Aerodynamic measurement device

Abstract

The present invention relates to an aerodynamic measurement device (10) comprising a body (14) comprising a surface of interest (20). The device (10) is characterised in that the surface of interest (20) comprises a conductive layer (32) configured to emit heat when an electric current is applied to this layer (32).

Description

[0001] TITLE: Aerodynamic Measuring Device

[0002] The present invention relates to an aerodynamic measuring device. Such a device is, for example, part of an aircraft or any other device exposed to aerodynamic flows, such as a wind turbine.

[0003] As is known in itself, to ensure its mission, an aircraft includes several measuring devices comprising parts that are flush with the surface or appendages that protrude from the skin of the aircraft.

[0004] These appendages or protruding parts belong, for example, to probes used to measure various aerodynamic parameters of the airflow surrounding the aircraft, such as total pressure, static pressure, temperature, slippage, or the angle of incidence of the airflow in the vicinity of the aircraft skin.

[0005] The aircraft may encounter harsh environmental conditions (icing, standing water, etc.). More specifically, ice can form on the aircraft's skin or appendages. Ice formation is particularly problematic for aerodynamic probes, whose profiles can be altered by ice and whose pressure ports can be obstructed. In some cases, ice can also block the movement of at least some of the probes' moving parts and / or cause measurement errors if the accretion is not symmetrical, for example. Measuring instruments mounted on pods can also be affected by ice formation.

[0006] The technical problem that this invention addresses is to prevent the formation of frost and to ensure de-icing on the surface of aeronautical measurement equipment.

[0007] Several state-of-the-art documents already address this issue, at least partially.

[0008] For example, document FR 2 833 347 describes a heating device for a total pressure probe, implemented using electrical resistors embedded in the appendages. More specifically, this type of probe consists of a mast supporting a tube closed at one end, called a Pitot tube. The probe is heated by means of a heating element in the form of a heating wire wound within the probe body, i.e., both in the mast and in the Pitot tube. The document proposes an electrical conductor made of an iron-nickel alloy coated with a mineral insulator such as alumina or magnesia. The insulator is itself coated, for example, with a nickel sheath, allowing the wire to be brazed to the probe body.However, this solution has limitations, as manufacturing the heating wire and assembling it in the probe requires a series of complex and costly operations. The wire's energy consumption also remains very high.

[0009] US patent 4,275,603 describes an alternative technique for heating a Pitot tube probe. Specifically, it describes the use of a heat pipe that supplies thermal energy around the Pitot tube. The return of the heat transfer fluid to a liquid state is ensured through a porous material. This allows the probe to be positioned in any possible orientation on the aircraft skin.

[0010] In practice, this solution offers no industrial advantage due to the difficulty of inserting a porous material into a probe. It also necessitates design modifications. Manufacturing such a probe is at least as complex as one using a heating wire.

[0011] Finally, document EP 3581 939 proposes the use of coatings with low ice adhesion, allowing ice to detach more easily from the surface. These coatings are applied to strategic areas where the risk of ice formation is highest. When combined with a heating system, they can reduce the electricity consumption of these systems.

[0012] However, this solution has limitations. It is not a self-contained system. Indeed, when a layer of ice forms, a supplementary heating system is still required for defrosting. Furthermore, these coatings are degraded by environmental conditions and their performance is significantly impacted, potentially even becoming less efficient than the substrate.

[0013] The present invention aims to overcome all the drawbacks of the prior art. More particularly, the invention aims to provide means for actively heating an aerodynamic measuring device that can be easily integrated into such a device and exhibit moderate power consumption, without significant degradation of its properties over time.

[0014] To this end, the invention aims at an aerodynamic measuring device comprising a body including a surface of interest; the device being characterized in that the surface of interest includes a conductive layer configured to emit heat when an electric current is applied to this layer.

[0015] According to other advantageous aspects of the invention, the device comprises one or more of the following features, taken individually or in any technically possible combination: - the conductive layer comprises a pair of contacts arranged at one periphery thereof and configured to apply an electric current to the conductive layer;

[0016] - the device further comprising a voltage generator configured to generate a potential difference across the contacts;

[0017] - the contacts are formed at least partially by electrodes and / or conductive ink;

[0018] - the conductive layer is formed of a conductive paint or ink and / or a conductive coating made of a conductive material such as graphene;

[0019] - the surface of interest further includes an insulating layer disposed between the conductive layer and a substrate forming at least partially the body, and configured to electrically insulate the conductive layer from the substrate;

[0020] - the substrate includes a surface treatment;

[0021] - the insulation notch is further configured to facilitate the attachment of the conductive layer;

[0022] - the device further comprising a protective layer disposed on the conductive layer and configured to protect the conductive layer and / or electrically insulate the conductive layer;

[0023] - the or at least one of said layers is applied by spraying;

[0024] - the device forming an aerodynamic measuring probe or a camera;

[0025] - the body protrudes from or is flush with an external surface of an aircraft.

