open faces to form paired perforations and cavities that define acoustic resonator cells, and a coating applied to the perforated sheet.

Abstract: An acoustic liner and a method of attenuating noise are provided. The acoustic liner includes a face sheet, a back sheet spaced from the face sheet, and a core layer extending between the face sheet and the back sheet. The core layer includes a plurality of resonant cells, each resonant cell including at least one cell wall coupled to the back sheet along a cell wall base edge. The at least one cell wall extends from the back sheet at an angle toward the face sheet. The at least one cell wall further coupled to the face sheet along a cell wall top edge. The resonant cell is formed in a predetermined shape and contains a volume in a space defined by the at least one cell wall, the back sheet, and the face sheet. The cell wall base edge length is greater than the cell wall top edge length.

Abstract: An acoustic liner and a method of attenuating noise are provided. The acoustic liner includes a face sheet, a back sheet spaced from the face sheet, and a core layer extending between the face sheet and the back sheet. The core layer includes a plurality of resonant cells, each resonant cell including at least one cell wall coupled to the back sheet along a cell wall base edge. The at least one cell wall extends from the back sheet at an angle toward the face sheet. The at least one cell wall further coupled to the face sheet along a cell wall top edge. The resonant cell is formed in a predetermined shape and contains a volume in a space defined by the at least one cell wall, the back sheet, and the face sheet. The cell wall base edge length is greater than the cell wall top edge length.

Abstract: A single degree of freedom (SDOF) acoustic liner includes a porous face sheet, a substantially imperforate back sheet generally parallel to and opposing said porous face sheet and defining a thickness therebetween, and an acoustic core layer of contiguous adjacent resonant cavities disposed between the porous face sheet and the imperforate back sheet. The acoustic core layer includes a first resonant cell having a first internal volume therein and a second resonant cell having a second internal volume therein different than the first internal volume. A cell partition wall extends between the porous face sheet and the imperforate back sheet, and separates and seals the first resonant cell from the second resonant cell. In a thickness direction, and perpendicular to a plane generally parallel with the porous face sheet and the substantially imperforate back sheet, the first internal volume overlaps the second internal volume over the cell partition wall.

Abstract: An acoustic liner and a method of attenuating noise are provided. The acoustic liner includes a face sheet, a back sheet spaced from the face sheet, and a core layer extending between the face sheet and the back sheet. The core layer includes a plurality of resonant cells, each resonant cell including at least one cell wall coupled to the back sheet along a cell wall base edge. The at least one cell wall extends from the back sheet at an angle toward the face sheet. The at least one cell wall further coupled to the face sheet along a cell wall top edge. The resonant cell is formed in a predetermined shape and contains a volume in a space defined by the at least one cell wall, the back sheet, and the face sheet. The cell wall base edge length is greater than the cell wall top edge length.

Abstract: An acoustic liner (20) with perforation (30) and method of constructing (100) an acoustic liner including forming perforations in the facing sheet by grit blasting (104) the facing sheet and mounting (106) the facing sheet to one side of a support layer having a set of partitioned cavities wherein the facing sheet closes an open face of the cavities except for the perforations to form a set of acoustic resonator cells.

Abstract: 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 perforated sheet that includes a set of perforations with corresponding inlets, the perforated sheet supported by the support layer such that perforations are in overlying relationship with the open faces to form paired perforations and cavities that define acoustic resonator cells, and a coating applied to the perforated sheet.

Abstract: 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.

Abstract: A single degree of freedom (SDOF) acoustic liner includes a porous face sheet, a substantially imperforate back sheet generally parallel to and opposing said porous face sheet and defining a thickness therebetween, and an acoustic core layer of contiguous adjacent resonant cavities disposed between the porous face sheet and the imperforate back sheet. The acoustic core layer includes a first resonant cell having a first internal volume therein and a second resonant cell having a second internal volume therein different than the first internal volume. A cell partition wall extends between the porous face sheet and the imperforate back sheet, and separates and seals the first resonant cell from the second resonant cell. In a thickness direction, and perpendicular to a plane generally parallel with the porous face sheet and the substantially imperforate back sheet, the first internal volume overlaps the second internal volume over the cell partition wall.