Air intake module for an aircraft turbomachine and its de-icing process

Abstract

An air intake module (1) for an aircraft turbomachine extending along a longitudinal axis (X) oriented upstream to downstream and comprising: - an inner wall (2) and an outer wall (3) together defining a channel (5) for the circulation of an airflow (F); - a plurality of airflow (F) guide vanes (14) extending radially in the channel (5) and each comprising a leading edge (BA) upstream; - at least one stator element (6) fixedly mounted on the inner wall (2) and on the outer wall (3) and extending radially in the channel (5) upstream of the guide vanes (14), the stator element (6) comprising an infrared wave emission device configured to emit an infrared (IR) beam on the leading edge (BA) of at least one of the guide vanes (14) to de-ice it. Figure from the summary: Figure 1

Description

Title of the invention: Air intake module for an aircraft turbomachine and its de-icing method Technical field

[0001] The present invention relates to the field of defrosting an air intake module of an aircraft turbomachine.

[0002] In a known manner, an aircraft turbomachine, such as a turboprop, comprises an air stream in which an air flow circulates from upstream to downstream. The turboprop conventionally comprises from upstream to downstream one or more compressors, a combustion chamber and one or more turbines. One of the turbines, in particular called a power turbine, is coupled in rotation to a propeller mounted at the upstream end of the turboprop, conventionally via a reduction gear. The propeller provides all or part of the thrust of the aircraft and is unducted, that is to say that the turboprop is free of a fairing extending around the rotating blades of the propeller.

[0003] In a known manner, the turboprop comprises a rectifier comprising stator vanes which extends to the inlet of the air stream to guide the air leaving the propeller into the stream. The admitted air is compressed in the compressor(s) each having one or more stages with a rotor and a stator. To adapt the flow of air admitted into the compressor according to the speed of the turboprop, an inlet guide wheel is conventionally mounted between the rectifier and the compressor(s). The inlet guide wheel comprises variable-pitch stator vanes, i.e. mounted to pivot radially to have a variable angle of inclination.

[0004] In practice, during the flight of an aircraft, due to the temperature and pressure conditions, ice is likely to form or even accumulate on the vanes of the rectifier, the inlet guide wheel or even the rotor of the upstream stage of the compressor. The accumulation of ice is undesirable because it can affect the aerodynamics and the distribution of mass around the axis of rotation of the turboprop. In addition, the detachment of a block of ice from the propeller can cause it to be ingested into the turboprop, which is likely to damage it. Turboprops are more exposed to ice than turbojets whose fan is ducted and allows, by centrifugal effect, to direct the supercooled water into the secondary vein and thus prevent the formation of ice in the primary vein.

[0005] To prevent the formation and / or accumulation of frost in turbojets, it is known from patent applications FR2986779A1 and FR3096657A1 to mount an infrared device in the nacelle to heat the walls of the air intake. Such a This solution increases the space requirement in the air inlet and the infrared radiation emitted is not suitable for reaching the blades located in the air stream of a turboprop, in particular those of the inlet guide wheel and the rotor of the upstream stage of the compressor.

[0006] The invention thus aims to eliminate at least some of these drawbacks. PRESENTATION OF THE INVENTION

[0007] The invention relates to an air intake module for an aircraft turbomachine, said air intake module extending along a longitudinal axis oriented from upstream to downstream and being configured to be mounted downstream of a propeller of the aircraft turbomachine, said air intake module comprising: • an inner wall and an outer wall, extending around the inner wall, together defining a circulation vein for an air flow, • a plurality of air flow guide vanes extending radially in the duct and each comprising an upstream leading edge, and • at least one stator member mounted fixedly on the inner wall and on the outer wall and extending radially in the vein upstream of the guide vanes.

[0008] The invention is remarkable in that said at least one stator member comprises an infrared wave emission device configured to emit an infrared beam on the leading edge of at least one of the guide vanes.

[0009] Thanks to the invention, the guide vanes located in the air stream can be de-iced efficiently and precisely using a low-energy infrared beam emitted directly within the air stream. The infrared wave emission device is advantageously integrated into the stator members present in the air stream, at the downstream end, so as not to disturb the flow of the air stream. This makes it possible to emit an infrared beam of direction and opening angle allowing precise and efficient de-icing of the leading edge of the guide vanes.

[0010] According to one aspect of the invention, said stator member or at least one of the stator members is in the form of a structural casing arm. The arms of the structural casing, by virtue of their dimensions and their structural function in the turbomachine, are advantageously adapted to receive the infrared wave emission device. In addition, the arms of the structural casing extend directly upstream of the blades of the inlet guide wheel, which allows localized defrosting, therefore precise and efficient, without risk of overheating.

