Air intake lip for a nacelle of an aircraft propulsion assembly
An annular air intake lip for a nacelle of an aircraft propulsion assembly is provided. The annular lip can extend about an axis of revolution and include: an external annular wall, an internal annular wall, an upstream annular wall connecting the external and internal annular walls to define an annular cavity therebetween. At least part of the annular lip can include at least one heat transfer coating that is made from a carbon allotrope material.
1. An annular lip of an air intake for a nacelle of an aircraft propulsion assembly, the annular lip extending around an axis of revolution and comprising:
an external annular wall;
an internal annular wall;
an upstream annular wall connecting the external and internal annular walls; and
an annular cavity delimited by the external annular wall, the internal annular wall, and the upstream annular wall,
wherein at least a portion of the annular lip comprises at least one heat transfer coating which includes an allotropic carbon material, the allotropic carbon material being graphene,
wherein the at least one heat transfer coating is located on one or more portions of a surface of the annular lip,
wherein the at least one heat transfer coating covers one or more parts of the annular cavity to heat an area or areas subject to frost which are isolated from a heat source,
wherein the at least one heat transfer coating is on an internal surface of the annular cavity and on the area or areas not directly exposed to the hot source, and
wherein the at least one heat transfer coating is configured to absorb hot air flow of the hot source, the absorbed hot air flow configured to be diffused into, and thereby transfer heat to, the internal surface of the annular cavity and the area or areas subject to frost.
2. The annular lip of claim 1 , wherein at least a portion of the external annular wall and/or the internal annular wall comprises the at least one heat transfer coating.
3. The annular lip of claim 1 further comprising at least one annular acoustic panel which is located in the cavity and which extends around the internal wall, wherein the internal wall is perforated and includes holes opening into acoustic cells of the acoustic panel.
4. The annular lip of claim 3 , wherein the annular acoustic panel comprises at least one annular skin which envelops the acoustic cells, wherein at least a portion of the at least one annular skin and/or at least a portion of the acoustic cells comprise the at least one heat transfer coating.
5. The annular lip of claim 4 , wherein the at least one annular skin comprises an upstream end which is attached to at least one of the internal and upstream annular walls, and wherein at least a portion of the upstream end and/or at least a portion of the at least one of the internal and upstream annular walls includes the at least one heat transfer coating.
6. The annular lip of claim 4 , wherein the external and internal annular walls of the lip are further interconnected by a downstream annular wall, wherein the at least one annular skin comprises a downstream end which is attached to the downstream annular wall, and wherein at least a portion of this downstream annular wall and/or at least a portion of the downstream end includes the at least one heat transfer coating.
7. The annular lip of claim 3 , further comprising at least one first area facing the acoustic panel and/or at least second and third areas adjacent to the acoustic panel, wherein the at least one annular heat transfer coating covers at least one of the first, second, and/or third areas.
8. The annular lip of claim 3 , wherein the acoustic panel comprises a metal alloy, a composite, or a thermoplastic.
9. The annular lip of claim 1 , wherein the graphene has a thermal conductivity of up to 5000 W·m −1 ·K −1 .
10. The annular lip of claim 1 , wherein the at least one heat transfer coating has a thickness of less than 40 μm.
11. The annular lip of claim 1 , further comprising a de-icing device which is of the pneumatic or electric type and which is at least partly housed in the annular cavity.
12. The annular lip of claim 11 , wherein the pneumatic de-icing device is configured to emit a flow of hot air, and wherein the internal annular wall further comprises through orifices which are distributed around the axis and which are configured to allow the flow of hot air to pass outside the annular cavity.
13. An aircraft propulsion assembly, comprising a nacelle equipped with an annular lip of an air intake according to claim 1 .
14. A method for manufacturing an annular lip of an air intake according to claim 1 , wherein the method comprises the steps of:
producing an annular lip formed from all or part of at least one of the external, internal, and upstream annular walls; and
applying at least one heat transfer coating to the annular lip.
15. The method according to claim 14 , wherein the at least one heat transfer coating covers one or more parts of the cavity to heat the area or areas subject to frost which are isolated from the heat source.
16. The method according to claim 14 , wherein the at least one heat transfer coating is applied by anodizing sealing, surface treatment, bonding, spraying, or applying a doped coating.
17. The annular lip of claim 1 , wherein the graphene has a thermal conductivity from 800 and 5000 W·m −1 ·K −1 .
18. The annular lip of claim 1 , wherein the at least one heat transfer coating has a thickness from 1.0 μm to 40 μm.
19. The annular lip of claim 1 , wherein the at least one heat transfer coating is annular.
20. The annular lip of claim 1 , wherein the at least one heat transfer coating is formed of a plurality of sectors connected circumferentially end to end with respect to the axis of revolution of the annular lip.