Aircraft element requiring an anti-frost treatment

Abstract

The present disclosure provides an aircraft element including a leading edge section and a trailing edge section, and the leading edge section includes an anti-frost treatment device. This aircraft element is remarkable in that the trailing edge section includes a superhydrophobic surface.

Claims

1. An aircraft nacelle comprising: a leading edge section including an air inlet lip that receives an anti-frost treatment device; and a trailing edge section downstream of the leading edge section, wherein the trailing edge section comprises at least one superhydrophobic surface that complements the anti-frost treatment device to reduce energy consumption of the anti-frost treatment device.

2. The aircraft nacelle according to claim 1, wherein the trailing edge section comprises a mid-section comprising an inner surface and an outer surface radially distant from said inner surface, said inner surface comprising at least one superhydrophobic surface.

3. The aircraft nacelle according to claim 2, wherein the outer surface further comprises said at least one superhydrophobic surface.

4. The aircraft nacelle according to claim 2, wherein the air inlet lip comprises at least one superhydrophobic surface.

5. The aircraft nacelle according to claim 4, wherein said at least one superhydrophobic surface of the air inlet lip is obtained through a chemical reaction between a fatty acid and said at least one superhydrophobic surface of the air inlet lip.

6. The aircraft nacelle according to claim 1, wherein said at least one superhydrophobic surface is obtained through a surface treatment method.

7. The aircraft nacelle according to claim 6, wherein said surface treatment method comprises pulverizing an organometallic complex.

Description

DRAWINGS

(1) In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

(2) FIG. 1 represents a propulsion unit known from the prior art; and

(3) FIG. 2 is a longitudinal sectional view of the air inlet lip of the nacelle and of a portion of the trailing edge section.

(4) The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

(5) The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

(6) In the present description, it is meant by aircraft element comprising a leading edge section and a trailing edge section, any element of an aircraft presenting an aerodynamic profile.

(7) As example, such an aircraft element may be constituted by the wings of an aircraft, the (horizontal and vertical) rear tail units, the nacelles of turbojet or turboprop engines.

(8) In the following description, reference will be made, as an illustrative and non-limiting example, to a nacelle for an aircraft turbojet engine.

(9) Referring to FIG. 1, which represents a propulsion unit 1. Such a propulsion unit comprises a pylon 3 on which a nacelle 5 supporting a turbojet engine 7, is suspended.

(10) The nacelle 5 comprises a leading edge section 9 constituted by an air inlet lip 10, and a trailing edge section 11 comprising a mid-section 13 of the nacelle constituted by a fixed cowl 15, and a downstream section 17 of the nacelle constituted by a cowl 19 which can accommodate thrust reversal means.

(11) Referring to FIG. 2, which schematically illustrates a longitudinal section of the air inlet lip 10 extended by the cowl 15 which comprises an inner surface 21 in contact with a cold air flow F passing through the nacelle, and an outer surface 23 radially distant with respect to said inner surface.

(12) As is represented, the air inlet lip 10 is typically separated from the fixed cowl 15 by an annular wall 25.

(13) The air inlet lip 10 receives an anti-frost treatment device (not represented), constituted, for example, by a pneumatic or electrical de-frost or anti-frost device.

(14) According to the present disclosure, the trailing edge section, comprising the cowl 15 and positioned downstream of the heat-treated nacelle area, is superhydrophobic.

(15) The superhydrophobic characterization of a material is made by measuring the contact angle between its planar surface and a water drop placed on its surface: standard materials have an angle smaller than 90, the hydrophobic materials have an angle comprised between 90 and 150 and the superhydrophobic materials have an angle greater than 150.

(16) More specifically, at least one portion of the inner surface 21 of the cowl 15 is superhydrophobic.

(17) The inner surface 21 of the cowl 15 of the nacelle is made superhydrophobic by any surface treatment method.

(18) As a non-limiting example, the method used for making the nacelle superhydrophobic comprises a method for pulverizing an organometallic complex over the surface to be treated.

(19) According to one variant, the outer surface 23 of the cowl 15 is also made superhydrophobic, for example, through said organometallic pulverization method. This allows making the nacelle compatible with an open rotor type turbojet engine, that is to say having an unducted fan at its downstream section.

(20) One form, the metallic air inlet lip 10 of the nacelle is also superhydrophobic. As previously, the air inlet lip may be made superhydrophobic by any surface treatment method.

(21) The outer surface 27 of the air inlet lip 10 may be treated by pulverizing an organometallic complex or may be made superhydrophobic through a reaction of a fatty acid and said outer surface 27. The superhydrophobic character of the air inlet lip allows using very advantageously a de-frost device through piezoelectric component.

(22) The de-frosting through piezoelectric component consists in making the surface to be de-frosted vibrate in order to break and remove the thin layers of ice accumulated on the lip.

(23) In particular, the de-frosting through piezoelectric component is described in further details in the European patent number EP 2 209 715 and belonging to the Applicant, the entire contents of which are incorporated herein in their entirety.

(24) Thus, the use of a superhydrophobic surface as a complement to a piezoelectric-type mechanical de-frost device allows facilitating the pulling-off of ice, in that the adhesive strength of ice on the wall of the element to be de-frosted is reduced.

(25) Whatever the methods for obtaining superhydrophobic surfaces, these surfaces are obtained through a surface treatment method. Unlike the hydrophobic coatings known from the prior art, this allows advantageously enhancing considerably the resistance to erosion of the treated surface and reducing substantially the cost of treating these surfaces.

(26) Thanks to the present disclosure, by providing for superhydrophobic surfaces as a complement to anti-frost treatment devices, the energy consumption of these anti-frost treatment devices is reduced considerably.

(27) Finally, it goes without saying that the present disclosure is not limited to the sole forms described above only as illustrative examples, but it encompasses, on the contrary, all variants involving the technical equivalents of the described means as well as their combinations if these are within the scope of the present disclosure.