[0011] According to one aspect of the invention, said stator member or at least one of the stator members is in the form of a stator blade. The stator blades are advantageously distributed over the entire circumference of the air stream, which allows the integration of a large number of infrared wave emission devices, each directed towards the leading edge of a small number of guide vanes.

[0012] According to one aspect of the invention, at least a portion of the guide vanes are inlet guide vanes, preferably mounted to pivot about a radial axis. The inlet guide vanes are exposed to frost, particularly in a turboprop where the propeller is unducted. Indeed, the supercooled water is not evacuated by centrifugal effect into a secondary vein as is the case in a turbojet with a fan.

[0013] According to one aspect of the invention, at least a portion of the guide vanes are compressor vanes, preferably rotor vanes of an upstream stage of the compressor. Such vanes are also subject to the risk of icing, particularly in a turboprop where the propeller is not shrouded. Indeed, the supercooled water is not evacuated by centrifugal effect into a secondary vein as is the case in a turbojet with a fan.

[0014] According to one aspect of the invention, the infrared wave emitting device is configured to emit a directional infrared beam oriented downstream having an opening angle of less than 150°. The infrared beam is preferably oriented along an axis parallel to the longitudinal axis. This makes it possible to direct the infrared radiation only onto the areas to be de-iced, namely the leading edge of the guide vanes. This makes it possible to limit energy consumption.

[0015] According to one aspect of the invention, the infrared wave emission device comprises an infrared wave source and a reflecting member mounted upstream of the infrared wave source, the reflecting member preferably being mounted concave with the concavity facing downstream. Preferably, the reflecting member is a metal wall, preferably polished. Advantageously, the reflecting member makes it possible to direct and concentrate the infrared beam on the areas to be de-iced, namely the leading edge of the guide vanes.

[0016] According to one aspect of the invention, the infrared wave emission device is configured to illuminate intermittently when the guide vanes pass through the area illuminated by the infrared beam. Intermittent lighting advantageously allows a reduction in energy consumption, while ensuring effective defrosting.

[0017] According to one aspect of the invention, the infrared wave emission device comprises an infrared wave source in the form of an electrically powered heating resistive member. Such an infrared wave source is advantageously efficient and economical.

[0018] According to one aspect of the invention, said at least one stator member comprises a downstream housing in which the infrared wave emission device is mounted for protect it and not disrupt the flow of air in the vein.

[0019] Preferably, the downstream housing comprises at least one translucent or transparent portion, which is advantageously adapted to transmit infrared radiation.

[0020] According to a preferred aspect, the downstream housing is open. This makes it possible to dispense with a translucent or transparent portion. The downstream housing can in particular be formed by the body of the stator member in a simple and practical manner.

[0021] According to another preferred aspect, the downstream housing is closed and thus comprises a trailing edge making it possible to preserve aerodynamics.

[0022] The invention also relates to an assembly of a propeller for an aircraft turbomachine and an air intake module as described previously, in which the air intake module is mounted downstream of the propeller.

[0023] The invention also relates to an aircraft turbomachine comprising a propeller and an air intake module as described above, in which the air intake module is mounted downstream of the propeller. The aircraft turbomachine is preferably in the form of a turboprop.

[0024] The invention also relates to a method for defrosting an air intake module as described previously, in which the infrared wave emission device of said at least one stator member emits an infrared beam on the leading edge of at least one of the guide vanes. PRESENTATION OF FIGURES

[0025] The invention will be better understood on reading the description which follows, given by way of example, and referring to the following figures, given by way of non-limiting examples, in which identical references are given to similar objects.

[0026] [Fig.l] is a schematic representation in longitudinal half-section of an air intake module of an aircraft turboprop according to one embodiment of the invention.

[0027] [Fig. 2] is a close-up schematic representation of [Fig. 1], in which an infrared wave emitting device is integrated into one or more housing structural arms for de-icing the leading edge of the inlet guide wheel blades.

[0028] [Fig. 3] is a schematic representation of an alternative embodiment of [Fig. 2], in which the infrared wave emitting devices also provide deicing of the leading edge of the rotor blades of the upstream stage of the compressor.

[0029] [Fig.4] is a schematic representation of an alternative embodiment of [Fig.2], in which an infrared wave emitting device is integrated into one or more rectifier vanes to de-ice the leading edge of the inlet guide vanes.

