阅读说明：本技术 包括具有进气管的短舱以增大反推力的涡轮喷射引擎 (Turbojet engine comprising a nacelle with an air intake for increasing the reverse thrust ) 是由 丹尼尔-西普里安·明库 简-洛伊克·赫尔维·勒科迪克斯 尼古拉斯·约瑟夫·西尔文 弗雷德里克· 于 2020-04-08 设计创作，主要内容包括：本发明公开了飞行器涡轮喷射引擎(1),其沿轴线X延伸并包括风扇和短舱,风扇被配置为提供反推力,短舱包括进气管(2),进气管(2)包括至少一个在伸出位置与缩回位置之间运动的偏转件(3,4,5),在伸出位置,偏转件(3,4,5)沿朝向轴线X径向向内的延伸方向或沿轴线X的纵向延伸方向从内壁(21)或从进气管唇缘(23)伸出,以促进反向气流(F-INV)从内壁(21)的分离(D),以增大反推力；在缩回位置,进气管(2)具有空气动力学轮廓,从而沿内壁(21)引导内部气流(F-INT),以增大推力。(The invention discloses an aircraft turbo-jet engine (1) extending along an axis X and comprising a fan configured to provide a reverse thrust and a nacelle comprising an air inlet duct (2), the air inlet duct (2) comprising at least one deflector (3, 4, 5) moving between an extended position, in which the deflector (3, 4, 5) protrudes from an inner wall (21) or from an air inlet duct lip (23) along a direction of extension radially inwards towards the axis X or along a longitudinal direction of extension of the axis X, to promote separation (D) of a reverse airflow (F-INV) from the inner wall (21) to increase the reverse thrust; in the retracted position, the air inlet tube (2) has an aerodynamic profile so as to direct an internal air flow (F-INT) along the inner wall (21) to increase the thrust.)

1. An aircraft turbojet engine (1) extending along an axis (X) oriented from upstream to downstream, the internal air flow (F-INT) of which flows from upstream to downstream in a thrust phase and the reverse air flow (F-INV) of which flows from downstream to upstream in a reverse thrust phase, the turbojet engine (1) comprising a fan (11) configured to provide reverse thrust and a nacelle comprising an air inlet duct (2), the air inlet duct (2) extending circumferentially around the axis (X) and comprising an inner wall (21) facing the axis (X) and configured to direct the internal air flow (F-INT) and the reverse air flow (F-INV) and an outer wall (22) opposite the inner wall (21) and configured to direct an external air flow (F-EXT), the inner wall (21) and the outer wall (22) being connected to one another by an air inlet duct lip (23), thereby forming an annular chamber (20), characterized in that it comprises deflection means comprising at least one deflector (3, 4, 5) moving between an extended position (a) in which said deflector (3, 4, 5) protrudes from said inner wall (21) or from said inlet duct lip (23) along a direction of extension (X3, X4) radially inwards towards the axis (X) or along a longitudinal direction of extension (X5) of the axis (X), so as to separate (D) said counter-flow (F-INV) from said inner wall (21) to increase the counter-thrust; in the retracted position, the intake tube (2) has an aerodynamic profile, so as to direct the internal air flow (F-INT) onto the inner wall (21) to increase the thrust.

2. The turbojet engine (1) of claim 1, wherein the direction of extension (X3, X4, X5) is upstream.

3. The turbojet engine (1) of claim 1 or 2, characterized in that the annular chamber (20) extends in a longitudinal direction (X20) parallel to the axis (X), and the extension directions (X3, X4) form an extension angle (a) with respect to the longitudinal direction (X20), the extension angle (a) being 90 ° -140 °.

4. The turbojet engine (1) of any one of claims 1 to 3, characterized in that the deflector means comprise a plurality of deflectors (3, 4, 5) circumferentially distributed on the intake pipe (2) about the axis (X).

5. The turbojet engine (1) of any one of claims 1 to 4, characterized in that the deflection means comprise at least one row of deflectors, each row of deflectors comprising a plurality of deflectors (3, 4, 5) equidistant from the axis (X) in a radial direction.

6. The turbojet engine (1) of any one of claims 1 to 3, characterized in that the deflector means comprise a single deflector (3, 4, 5) extending circumferentially about the axis (X).

7. The turbojet engine (1) of any one of claims 1 to 6, characterized in that at least one deflector (3) rotates between the extended position (A) and the retracted position (B).