[0026] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0027] - [Fig. 1] Figure 1 is a schematic view of an aerodynamic measuring device according to the invention, the device comprising a surface of interest;

[0028] - [Fig. 2] Figure 2 is a detailed schematic view of the surface of interest in Figure 1;

[0029] - [Fig. 3] Figure 3 is a detailed schematic view of the surface of interest in Figure 1, according to a different example from that in Figure 2.

[0030] Figure 1 illustrates an aerodynamic measuring device 10 according to the invention. This device can be used in any environment exposed to aerodynamic flows.

[0031] In the illustrated example, the aerodynamic measuring device 10 includes an aerodynamic measuring probe. However, in general, the aerodynamic measuring device 10 may include any other device, such as a camera, projecting from or flush with a surface exposed to aerodynamic flows. According to the illustrated example, the device 10 of the invention allows for the measurement of at least one of the physical values ​​related to the medium, such as total pressure, static pressure, angle of attack, temperature, speed, etc.

[0032] More specifically, device 10 may feature an anemobaroclinometric probe which can, for example, measure several of the aforementioned quantities.

[0033] The environment in which device 10 is exposed is in particular a freezing environment, that is to say an environment in which frost accretions are likely to form outside or inside the device.

[0034] Device 10 is advantageously mounted on the fuselage of an aircraft or on an external part of a wind turbine.

[0035] An aircraft is defined as any pilotable machine capable of moving through the air. Specifically, an aircraft can be an airplane, a helicopter, or a drone.

[0036] As illustrated in Figure 1, the device 10 comprises an internal part 12 and a body 14.

[0037] The internal part 12 includes an electronic module 16 enabling the operation of the device 10. The internal part 12 is advantageously located away from aerodynamic flows, for example in an internal part of the fuselage of the aircraft or wind turbine.

[0038] The body 14 includes an outer surface 17 exposed to aerodynamic flows. In some examples, the body 14 further includes an inner surface also exposed at least partially to aerodynamic flows.

[0039] The body 14 is for example fixed to an external surface of the aircraft fuselage or to an external surface of the wind turbine such as a blade.

[0040] The body 14 has or forms a movable or sensitive part that allows the necessary measurements to be taken when exposed to aerodynamic flows. For example, the electronic module 16 is capable of generating measurements (such as angle of attack) as a function of the position of the movable part. In the example in Figure 1, the body 14 has a wind vane for the angle of attack sensor. In other examples, the body 14 has a tube, for example a Pitot tube, mounted on a mast away from the aircraft fuselage. This tube has an opening that allows aerodynamic flows to pass through it, where the pressure can, for example, be measured using known techniques.

[0041] The body 14 includes a surface of interest 20 having a surface on which icing must be prevented. In various embodiments, the surface of interest 20 may correspond to all or part of the outer and / or inner surface of the body 14. For example, in the case of a wind vane, the surface of interest 20 may extend over all or part of an outer surface forming the upper and lower surfaces and / or a junction surface between the fixed and moving parts of the wind vane. In the case of a Pitot tube, the surface of interest 20 may extend over all or part of the inner surface of the Pitot tube in contact with the aerodynamic flow.

[0042] To prevent frost formation on the surface of interest 20, the device 10 includes heating means 30. The heating means 30 include a heating active part 32, a pair of contacts 34 arranged in contact with the heating active part 32 and a voltage generator 36 configured to generate a potential difference on the contacts 34.

[0043] The voltage generator 36 is, for example, integrated into the internal part 12 of the device 10. The operation of this voltage generator 36 can, for example, be controlled by the electronic module 16 as a function of, for example, a temperature measured locally near the surface of interest 20. The voltage generator 36 is, for example, connected to an external power supply and allows, for example, the generation of a voltage V between 12 V and 800 V on the contacts 34.

[0044] The contacts 34 are connected to the voltage generator 36 by electrical conduits extending at least partially from the internal part 12 to the body 14 of the device 10. The electrical conduits may be formed at least partially of electrical wires and / or conductive ink.

[0045] According to the invention, the active heating part 32 of the heating means 30 is formed by a conductive layer 32 of the surface of interest 20. This conductive layer 32 extends, for example, over substantially the entire surface of interest 20. Alternatively, the conductive layer 32 extends over at least 30%, preferably over at least 50%, advantageously over at least 60%, and even more advantageously over at least 70%, of the area of ​​the surface of interest 20.

[0046] The conductive layer 32 is, for example, formed from a conductive paint or ink, such as graphene ink, paint with conductive particles (carbon, for example), etc. Alternatively or in addition, the conductive layer 32 is formed from a conductive coating made of a conductive material such as graphene.

[0047] The surface of interest 20 and the different layers composing it are illustrated in more detail in Figure 2.

[0048] Thus, as shown in Figure 2, the contacts 34 are, for example, arranged on the periphery of the conductive layer 32. These contacts 34 are formed at least partially by electrodes and / or conductive ink. Furthermore, as also illustrated in Figure 2, the surface of interest 20 comprises an insulating layer 41 and a protective layer 42 arranged such that the conductive layer 32 lies between these layers 41 and 42. In some embodiments, only one of these layers 41 and 42 is present. According to still other embodiments, the surface of interest 20 lacks these layers 41 and 42.