[0030] [Fig. 5] is a schematic representation of an alternative embodiment of [Fig. 2], in which infrared wave emitting devices are integrated in casing structural arms and in stator vanes to de-ice the leading edge of the inlet guide vanes and the rotor vanes of the upstream stage of the compressor.

[0031] [Fig. 6] is a schematic projection representation of the stator members and the guide vanes of the air intake module according to one embodiment of the invention.

[0032] [Fig.7] is a schematic perspective representation of a stator member according to a first embodiment of the invention.

[0033] [Fig.8] is a schematic perspective representation of a stator member according to a second embodiment of the invention.

[0034] It should be noted that the figures set out the invention in detail to implement the invention, said figures can of course be used to better define the invention where appropriate. DETAILED DESCRIPTION OF THE INVENTION

[0035] The invention relates to an air intake module configured to be mounted in an aircraft turbomachine, in particular a turboprop, and its deicing method.

[0036] As described previously and partially illustrated in [Fig. 1], an aircraft turbomachine, in particular a turboprop, conventionally comprises an air stream 5 in which an air flow F circulates from upstream to downstream. The turboprop conventionally comprises from upstream to downstream one or more compressors 17, a combustion chamber (not shown) and one or more turbines (not shown). One of the turbines, in particular called a power turbine, is coupled in rotation to a propeller 20 mounted at the upstream end of the turboprop, conventionally via a reduction gear (not shown). The propeller 20 provides all or part of the thrust of the aircraft and is unducted, that is to say that the turboprop is free of a fairing extending around the rotating blades of the propeller 20.

[0037] As previously described and illustrated in [Fig.l], the aircraft turboprop comprises a rectifier 12 comprising stator vanes extending at the inlet of the air stream 5 to guide the air flow F leaving the propeller 20 in the stream 5. The admitted air flow F is compressed in the compressor(s) 17 each comprising one or more stages with a rotor and a stator. To adapt the air flow admitted into the compressor 17 depending on the speed of the turboprop, the turboprop comprises an inlet guide wheel 15 mounted downstream of the rectifier 12 and upstream of the compressor(s) 17. The inlet guide wheel 15 comprises variable-pitch stator blades, i.e. mounted to pivot radially to have a variable angle of inclination.

[0038] As illustrated in [Fig.l], the aircraft turboprop also comprises a structural casing 13 comprising one or more structural arms extending into the air stream downstream of the rectifier 12 and upstream of the inlet steer wheel 15. The arms of the structural casing 13 typically provide passage for the wiring and the lubricating fluid. It goes without saying that the turboprop could not comprise a rectifier 12 or not comprise an inlet steer wheel 15.

[0039] According to the invention and as illustrated in [Fig.l], the air intake module 1 is mounted downstream of the propeller 20 along a longitudinal axis X and comprises: • an inner wall 2 and an outer wall 3, extending around the inner wall 2, together defining the air stream 5, • guide vanes 14 of the air flow F extending radially in the vein 5 and each comprising a leading edge BA ([Fig.2]) upstream exposed to frost, • one or more stator members 6 mounted fixedly on the inner wall 2 and on the outer wall 3 and extending radially in the vein 5 upstream of the guide vanes 14, one or more of the stator members 6 comprising an infrared wave emission device 8 (see [Fig.2]) configured to emit an infrared beam IR on the leading edge BA of one or more of the guide vanes 14 to de-ice them.

[0040] It is specified that the terms “upstream” and “downstream” are defined in relation to the circulation of the air flow F. The terms “interior” and “exterior” are defined radially in relation to the axis X of the air intake module 1.

[0041] As will be described below, the guide vanes 14 preferably designate the vanes of the inlet guide wheel 15 and / or the vanes of the rotor 16 of the upstream stage of the compressor 17 extending downstream of the inlet guide wheel 15. In addition, the stator member(s) 6 preferably designate one or more rectifier vanes 12 and / or one or more arms of the structural casing 13.

[0042] The guide vanes 14 in the air stream 5, in particular those of the inlet guide wheel 15 and / or rotor 16 of the compressor 17, are thus defrosted using one or more local infrared wave sources mounted directly in the air stream 5. The defrosting is advantageously efficient and energy-efficient. The infrared wave sources are advantageously integrated into the arms of the structural casing 13 and / or in the rectifier vanes 12 as close as possible to the guide vanes 14 to be defrosted.