8. The turbojet engine (1) of any one of claims 1 to 6, characterized in that at least one deflector (4, 5) moves between the extended position (A) and the retracted position (B) in the direction of extension (X3, X4, X5).

9. The turbojet engine (1) of any of claims 1 to 8, wherein the deflector means comprises at least one active drive member (33, 43, 53) for driving the deflector member (3, 4, 5) from the retracted position (B) to the extended position (A).

10. The turbojet engine (1) of any one of claims 1 to 9, characterized in that the deflector comprises at least one passive drive (34) configured to drive the deflector (3) from the retracted position (B) to the extended position (a) under the action of the reverse airflow (F-INV).

11. The turbojet engine (1) of any of claims 1 to 10, characterized in that the deflector comprises a cover (44) moving between a closed position (C1) and an open position (C2); in the closed position, the cover (44) covers the deflector (4) in the retracted position (B) to form an aerodynamic profile; in the open position, the cover (44) is biased away from a closed position (C1) to allow the deflector (4) to move to the extended position (a).

12. Method of using a turbojet engine (1) according to any of claims 1 to 11, characterized in that it comprises bringing at least one deflector (3, 4, 5) in the retracted position (B) during a thrust phase of the turbojet engine (1) so that the air intake pipe (2) has an aerodynamic profile to direct the internal air flow (F-INT) onto the internal wall (21); in a thrust reversal phase of the turbojet engine (1), the deflector (3, 4, 5) is driven to move to the extended position (A) so that the deflector (3, 4, 5) extends from the inner wall (21) or from the air inlet pipe lip (23) in a direction of extension (X3, X4) radially inwards towards the axis (X) or in a longitudinal direction of extension (X5) of the axis (X) to separate (D) the reverse air flow (F-INV) from the inner wall (21) to increase thrust reversal.

Technical Field

The present invention relates to the field of aircraft turbo-jet engines, and more particularly to air intake ducts of aircraft turbo-jet engine nacelles.

Background

As is known, an aircraft comprises one or more turbojet engines, so as to enable its propulsion to be achieved by accelerating the airflow flowing from upstream to downstream in the turbojet engine.

Referring to fig. 1, a turbojet engine 100 is shown, which extends along an axis X and comprises a fan 101 rotatably mounted in a casing 102 about the axis X so as to accelerate an air flow flowing from upstream to downstream in the turbojet engine 100, i.e. an internal air flow F-INT, during a thrust phase of the turbojet engine 100. Hereinafter, the terms "upstream" and "downstream" are defined with respect to the flow direction of the internal gas flow.

As known, the turbojet engine 100 comprises a nacelle comprising, at its upstream end, an air intake duct 200 comprising an inner wall 201 facing the axis X and an outer wall 202 opposite the inner wall 201. The inner wall 201 and the outer wall 202 are connected by an inlet pipe lip 203 comprising a leading edge, thereby forming an annular cavity 220. The inlet duct 200 has an aerodynamic profile for dividing the upstream air flow F into an inner air flow F-INT guided by an inner wall 201 and an outer air flow F-EXT guided by an outer wall 202. In the following, the terms "inner" and "outer" are defined with respect to the radial direction of the axis X of the turbojet 100.

In order to reduce the braking distance of an aircraft, in particular during landing, it is known to integrate a counterthrust system in the nacelle to change the direction of the airflow at the exhaust duct in order to generate the counterthrust. As is known, the thrust reversal phase is carried out by opening flaps and/or grilles in the secondary flow downstream of the straightener, so as to direct the flow of air back outwards in a radial manner with respect to the axis X or upstream.

For a large bypass ratio turbojet engine, the nacelle has a large diameter and it is not desirable to install a conventional thrust reversal system in an integrated manner, since this would have a significant adverse effect on the weight, overall size and drag of the turbojet engine.

In order to generate the thrust reversal, another solution consists in providing a variable pitch fan, or VPF, to reverse the flow of the air flowing in the secondary flow of the turbojet engine, so as to generate the thrust reversal to achieve the deceleration of the aircraft during landing or any other manoeuvre.

Referring to FIG. 2, during a reverse thrust phase, the reverse airflow F-INV flows downstream and upstream in the turbojet engine 100, i.e., in the opposite direction to the internal airflow F-INT of FIG. 1. More precisely, the reverse air flow F-INV flows near the casing 102 and is then directed axially upstream by the inner wall 201 substantially along the axis X. This reverse airflow F-INV is now opposite to the upstream airflow F, thereby generating a reverse thrust.

