Acoustic treatment made by additive manufacturing
An acoustic treatment for use in an acoustic treatment for a gas turbine engine includes a sheath having a plurality of perforations. A plurality of cell structures extends from the sheath such that the sheath and the cell structures are a monolithic component. The plurality of perforations of the sheath are formed by filaments of a first material that define a first dimension of the perforations having a linear edge and filaments of a second material crossing the filaments of the first material that define a second dimension of the perforations having a linear edge. Such perforations have a non-cylindrical shape defined by the linear edges of the filaments of the first material and the filaments of the second material. A gas turbine engine is also disclosed.
1 . An acoustic treatment for use in an acoustic treatment for a gas turbine engine comprising:
a sheath having a plurality of perforations;
a plurality of cell structures extending from the sheath such that said sheath and said cell structures are a monolithic component, wherein the plurality of perforations of the sheath are formed by filaments of a first material that define a first dimension of the perforations having a linear edge and filaments of a second material crossing the filaments of the first material that define a second dimension of the perforations having a linear edge, such perforations having a non-cylindrical shape defined by the linear edges of the filaments of the first material and the filaments of the second material;
wherein the perforations of the sheath are aligned to be spaced apart from a wall of the cell structures; and
wherein strong areas of additional strength in at least one of said sheath and said plurality of cell structures are provided by in-fill materials added into a base material.
2 . The acoustic treatment as set forth in claim 1 , wherein the infill materials include chopped fibers.
3 . The acoustic treatment as set forth in claim 2 , wherein the chopped fibers include synthetic fibers.
4 . The acoustic treatment as set forth in claim 1 , wherein the infill materials include a continuous fiber.
5 . The acoustic treatment as set forth in claim 1 , wherein the infill materials include beads.
6 . A gas turbine engine comprising:
a fan delivering bypass air into a bypass duct defined in part by a fan case as bypass air, a fan duct surrounding said fan;
the fan also delivering core air into a compressor section, and the compressor section delivering air into a combustor, a turbine section mounted downstream of said combustor to receive products of combustion and to drive the fan and a compressor rotor;
there being an interior surface of said fan case, and the interior surface including an acoustic treatment having a cell with the acoustic treatment having a sheath having a plurality of perforations;
a plurality of cell structures extending from the sheath such that said sheath and said cell structures are a monolithic component, wherein the plurality of perforations of the sheath are formed by filaments of a first material that define a first dimension of the perforations having a linear edge and filaments of a second material crossing the filaments of the first material that define a second dimension of the perforations having a linear edge, the plurality of such perforations having a non-cylindrical shape defined by the linear edges of the filaments of the first material and the filaments of the second material;
wherein strong areas of additional strength in at least one of said sheath and said plurality of cell structures are provided by in-fill materials added into a base material;
wherein distinct radial areas are defined within a radial thickness of the sheath, and the material of the acoustic treatment including different characteristics in different areas; and
wherein there being areas of increased strength with lower strength in other areas.
7 . The gas turbine engine as set forth in claim 6 , wherein the open cells are generally rectangular.
8 . The gas turbine engine as set forth in claim 6 , wherein the open cells are honeycombed shape.
9 . The gas turbine engine as set forth in claim 6 , wherein the sheath is formed by the filaments including a plurality of filament portions extending along at least a first axis of a three-dimensional space, and others of the filaments crossing the first plurality of filaments and extending in a direction with at least a component along second and third axes in the three-dimensional space.