Nacelle air intake and nacelle comprising such an air intake
An air intake for a nacelle for an aircraft engine includes a front lip connecting a substantially cylindrical internal wall and a substantially cylindrical external wall, and at least one acoustic structure including acoustic cells. The acoustic structure is situated in the space delimited by the internal wall, the external wall and the front lip. The acoustic structure is an added part secured to the air intake. The acoustic cells of the acoustic structure are arranged facing a region of the internal wall or of the lip at a predetermined distance so that the acoustic cells of the acoustic structure are not in contact with the internal wall or the lip while providing an acoustic attenuation function.
1. An air intake for an aircraft engine nacelle, the air intake including:
an inner wall;
an outer wall;
a front lip connecting the inner wall and the outer wall; and
at least one acoustic structure comprising acoustic cells, the at least one acoustic structure being located in a space delimited by the inner wall, the outer wall and the front lip,
wherein the at least one acoustic structure is fixed to the air intake, the acoustic cells of the at least one acoustic structure being arranged facing an area of the inner wall and/or the front lip at a predetermined distance configured so that the acoustic cells of the at least one acoustic structure are not in contact with the inner wall and/or the front lip,
wherein the predetermined distance separating the acoustic cells from said area of the inner wall and/or the front lip is 1.5 mm.
2. The air intake according to claim 1 , wherein the at least one acoustic structure is fixed at a downstream end on at least one of an angle iron, a flange, and a partition.
3. The air intake according to claim 2 , wherein the at least one acoustic structure is mounted in cantilever with respect to the angle iron, flange, or partition.
4. The air intake according to claim 1 , wherein the at least one acoustic structure is fixed at an upstream end with at least one of the inner wall and the front lip.
5. The air intake according to claim 1 , wherein the at least one acoustic structure has a cellular structure and an acoustically resistive skin.
6. The air intake according to claim 5 , wherein the at least one acoustic structure is formed from a metal alloy.
7. The air intake according to claim 5 , further comprising a seal, wherein an upstream end of the at least one acoustic structure comprises a tab formed in an upstream extension of the acoustically resistive skin, wherein the seal is interposed between the tab and the front lip.
8. The air intake according to claim 1 , wherein the at least one acoustic structure is formed by at least one of brazing, additive manufacturing, stamping, forming of inserts, molding, and injection.
9. The air intake according to claim 1 , further comprising a de-icing system configured so as to guide air flow through at least one of orifices located upstream of the at least one acoustic structure, perforations of the inner wall, and the front lip in an area located facing the at least one acoustic structure forming a perforated skin for said acoustic structure.
10. The air intake according to claim 1 , wherein the at least one acoustic structure is fixed to the air intake by at least one of rivets, welding, and gluing.
11. A nacelle for an aircraft engine comprising an air intake according to claim 1 .
12. A method for manufacturing an air intake according to claim 1 , the method comprising:
manufacturing the front lip and all or part of the inner and/or the outer walls;
manufacturing the at least one acoustic structure; and
assembling the at least one acoustic structure with said manufactured wall forming the front lip and all or part of the inner and/or outer walls.
13. An air intake for an aircraft engine nacelle, the air intake including:
an inner wall;
an outer wall;
a front lip connecting the inner wall and the outer wall; and
at least one acoustic structure comprising acoustic cells, the at least one acoustic structure being located in a space delimited by the inner wall, the outer wall and the front lip,
wherein the at least one acoustic structure is fixed to the air intake, the acoustic cells of the at least one acoustic structure being arranged facing an area of the inner wall and/or the front lip at a predetermined distance configured so that the acoustic cells of the at least one acoustic structure are not in contact with the inner wall and/or the front lip, and
wherein the predetermined distance separating the acoustic cells from said area of the inner wall and/or the front lip is large enough to inhibit contact of the acoustic cells with the inner wall and/or the front lip and small enough to produce Helmholtz resonance in the acoustic cells.
14. The air intake according to claim 13 , wherein the predetermined distance separating the acoustic cells from said area of the inner wall and/or the front lip is 1.5 mm.
15. An air intake for an aircraft engine nacelle, the air intake including:
an inner wall;
an outer wall;
a front lip connecting the inner wall and the outer wall; and
at least one acoustic structure comprising acoustic cells, the at least one acoustic structure being located in a space delimited by the inner wall, the outer wall and the front lip,
wherein the at least one acoustic structure is fixed to the air intake, the acoustic cells of the at least one acoustic structure being arranged facing an area of the inner wall and/or the front lip at a predetermined distance configured so that the acoustic cells of the at least one acoustic structure are not in contact with the inner wall and/or the front lip,
wherein the predetermined distance separating the acoustic cells from said area of the inner wall and/or the front lip is less than 1.5 mm.