In fact, as shown in fig. 2, part of the reverse airflow F-INV may bypass the aerodynamic profile of the air intake tube 200 in a substantially radial direction, which may result in a local depression P near the air intake tube lip 203. This local depression P generates an upstream suction force, i.e. a force opposite to the thrust reversal. In fact, this phenomenon very significantly affects the performance of the thrust reversal phase.

The invention therefore aims to reduce this phenomenon in order to improve the performance of the turbojet engine in the reverse thrust phase, while not affecting the performance of said aircraft in the thrust phase (i.e. when the airflow is not reversed).

In the prior art, it is known from patent applications EP3421373a1 and US3770228a1 that the air intake duct comprises one or more outwardly pivoted members to prevent the separation of the internal air flow from the internal walls under adverse operating conditions, in particular during take-off. This component is not conducive to the thrust reversal phase.

From patent application US3736750a1 it is known that, in order to reduce the emitted noise, the air intake comprises a ring-shaped portion movable between cruise, take-off and landing conditions.

In the non-highly relevant field of hovercraft, from patent application GB1565212A a propeller mounted in a fairing, the shape of the upstream end of which can be changed by means of inflatable members, is known.

Disclosure of Invention

The invention relates to an air inlet duct for an aircraft turbojet engine nacelle extending along an axis X oriented from upstream to downstream, wherein an inner air flow flows downstream from upstream in a thrust phase and a counter air flow flows upstream from downstream in a counter-thrust phase, the air inlet duct extending circumferentially around the axis X and comprising an inner wall facing the axis X and configured to direct the inner and counter air flows and an outer wall opposite the inner wall and configured to direct an outer air flow, the inner and outer walls being connected to each other by an air inlet duct lip, thereby forming an annular chamber.

The invention is remarkable in that said intake duct comprises deflecting means comprising at least one deflector moving between an extended position and a retracted position:

-in said extracted position, said deflector protrudes from said inner wall or from said air inlet duct lip along a radially inward extension towards axis X or along a longitudinal extension of axis X, so as to effect the separation of said counter-flow from said inner wall to increase the thrust;

-in the retracted position, the air intake tube has an aerodynamic profile to direct the internal air flow on the inner wall to increase thrust.

By means of the invention, the reverse air flow is separated from the inner wall, thus preventing the reverse air flow from bypassing the lip, limiting the generation of local recesses in comparison with the prior art and thus generating a force opposing the thrust reversal. Furthermore, the performance of the turbojet engine in the thrust phase is not reduced. The deflector projects radially inwardly so that the reverse airflow is affected before contacting the lip of the air inlet conduit.

Preferably, the deflector is rigid. The rigid member is opposite the elastic cuff.

Preferably, the direction of extension is towards the upstream, in order to promote separation without reducing the forces in the counter-current air flow. Optionally, the direction of extension is downstream.

Preferably, said annular chamber extends along a longitudinal direction X20 substantially parallel to axis X, and said extension direction forms an extension angle with respect to said longitudinal direction X20, said extension angle being 90 ° -140 ° so as to promote separation without reducing the forces in the counter-current flow.

Preferably, the direction of extension is a function of the desired thrust reversal.

Preferably, said deflector means comprise a plurality of deflectors circumferentially distributed about the axis X on said inlet duct to reduce drag.

Preferably, said deflecting means comprise at least one row of deflecting members, each row comprising a plurality of deflecting members at equal radial distances from the axis X, so as to create a separation around the entire circumference of the axis X.

Preferably, the deflector means comprise a plurality of rows of deflectors, each row comprising a plurality of deflectors at equal radial distances from the axis X, to promote separation of the counter-current flows.

Preferably, the line deflector is circular with an axis X.

Preferably, the rows of deflectors are staggered to reduce weight and drag while promoting separation of the reverse airflow over the entire circumference of the air inlet duct. Preferably, the deflectors partially overlap in the azimuthal direction.

According to another preferred aspect, said deflector means comprise a single deflector extending circumferentially about the axis X, ensuring a uniform or non-uniform separation of the counter-current of air over the entire circumference of the lip of the air inlet duct.

Preferably, at least one deflector rotates between the extended position and the retracted position to enable free rapid switching from one state to the other.