[0043] As illustrated in [Fig.l], the air stream 5 is typically axisymmetric, delimited radially internally by the inner wall 2 and radially externally by the outer wall 3. The outer wall 3 comprises at its upstream end an air inlet lip 4 and is defined from upstream to downstream by the outer shroud of the rectifier 12, by the outer wall of the structural casing 13, by the outer shroud of the inlet guide wheel 15 and by the outer rotor wall 16 of the upstream stage of the compressor 17. The inner wall 2 extends downstream of the propeller 20 and more precisely in the downstream extension of the wall of the cone of the propeller 20. The inner wall 2 is defined from upstream to downstream by the inner shroud of the rectifier 12, by the inner wall of the structural casing 13, by the disc of the inlet guide wheel 15 and by the rotor disc 16 of the upstream stage of the compressor 17.

[0044] In the example of [Fig. 2], the infrared wave emission device 8 is integrated into one or more structural casing arms 13 at their downstream end so as to emit an infrared beam IR onto the leading edge BA of one or more blades of the inlet guide wheel 15. As illustrated in [Fig. 3], the infrared beam IR can alternatively or additionally be directed onto the leading edge BA of one or more blades of the compressor 17, and in particular those of the rotor 16 of the upstream stage which are most exposed to frost. These embodiments, where the arms of the structural casing 13 form the stator members 6, are particularly advantageous because the infrared source is thus located as close as possible to the guide vanes 14 to be defrosted. In addition, the structural casing arms 13 are adapted in terms of dimensions to integrate an infrared wave emission device 8.

[0045] In the example of [Fig. 4], the infrared wave emission device 8 is integrated into one or more blades of the rectifier 12 at their downstream end so as to emit an infrared beam IR on the leading edge BA of one or more blades of the inlet guide wheel 15. Alternatively or additionally, the infrared beam IR is directed onto the leading edge BA of one or more blades of the compressor 17, and in particular those of the rotor 16 of the upstream stage most exposed to frost. These embodiments, where the stator vanes 12 form the stator members 6, have the advantage of having a greater number of infrared sources distributed around the circumference of the air stream 5. As illustrated in [Fig. 5], infrared wave emission devices 8 can be integrated both in the stator vanes 12 and in the arms of the structural casing 13.

[0046] In the example of Figures 7 and 8, the infrared wave emission device 8 is mounted in a downstream housing 7, 7' of the stator member 6, whether it is a structural casing arm 13 or a rectifier blade 12. For this, the stator member 6 comprises a body 19 with a truncated downstream end and the downstream housing 7, 7' extends downstream of the body 19 (in place of the truncated downstream end). Alternatively, the body 19 of the stator member 6 comprises a downstream end and the downstream housing 7, 7' extends downstream of the downstream end of the body 19. The downstream housing 7, 7' may also be formed in whole or in part by the body 19 of the stator member 6 itself.

[0047] As illustrated in Figures 7 and 8, the downstream housing 7, 7' preferably extends in the downstream extension of the stator member 6 to preserve aerodynamics. In the example of [Fig.7], the downstream housing 7 is closed and comprises an aerodynamic trailing edge. Such a housing 7 comprises at least one translucent or transparent portion adapted to transmit at least in part the infrared beam IR emitted by the infrared wave emitting device 8. In the example of [Fig.8], the downstream housing 7' is open downstream, i.e. is free of a trailing edge. The opening makes it possible to dispense with translucent or transparent material to transmit the infrared beam IR.

[0048] As illustrated in Figures 7 and 8, the infrared wave emission device 8 comprises an infrared wave source 9 and, preferably, a reflective member 10 mounted upstream of the infrared wave source 9. The infrared wave source 9 is preferably in the form of an electrically powered heating resistive member, in particular emitting omnidirectional radiation. The infrared wave source 9 preferably extends over at least half of the radial height of the stator member 6, preferably over at least 75%, and even more preferably over substantially the entire radial height. In this example, the infrared wave source 9 is in the form of a filament, in particular of carbon, in the shape of an I comprising electrical power supply connectors 11 at its radially inner and outer ends.Alternatively, a U-shape with two power supply connectors 11 on the same radially inner or outer side may be used.

[0049] As illustrated in [Fig.6], the infrared wave emission device 8 is configured to emit a directional infrared beam IR oriented downstream, in particular along an axis substantially parallel to the longitudinal axis X, having a predetermined opening angle a. The reflecting member 10, preferably concave with concavity facing downstream, advantageously makes it possible to reflect the omnidirectional radiation emitted by the infrared wave source 9 so as to form the infrared beam IR. The reflecting member 10 is for example a metal wall, in particular polished. Alternatively or in a complementary manner, the dimensioning of the opening and / or of the translucent or transparent portion of the housing 7, 7' makes it possible to form the infrared beam IR.

