Reinforced acoustic treatment panel for an aircraft propulsion unit
An acoustic treatment panel intended to be disposed on at least one wall of an aircraft propulsion unit in contact with a fluidic flow, the panel including a first, acoustically reflective skin, a second, acoustically porous skin intended to be in contact with the fluidic flow, and a honeycomb structure extending between the first skin and the second skin and having a plurality of cavities. The panel includes at least one acoustically transparent reinforcing wall passing through a plurality of cavities of the honeycomb structure and extending from the second skin to the first skin, forming a non-orthogonal angle with the first and second skins.
1. An acoustic treatment panel intended to be disposed on at least one wall of an aircraft propulsion unit in contact with a fluid flow, the panel comprising a first acoustically reflective skin, a second acoustically porous skin intended to be in contact with a fluid flow, a honeycomb structure extending between the first skin and the second skin and comprising a plurality of cavities,
wherein it comprises at least one acoustically transparent reinforcing wall passing through a plurality of cavities of the honeycomb structure and extending from the second skin to the first skin forming a non-orthogonal angle with the first and second skins, said at least one reinforcing wall being formed in one piece with the first acoustically reflective wall.
2. The acoustic treatment panel according to claim 1 , wherein said at least one acoustically transparent reinforcing wall has a perforation rate greater than or equal to 18%.
3. The acoustic treatment panel according to claim 1 , wherein the honeycomb structure extends, in a plane parallel to the second skin, inside an outer perimeter, and said at least one reinforcing wall extends inside the honeycomb structure from the second skin to the first skin on a border portion of the honeycomb structure extending, in the plane parallel to the second skin, from said outer perimeter to the interior of the honeycomb structure.
4. The panel according to claim 1 , wherein the reinforcing wall comprises a fastening portion extending to the outside of the panel in the elongation of the second skin, the fastening portion being intended to be coupled to a wall of the propulsion unit.
5. The panel according to claim 1 , wherein the reinforcing wall comprises a fixing portion extending to the outside of the panel in the elongation of the first skin, the fixing portion being intended to be coupled to a wall of the propulsion unit.
6. The panel according to claim 1 , comprising at least one portion of panel extending, in a direction orthogonal to the first skin, between a reinforcing wall and a portion of the first skin, said at least one portion of panel being attached and fixed to the remainder of the panel by co-firing during the manufacture of the panel.
7. A propulsion unit intended to be mounted on an aircraft, the propulsion unit comprising at least one acoustic treatment panel according to claim 1 .
8. The propulsion unit according to claim 7 , comprising at least one air inlet provided with a front lip, an outer wall and an inner wall, and connected to one of said acoustic treatment panels forming at least one part of the inner wall.
9. The propulsion unit according to claim 8 , wherein said reinforcing wall of said acoustic treatment panel continues outside of said panel and is connected to the front lip of the air inlet.
10. An aircraft comprising at least one propulsion unit according to claim 6 .
11. A method for manufacturing an acoustic treatment panel intended to be disposed on at least one wall of an aircraft propulsion unit in contact with a fluid flow, the method for manufacturing the panel comprising a step of stacking a first acoustically reflective skin, a honeycomb structure and a second acoustically porous skin intended to be in contact with a fluid flow, the honeycomb structure extending between the first skin and the second skin and comprising a plurality of cavities,
wherein the method further comprises a step of installing at least one acoustically transparent reinforcing wall passing through a plurality of cavities of the honeycomb structure and extending from the second skin to the first skin forming a non-orthogonal angle with the first and second skins, said at least one reinforcing wall being formed in one piece with the first acoustically reflective wall.
12. The method according to claim 11 , comprising a step of producing at least one portion of panel intended to extend, in a direction orthogonal to the first skin, between a reinforcing wall and a portion of the first skin, and a step of connecting, by co-firing, said at least one portion of panel to the remainder of the panel.