Preferably, the inner wall comprises a recess configured to house the deflector in the retracted position, so that the air intake duct has the same aerodynamic profile as the prior art, so as not to reduce the performance of the turbo-jet engine during the thrust phase.

According to another preferred aspect, at least one deflector is movable in the extension direction between the extended position and the retracted position to enable free rapid switching from one state to the other.

Preferably, at least one deflector is polygonal or cylindrical in order to improve the aerodynamics of the lip during the thrust reversal phase, and thus to improve the performance of the aircraft during the thrust reversal phase.

According to a preferred aspect, the deflection means comprise at least one active drive in order to drive the deflection member from the retracted position to the extended position in a simple and quick manner.

Preferably, the active drive member drives the deflector member from the extended position to the retracted position to effect bi-directional movement from one state to the other in a simple and rapid manner.

According to another preferred aspect, the deflector comprises at least one passive drive configured to drive the deflector from the retracted position to the extended position under the action of the counter-current, without the need for additional force provided by the aircraft. The deflector is autonomous.

Preferably, the deflector is configured to move from the extended position to the retracted position under the action of the internal airflow without the need for additional force to be provided by the aircraft.

Preferably, the deflector comprises a cover movable between a closed position in which it covers the deflector in the retracted position, so as to provide an aerodynamic profile, and an open position; in the open position, the cover is biased away from the closed position to allow the deflector to move to the extended position. The cover acts as an extension of the inner wall during the thrust phase, so that the air inlet duct can maintain its aerodynamic profile and therefore does not reduce the performance of the aircraft during the thrust phase.

The invention also relates to an aircraft turbojet engine extending along an axis X oriented from upstream to downstream, wherein an internal airflow flows from upstream to downstream in a thrust phase and a reverse airflow flows from downstream to upstream in a reverse thrust phase, the turbojet engine comprising a fan configured to provide reverse thrust and a nacelle comprising an air intake duct as previously described, in order to increase the reverse thrust. Preferably, the fan comprises variable pitch blades.

The invention further relates to a method of using an air intake duct as described above, the method comprising, during a thrust phase of the turbojet engine, bringing at least one deflector in the retracted position so that the air intake duct has an aerodynamic profile to direct the internal air flow on the inner wall; in a thrust-back phase of the turbojet engine, the deflector is driven to move to the extended position, so that the deflector extends from the inner wall or from the air inlet pipe lip in a direction of extension radially inwards towards the axis X or in a longitudinal direction of extension of the axis X, so as to effect separation of the counter-flow from the inner wall to increase thrust-back.

Therefore, the intake pipe can be effectively used in the thrust phase and the reverse thrust phase. Further, the deflector can be moved easily and quickly. In addition, the number, shape, arrangement and movement of the deflection members allow the deflection device to be adapted to different operating conditions, such as braking.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments are briefly introduced below, wherein like reference numerals denote similar objects, and wherein:

FIG. 1 is a longitudinal cross-sectional schematic view of a prior art turbojet engine nacelle in the thrust phase;

FIG. 2 is a longitudinal cross-sectional schematic view of a prior art turbojet engine nacelle in the reverse thrust phase;

FIG. 3 is a schematic longitudinal cross-sectional view of a turbojet engine nacelle of the present invention in the reverse thrust phase;

fig. 4 and 5 are schematic transverse cross-sectional views of an air inlet tube according to the invention, the deflecting means of which comprise a row of deflecting members and two rows of deflecting members, respectively;

FIG. 6 is a transverse cross-sectional schematic view of an air induction tube of the present invention, the deflector of the air induction tube comprising a circumferential deflector;

FIGS. 7A and 7B are schematic longitudinal cross-sectional views of an air inlet tube including a deflector in an extended position and an air inlet tube including a deflector in a retracted position with an active drive, respectively, in accordance with a first embodiment of the present invention;

FIGS. 7C and 7D are schematic longitudinal cross-sectional views of an air inlet tube including a deflector in an extended position and a deflector in a retracted position with a passive drive, respectively, in accordance with a first embodiment of the present invention;

figures 8A and 8B are schematic longitudinal cross-sectional views of an air inlet tube comprising a deflector in an extended position and a deflector in a retracted position of a second embodiment of the invention,

FIG. 8C is a schematic longitudinal cross-sectional view of the air inlet conduit of the present invention including a deflector in a retracted position, the deflector including another cover;

FIGS. 9A and 9B are schematic longitudinal cross-sectional views of an air inlet tube including a deflector in an extended position and a deflector in a retracted position, respectively, according to a third embodiment of the present invention;

FIGS. 10A and 10B are schematic longitudinal cross-sectional views of a turbojet engine nacelle of the invention with non-uniform thrust reversal;

fig. 10C is a schematic transverse cross-sectional view of an intake pipe of the present invention that can achieve non-uniform reverse thrust.