[0050] The opening angle a is preferably less than 150°, defined in a plane tangential to the longitudinal axis X. A small opening angle a, for example example less than 90°, makes it possible to concentrate the irradiation on the leading edge BA of a single guide member 14-D, in the example of [Fig.6] from the stator member 6-B. A large opening angle a, for example between 90° and 150°, makes it possible to encompass the leading edge BA of several neighboring guide members 14, of the same type or not. In this example, the infrared wave emission device 8 integrated in the stator member 6-A makes it possible to irradiate several blades of the compressor 17, but also a blade of the inlet guide wheel 15. The infrared beam IR is continuous or intermittent, depending on the defrosting requirements.

[0051] According to an aspect illustrated in [Fig. 6], the infrared wave emission device 8 mounted in the stator member 6-C is configured to emit an intermittent infrared beam IR only when a rotor blade 16 of the compressor 17 passes through the area illuminated by the infrared beam IR. This makes it possible to synchronize the infrared lighting with the passage of the blade. The infrared wave emission device 8 is only lit when the rotor blade 16 passes through its lighting area, which reduces energy consumption. The lighting frequency is determined for example from the rotational speed of the rotor 16, in particular acquired by a measuring member 18 such as an optical, Hall effect, capacitive or inductive sensor.

[0052] The invention also relates to a method for defrosting the air intake module 1 during which each infrared wave emission device 8 emits an infrared beam IR onto one or more guide vanes 14 in the air stream 5. The defrosting can be triggered manually or automatically, continuously or intermittently. The infrared beam IR received on the leading edge BA of the guide vane 14 advantageously makes it possible to melt the frost present or to prevent its formation. The invention has the advantage of being energy-efficient and precise, thanks to infrared wave sources 9 mounted directly in the air stream 5 as close as possible to the guide vanes 14 to be defrosted.

Claims

Claims

1. Air intake module (1) for an aircraft turbomachine, said air intake module (1) extending along a longitudinal axis (X) oriented from upstream to downstream and being configured to be mounted downstream of a propeller (20) of the aircraft turbomachine, said air intake module (1) comprising: • an inner wall (2) and an outer wall (3), extending around the inner wall (2), together defining a vein (5) for circulation of an air flow (F), • a plurality of guide vanes (14) for the air flow (F) extending radially in the vein (5) and each comprising a leading edge (BA) upstream, • at least one stator member (6) fixedly mounted on the inner wall (2) and on the outer wall (3) and extending radially in the vein (5) upstream of the guide vanes (14),• said air intake module (1) being characterized in that said at least one stator member (6) comprises an infrared wave emission device (8) configured to emit an infrared beam (IR) on the leading edge (BA) of at least one of the guide vanes (14).,

2. An air intake module (1) according to claim 1, wherein said stator member (6) or at least one of the stator members (6) is in the form of a structural casing arm (13).

3. Air intake module (1) according to one of claims 1 and 2, wherein said stator member (6) or at least one of the stator members (6) is in the form of a vane of a rectifier (12).

4. Air intake module (1) according to one of claims 1 to 3, wherein at least a portion of the guide vanes (14) are vanes of an inlet steering wheel (15), preferably pivotally mounted along a radial axis.

5. Air intake module (1) according to one of claims 1 to 4, wherein at least a portion of the guide vanes (14) are vanes of a compressor (17), preferably rotor vanes of an upstream stage of the compressor (17).

6. Air intake module (1) according to one of claims 1 to 5, wherein the infrared wave emitting device (8) is configured to emit a directional infrared (IR) beam oriented downstream having an opening angle (a) of less than 150°.

7. Air intake module (1) according to one of claims 1 to 6, wherein the infrared wave emission device (8) comprises an infrared wave source (9) and a reflective member (10) mounted upstream of the infrared wave source (9), the reflective member (10) preferably being mounted concave with the concavity facing downstream.

8. Air intake module (1) according to one of claims 1 to 7, wherein the infrared wave emitting device (8) is configured to illuminate intermittently when the guide vanes (14) pass through the area illuminated by the infrared beam (IR).

9. Air intake module (1) according to one of claims 1 to 8, wherein said at least one stator member (6) comprises a downstream housing (7, 7') in which the infrared wave emission device (8) is mounted, the downstream housing (7, 7') preferably comprising at least one translucent or transparent portion.

10. Method for defrosting an air intake module (1) according to one of claims 1 to 9, wherein the infrared wave emission device (8) of said at least one stator member (6) emits an infrared beam (IR) on the leading edge (BA) of at least one of the guide vanes (14).

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