[0049] Advantageously, each of the layers 41, 42 extends along the entire extent of the conductive layer 32. According to other embodiments, at least one of these layers 41, 42 extends partially along the conductive layer 32.

[0050] The insulating layer 41 is disposed between the conductive layer 32 and a substrate forming at least partially the body 14. In the example in Figure 2, the substrate is formed by the outer surface 17 of the body 14. In other examples, the substrate is formed at least partially by the outer surface 17 and / or the inner surface of the body 14. In the example in Figure 3, the outer surface 17 of the body 14 receives a surface treatment (e.g., sulfuric anodizing, electroless nickel plating, etc.) which then forms a treatment layer 43 disposed between the outer surface 17 and the insulating layer 41. In some examples, this treatment layer 43 can also provide electrical insulation, so the additional insulating layer 41 is not required.

[0051] The insulation layer 41 is configured to electrically insulate the conductive layer 42 from the substrate. Furthermore, the insulation layer 41 is configured to facilitate the adhesion of the conductive layer 32. Finally, in some examples, the insulation layer 41 also provides thermal diffusion. This may be necessary, for instance, when, in addition to heating the exterior, heat needs to be diffused into the interior of the device 10. In other examples, the insulation layer 41 provides thermal insulation between the conductive layer 32 and the substrate. The material of the insulation layer 41 can be chosen according to the nature of the substrate and / or the conductive layer 32 to ensure better adhesion and / or insulation (thermal and / or electrical) and / or thermal diffusion. In addition, the insulation layer 41 may have a texture adapted to allow the adhesion of the conductive layer 32.

[0052] The protective layer 42 is placed on the conductive layer 32 and configured to protect the conductive layer 32 and / or electrically insulate it from the outside. The material of the protective layer 42 can be chosen according to the nature of the conductive layer 32 to ensure better adhesion and / or insulation.

[0053] Each layer 32, 41, 42 is preferably deposited by spraying. Alternatively, at least one of these layers 32, 41, 42 is deposited by any other technique such as screen printing or immersion (deep coating), particularly for complex geometries (internal channels). It is also possible to produce such a multilayer system (i.e., the three layers 32, 41, 42) in the form of adhesive patches to be applied to the surface of interest.

[0054] The thickness of each layer 32, 41, 42 can be chosen according to the material used and / or the function performed by that layer. For example, the thickness of each layer 32, 41, 42 is between 0.015 µm and 150 µm.

[0055] During operation of the device 10, the electronic module 16 controls the voltage generator 36 based, for example, on an average temperature measured near the surface of interest 20 or by any other means. The voltage generator 36 then creates a potential difference across the contacts 34. This potential difference induces an electric current in the conductive layer 32, which emits heat. The heat is transferred externally via the protective layer 42 to defrost the corresponding area. In some cases, the heat is also transferred internally to the device 10, for example via the layer 41, which acts as a thermal diffuser.

[0056] It is therefore understandable that the present invention offers a number of advantages.

[0057] First, the invention can be implemented in a particularly simple manner since the conductive layer can be easily produced even on surfaces with complex geometries. Furthermore, because the conductive layer can extend over virtually the entire surface of interest, heating can be implemented efficiently, thereby reducing the electrical consumption of the heating elements. In addition, various protective measures (such as a protective layer) can be used to prevent the degradation of the conductive layer's properties over time.

Claims

DEMANDS 1. Aerodynamic measuring device (10) comprising a body (14) including a surface of interest (20); the device (10) being characterized in that the surface of interest (20) includes a conductive layer (32) configured to emit heat when an electric current is applied to this layer (32); the conductive layer (32) being formed of a conductive paint or ink and / or a conductive coating formed of a conductive material.

2. Device (10) according to claim 1, wherein the conductive layer comprises a pair of contacts (34) disposed at a periphery thereof and configured to apply an electric current to the conductive layer (32).

3. Device (10) according to claim 2, further comprising a voltage generator (36) configured to generate a potential difference on the contacts (34).

4. Device (10) according to claim 2 or 3, wherein the contacts (34) are formed at least partially by electrodes and / or conductive ink.

5. Device (10) according to any one of the preceding claims, wherein the conductive material forming said conductive coating is graphene.

6. Device (10) according to any one of the preceding claims, wherein the surface of interest (20) further comprises an insulation layer (41) disposed between the conductive layer (32) and a substrate forming at least partially the body (14), and configured to electrically insulate the conductive layer (32) from the substrate; advantageously, the substrate comprises a surface treatment.

7. Device (10) according to claim 6, wherein the insulation notch (41) is further configured to facilitate the attachment of the conductive layer (32).

8. Device (10) according to any one of the preceding claims, further comprising a protective layer (42) disposed on the conductive layer (32) and configured to protect the conductive layer (32) and / or electrically isolate the conductive layer (32).

9. Device (10) according to any one of the preceding claims, in which the or at least one of said layers (32, 41, 42) is disposed by spraying.

10. Device (10) according to any one of the preceding claims, forming an aerodynamic measuring probe or a camera.

11. Device (10) according to any one of the preceding claims, wherein the body (14) protrudes from or is flush with an external surface of an aircraft.

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