It should be noted that the accompanying drawings illustrate the invention in detail for the purpose of practicing the invention, and can, of course, be used to better define the invention, if desired.

Detailed Description

With reference to fig. 3, a turbojet engine 1 of the invention is shown, extending along an axis X oriented from upstream to downstream and comprising a fan 11 rotatably mounted about the axis X in a casing 12 defining an air flow. As is known, the fan 11 is configured to accelerate, in a thrust phase, the air flow flowing from upstream to downstream in the turbojet engine 1, i.e. the internal air flow F-INT, and to accelerate, in a thrust phase, the air flow flowing from downstream to upstream in the turbojet engine 1, i.e. the reverse air flow F-INV.

In fact, as shown in FIG. 3, the reverse airflow F-INV flows downstream and upstream radially outward of the airflow, particularly at 1/3 beyond the airflow radius. The internal flow F-INT always flows from upstream to downstream radially inside the flow, particularly at 2/3, which exceeds the radius of the flow. The flow rate of the internal air flow F-INT is sufficiently fast to avoid any pumping phenomena of the turbojet engine.

As shown in fig. 3, the turbojet engine comprises a nacelle comprising, at its upstream end, an air inlet duct 2 extending circumferentially about the axis X, the air inlet duct comprising an inner wall 21 facing the axis X and configured to direct an inner air flow F-INT and an opposite air flow F-INV, and an outer wall 22 opposite the inner wall 21 and configured to direct an outer air flow F-EXT. The inner wall 21 and the outer wall 22 are connected by an inlet pipe lip 23 comprising a leading edge. The inner wall 21, the outer wall 22 and the inlet pipe lip 23 form an annular cavity 20 extending in a longitudinal direction parallel to the axis X. Within the annular cavity 20, sound attenuating devices or de-icing devices may be installed.

In the present embodiment, the turbojet engine 1 comprises thrust reversers, in particular variable pitch fans 11 or VPF, to reverse the flow of air flowing in the turbojet engine 1 and thus generate thrust reversals to achieve deceleration of the aircraft during landing or during any other manoeuvre.

According to the invention, with reference to figure 3, the intake pipe 2 comprises deflecting means comprising one or more deflecting members 3, 4, 5, which move between an extended position in which the counterthrust is increased and a retracted position in which the thrust is increased. Advantageously, in the extracted position, the deflectors 3, 4, 5 protrude from the inner wall 21 or from the intake duct lip 23, in a direction of extension radially inwards towards the axis X, or from the inner wall 21 or from the intake duct lip 23, in a direction of longitudinal extension of the axis X, to achieve a separation D of the reverse air flow F-INV from the inner wall 21, so as to favour the thrust reversal phase, as shown in fig. 3.

With reference to fig. 3, preferably, in the extended position, the deflectors 3, 4, 5 project from the inner wall 21 with respect to the axis X. Advantageously, the deflector 3, 4, 5 deflects the reverse air flow F-INV guided by the inner wall 21 so as to generate the separation D. In other words, the entire reverse airflow F-INV is directed so as to flow substantially in the axial direction with respect to the axis X so as to oppose the upstream airflow F, generating a reverse thrust. Preferably, the extension angle of the deflector members 3, 4, 5 is 90 ° -140 ° when the extension direction forms an extension angle with respect to the longitudinal direction of the annular chamber 20. Thus, the angle selected is small enough to promote separation D, and large enough not to significantly reduce the force in the reverse airflow F-INV. It goes without saying, however, that the extension angle may be different depending on the desired height of the thrust reaction. In particular, the deflectors 3, 4, 5 can also project downstream.

In the following, only a single deflecting means is presented, but it goes without saying that the air inlet tube 2 may comprise a plurality of deflecting means.

With reference to fig. 4, a deflector device is shown comprising a plurality of deflectors 3, 4, 5, which are circumferentially distributed on the inlet pipe 2 about the axis X in such a way as to be able to increase the thrust reversal over the whole of said circumference. With reference to fig. 4, in a preferred manner, the azimuthal length of the deflectors 3, 4, 5 is such that these surfaces are small in overall size, light and easy to extend. Naturally, the azimuthal length may vary between one deflector member 3, 4, 5 and another in order to accommodate different operating conditions, such as braking, and in particular to cope with uneven air flow over the circumference of the lip of the air inlet duct. Preferably, the azimuthal spacing between two consecutive deflectors 3, 4, 5 is sufficiently small that the deflectors 3, 4, 5 cover the maximum azimuthal surface area when protracted, or even partially overlap in the protracted position. Preferably, the number of deflectors 3, 4, 5 is sufficiently large to achieve a separation D over the entire circumference of the air inlet tube 2, and sufficiently small to reduce weight and drag.

Preferably, the deflectors 3, 4, 5 are arranged in rows. Preferably, each row of deflectors comprises a plurality of deflectors 3, 4, 5 radially equidistant from axis X. In other words, the rows are circular. For example, fig. 4 shows only one circular row and fig. 5 shows only two circular rows, but it goes without saying that the number of rows may be larger. Using several rows, in particular staggered rows as shown in fig. 5, it is possible to use deflectors 3, 4, 5 that are spaced apart from each other and easy to maintain to achieve a substantially continuous deflection along the circumference of the air inlet tube 2. In particular, the deflectors 3, 4, 5 may overlap in scale-like parts to form a continuity of deflection at the circumference of the air inlet tube 2.

Preferably, with reference to fig. 4, the ratio L3/L2 is between 0.05 and 0.3, wherein the parameter L3 is the radial thickness of the deflector 3, 4, 5 and the parameter L2 is the radial thickness of the air inlet tube 2.

Alternatively, with reference to fig. 6, the deflecting device comprises a single deflecting member 3, 4, 5 extending circumferentially about the axis X. This deflector 3, 4, 5 serves to ensure deflection over the entire circumference of the intake pipe 2 during the thrust reversal phase.

Preferably, the deflectors 3, 4, 5 project near the intake pipe lip 2 on the side of the inner wall 21, to avoid the formation of local depressions.

Preferably, the material of the deflectors 3, 4, 5 is rigid, so as to effectively increase the counterthrust. Preferably, this material is the same as the material of the inner wall 21 and/or the outer wall 22.

The invention will be better understood by describing different embodiments. The different aspects of the invention will be explained in succession hereinafter on the basis of three embodiments by way of example. It goes without saying that the invention is not limited to these three embodiments, but encompasses any possible combination of the various technical features of the embodiments set forth.

According to a first embodiment, with reference to fig. 7A and 7B, the deflecting device comprises a row of deflecting members comprising a plurality of deflecting members 3 radially equidistant from the axis X. In the present embodiment, each deflector 3 projects from the inner wall 21. Further, in the present embodiment, each deflector 3 includes a proximal end portion 31 that rotates between the extended position a and the retracted position B, and a distal end portion 32 adapted to deflect the reverse airflow F-INV.

In the present embodiment, the distal portion 32 is rectangular, although other shapes are suitable, particularly polygonal shapes such as trapezoidal. The advantage of the trapezoidal shape is that the distal portions together may cover the circumference of the air inlet tube continuously or substantially continuously when there is only one row of deflectors 3. The air flow is deflected over the entire circumference of the inlet pipe. In other words, a staggered arrangement of the deflectors 3 is not necessary for the trapezoidal shape.

Preferably, because the fan 11 includes fan blades, the length E3 of the distal portion 32 is less than 1/3 of the fan blade length. Preferably, the proximal end 31 is hinged at the inner wall 21 near the inlet tube lip 23.

In the present embodiment, as shown in fig. 7A, the inner wall 21 includes a recess 24 located upstream of the hinge axis of the deflector in the flow direction of the reverse airflow F-INV and configured to receive the deflector 3 located in the retracted position B. As shown in fig. 7B, in the retracted position B, the deflector 3 extends as an extension of the inner wall 21, so that the air inlet tube 2 has an aerodynamic profile.

In the example of fig. 7A, the extension angle α formed between the longitudinal direction X20 and the extension direction X3 of the annular chamber 20 is 90 ° -140 °, in which extension direction the deflector 3 in the extended position a is extended. Thus, it is advantageous that the selected stretching angle is small enough to promote separation D, and large enough not to significantly reduce the forces in the counter-current.

As shown in fig. 7A, in the extended position a, the reverse airflow F-INV generated by the fan 11 is directed by the inner wall 21 and then by the distal end portion 32 of the deflector 3, which directs the reverse airflow F-INV away from the air intake duct lip 23 to generate the separation D. This reduces the partial vacuum that occurs in the prior art, thereby improving the performance of the turbojet engine during the reverse thrust phase.

In the present embodiment, with reference to fig. 7A and 7B, the deflecting device comprises an active drive 33 for driving the deflecting member 3 from the retracted position B to the extended position a. This active drive 33 is, for example, in the form of a hydraulic, electric or other actuator, in order to drive the deflector 3 upon command of the controller. Preferably, the active drive 33 can also drive the deflector 3 from the extended position a to the retracted position B. Alternatively, during the thrust phase, the deflector 3 can also be moved passively from the extended position a to the retracted position B by the action of the internal air flow F-INT.

It goes without saying that the deflection device 3 may comprise a plurality of active drives 33.

According to another example, with reference to fig. 7C and 7D, the deflecting device comprises a passive drive 34 to drive the deflector 3 from the retracted position B to the extended position a without the aid of an actuator.

In the example shown in fig. 7C and 7D, the passive driver 34 is in the form of a conduit formed in the annular cavity 20 of the air inlet tube 2. Preferably, the duct comprises an inlet 34A leading to the inner wall 21 and an outlet 34B leading to the deflector 3 in the retracted position B. More precisely, the inlet 34A is located downstream of the deflector 3 with respect to the axis X. The inlet 34A may be located upstream or downstream of the fan. The outlet 34B in turn leads to the recess 24. Advantageously, the conduit can move the deflector 3 under the force generated by a portion F-INV1 of the reverse airflow F-INV flowing in the passive drive 34.

Advantageously, without providing a force to the passive drive 34, the deflector 3 is moved to the extended position a during the thrust phase by using the force of the counter air flow F-INV and to the retracted position B during the thrust phase by the force of the internal air flow F-INT.

It goes without saying that the passive drive 34 can have a different construction. It goes without saying that the deflection means may comprise a plurality of passive drives 34. Furthermore, the deflection device may comprise one or more passive drives 34 and one or more active drives 33.

According to a second embodiment illustrated in fig. 8A, 8B and 8C, a plurality of deflectors 4 are shown translating along the extension direction X4.

Preferably, the deflector 4 is polygonal, preferably trapezoidal, so as to have a high mechanical strength against the reverse air flow F-INV. Each deflector 4 extends from the inner wall 21 and includes a proximal end portion 41 and a distal flow deflector portion 42, similar to those described above. The proximal portion 41 extends in the annular cavity 20, while the distal portion 42 projects out of the annular cavity 20 in a radially inward extension direction X4 towards the axis X. Preferably, the length E4 of distal portion 42 is less than 1/3 of the fan blade length.

With reference to fig. 8A to 8C, the deflector 4 comprises a cover 44 moving between a closed position C1, in which the cover 44 covers the deflector 4 in the retracted position B, so as to form an aerodynamic profile (fig. 8B), and an open position C2; in the open position, the cover 44 is offset from the closed position C1 (fig. 8A and 8C) to allow the deflector 4 to move to the extended position a.

Preferably, the cover 44 is made of a rigid material. Preferably, the cover 44 is made of the same material as the inner wall 21 and is shaped as an extension of the inner wall 21, so that the aerodynamic profile of the air intake tube 2 remains unchanged during the thrust phase.

In the example of fig. 8A, the cover 44 translates inwardly along the inner wall 21 moving from the closed position C1 to the open position C2. In the example of fig. 8C, the cover 44 comprises two portions, radially internal and external, respectively, to the deflector 4, and rotatably hinged upstream of the intake pipe 2. It is understood, however, that the cover 44 may have other shapes and move in different manners. In addition, the cover 44 may include one or more portions. Furthermore, the movement of the covering 44 can be achieved by an active drive 43 and/or by a passive drive or any other drive.

According to a third embodiment, illustrated in fig. 9A and 9B, the deflecting device comprises a single deflecting member 5 extending circumferentially about the axis X. Advantageously, the reverse air flow F-INV is deflected over the entire circumference of the inlet pipe 2.

According to another aspect of the invention, as shown in fig. 9A and 9B, the deflector 5 is cylindrical and projects from the air intake lip 23 substantially along the longitudinal extension direction X5 of the axis X. Preferably, the deflector 5 extends the air inlet duct lip 23 and is therefore reduced in thickness, so as to promote the separation D of the reverse air flow F-INV. Preferably, the deflector 5 extends a length E5 less than 1/3 of the fan blade length.

Three specific embodiments of the present invention have been described by way of example, but it is to be understood that the present invention is not limited to these embodiments only. In fact, the invention covers any possible combination of different technical features of the described embodiments.

Specifically, all three embodiments described have the deflector to deflect the reverse airflow F-INV uniformly at the circumference of the intake pipe 2. However, under some operating conditions, such as braking, it may be advantageous to deflect this reverse airflow non-uniformly. Accordingly, various examples for unevenly deflecting the reverse airflow F-INV are described below with reference to fig. 10A to 10C.

As shown in fig. 10A, the deflectors 3, 4, 5 may be oriented in different directions at the circumference of the air inlet tube 2 so as to form an air inlet tube lip oriented towards the predetermined deformation axis AD. Alternatively, as shown in fig. 10B, the deflectors 3, 4, 5 may protrude by different lengths at the circumference of the air inlet tube 2. Furthermore, with reference to fig. 10C, the deflectors 3, 4, 5 may form rows of ellipses, in particular ovals, above the circumference of the air inlet tube 2 in a plane perpendicular to the axis X. In the case of a single deflector 3, 4, 5, it may take the form of an elliptical band in a plane perpendicular to the axis X. The uneven deflection advantageously makes it possible to direct the reverse air flow taking into account the environment of the inlet pipe 2.

The following describes a method of using the air inlet tube 2 according to the invention as described above.

During the thrust phase, the fan 11 can accelerate the internal air flow F-INT, which is guided by the intake duct 2 with an aerodynamic profile that promotes the thrust phase. During the thrust phase of the turbojet engine 1, the deflectors 3, 4, 5 are in the retracted position B, so that the intake pipe 2 has an aerodynamic profile in order to direct the air flow.

During the reverse thrust phase of said turbojet engine 1, in particular after a pitch change of the fan blades 11, the driving deflectors 3, 4, 5 move from the retracted position to the extended position a, during which the deflectors 3, 4, 5 are extended so as to project from the inner wall 21 or from the intake duct lip 23 in a radially inward direction of extension X3, X4 towards the axis X, or from the inner wall 21 or from the intake duct lip 23 in a longitudinal direction of extension X5 of the axis X, so as to increase the reverse thrust. Advantageously, this movement step gives the aircraft good performance both in the thrust phase, in which the internal airflow F-INT remains unchanged, and in the thrust phase, in which the deflectors 3, 4, 5 promote the separation D of the reverse airflow F-INV from the inner wall 21.

According to one aspect of the invention, during the movement step, only a portion of the deflector 3, 4, 5 is moved to adapt to different operating conditions, such as braking.

According to one aspect of the invention, the operating method comprises driving the deflector 3, 4, 5 in a simple and fast manner by means of the active drive 33, 43. According to another aspect of the invention, the method of operation includes driving the deflector 3, 4, 5 to the extended position a by means of the passive drive 34, cleverly using the force of the reverse air flow F-INV. Preferably, the passive drive 34 drives the deflector 3, 4, 5 to the retracted position B by using the force of the internal air flow F-INT.

Preferably, during the reverse movement, as the deflector 3, 4, 5 initially projects from the inner wall 21 or the intake pipe lip 23 along a direction of extension X3, X4 upstream and radially inwards towards the axis X, or from the inner wall 21 or the intake pipe lip 23 along a longitudinal direction of extension X5 of the axis X5, to increase the thrust reversal; the operating method comprises the step of driving the deflector 3, 4, 5 to move reciprocally from the extracted position a to the retracted position B, the deflector 3, 4, 5 being driven so that the air intake tube 2 has an aerodynamic profile that promotes a thrust phase. This movement may be performed actively or passively.

By means of the invention, the turbojet engine 1 significantly improves the performance of the reverse thrust phase while maintaining the existing performance of the thrust phase. In fact, the deflectors 3, 4, 5 in the extended position a promote the separation D of the reverse airflow F-INV from the inner wall 21, so that said reverse airflow F-INV is substantially axially opposite to the upstream airflow F, to generate a counterthrust, while reducing weight and resistance. In the retracted position B, the air inlet tube 2 advantageously maintains its aerodynamic profile.