AIR INLET OF A TURBINE DRIVE NONSUBE WITH A CHANNEL FOR CIRCULATING A HOT AIR FLOW BETWEEN A MOVING UPWARD CURRENT SECTION AND A STATIONARY DOWNWARD CURRENT SECTION

Description

Domaine technique

[0001] The present invention relates to the field of aircraft turbomachinery and more particularly to a de-icing, or anti-icing, device for an air intake of a nacelle of an aircraft turbomachine.

[0002] As is known, an aircraft incorporates one or more turbomachines to provide propulsion by accelerating an airflow that circulates from upstream to downstream within the turbomachine. A turbomachine includes a nacelle to optimize the airflow circulating inside and outside the turbomachine.

[0003] With reference to the [ Fig.1 [ ] A turbomachine 100 is shown extending along an X-axis and comprising a fan (not shown) mounted to rotate about the X-axis in order to accelerate an airflow F from upstream to downstream. Hereafter, the terms upstream and downstream are defined with respect to the X-axis oriented from upstream to downstream. Similarly, the terms inside and outside are defined radially with respect to the X-axis of the turbomachine 100.

[0004] The turbomachine 100 has a radially external nacelle which includes an air inlet 102 extending upstream of the fan. This air inlet 102 separates the incoming airflow F into an internal airflow FINT, which is accelerated by the fan, and an external airflow FEXT, which is guided externally to the nacelle.

[0005] It is known that during aircraft flight, due to temperature and pressure conditions, frost can accumulate at the air intake, forming blocks that can be ingested by the turbomachine 100. Such ingestion must be prevented to improve the lifespan of the turbomachine 100 and avoid malfunctions. To prevent frost accumulation, a de-icing device is known to be provided in the annular cavity of the air intake 102.

[0006] As is known, for certain supersonic aircraft, it is desirable to modify the shape of the air intake 102 to adapt to the various flight regimes (high engine flow at low speed, low flow at high speed, etc.). For this purpose, with reference to figures 1 et 2 An air inlet 102 has been proposed, comprising a movable upstream part 102a connected to a fixed downstream part 102b by several controllable movement elements 104 so as to define: a PR retracted position ([ Fig.1 ]) in which the movable upstream part 102a is adjacent to the fixed downstream part 102b in order to form a continuous air inlet 102; an outlet position PS ([ Fig.2 ]) in which the movable upstream part 102a is separated from the fixed downstream part 102b in order to form a discontinuous air inlet 102.

[0007] Due to the discontinuity, in the PS outlet position, an airflow through FAT can circulate between the mobile upstream part 102a and the fixed downstream part 102b of the air inlet 102, which improves the capture of air at low speed.

[0008] In the retracted position (PR) and the extended position (PS), it is necessary to defrost the upstream moving part 102a, which is in contact with the outside airflow (FEXT). Integrating a defrosting circuit between parts 102a and 102b of the air inlet 102 is complex and increases the mass of the air inlet 102.

[0009] Prior art patent application GB850691A discloses an air inlet comprising controllable displacement mechanisms for a movable upstream portion of the air inlet. The air inlet also includes a defrosting circuit with a plurality of circulation pipes for conveying hot air to the movable upstream portion. Each circulation pipe is a telescopic tube comprising an inner cylinder mounted inside an outer cylinder. The outer cylinder extends from the hot air source to the fixed downstream portion and has a large diameter to allow passage of an inner cylinder with a cross-section sufficient for effective defrosting of the movable upstream portion.

[0010] When the air intake is thin, this technology is no longer feasible because the outer cylinder has too large a diameter. An immediate solution to eliminate this drawback is to reduce the outer cylinder's diameter. This implies reducing the inner cylinder's diameter and therefore the cross-sectional area, which then necessitates increasing the number of circulation lines to effectively defrost the moving upstream section, thus increasing mass, cost, and complexity.

[0011] One of the objectives of the present invention is to allow optimal defrosting of an air inlet which is long and has a reduced thickness. PRESENTATION DE L'INVENTION

[0012] The invention relates to an air inlet for an aircraft turbomachine nacelle extending along an axis in which an airflow circulates from upstream to downstream, the air inlet extending annularly around the axis, the air inlet comprising: an upstream movable part and a downstream fixed part, at least one controllable displacement element configured to move the upstream movable part between a retracted position in which the upstream movable part is adjacent to the downstream fixed part and an extended position in which the upstream movable part is separated from the downstream fixed part in order to allow a flow of air through between the upstream movable part and the downstream fixed part and at least one defrosting circuit comprising at least one circulation pipe fluidly connecting the upstream movable part and a hot air source, the defrosting circuit is configured to circulate a flow of hot air in the circulation pipe so as to inject a flow of hot air into the upstream movable part.

[0013] The invention is remarkable in that the circulation pipe comprises at least one upstream non-telescopic duct mounted sliding at the upstream end of the fixed downstream part and at least one downstream telescopic element comprising at least one inner duct mounted in an outer duct and in fluidic connection with the latter, the inner duct being fluidly connected to the upstream non-telescopic duct, the outer duct being fluidly connected to the hot air source.

[0014] Thanks to the invention, the telescopic element is positioned downstream in the fixed section to minimize space constraints. This allows for a reduction in the thickness of the air intake, which is advantageous for a supersonic aircraft. Furthermore, de-icing performance is equivalent whether the element is extended or retracted.

[0015] The internal pipe is configured to move only within the fixed downstream section. In other words, the internal pipe of the telescopic element advantageously does not extend between the moving upstream section and the fixed downstream section in the extended position. The telescopic element is advantageously offset downstream, which limits its footprint at the upstream edge of the fixed downstream section. Thermal expansion of the telescopic element can be more easily mitigated downstream in a larger volume.

[0016] Preferably, at least one end of the downstream telescopic element is equipped with a misalignment compensation device, preferably a piston seal, a bellows, or a guide ball joint. Preferably, each end of the downstream telescopic element is equipped with a misalignment compensation device. Due to the available space downstream, one or more misalignment compensation devices can be installed to correct inaccuracies during deployment / retraction or assembly.

[0017] According to one aspect of the invention, the controllable displacement element is connected directly to the circulation pipe, preferably directly to the upstream non-telescopic section of the circulation pipe. Alternatively, only the circulation pipes are configured to move the upstream section.

[0018] Therefore, advantageously, it is not necessary to include dedicated control mechanisms for movement within the air intake. The circulation duct performs the dual function of movement and de-icing. Furthermore, this prevents icing of movement components that would otherwise be dedicated solely to movement.

[0019] Preferably, the fixed downstream section has a radial thickness of less than 180 mm at its upstream end. Such an air intake is advantageous for improving the aerodynamic performance of a supersonic aircraft.

[0020] According to one aspect, the upstream non-telescopic pipe has a length at least 2 times greater than the telescopic element in the retracted position.

[0021] Preferably, the downstream telescopic element is at least doubly telescopic, preferably triple telescopic, so as to allow a large axial displacement while limiting the size.

[0022] The invention also relates to a nacelle for an aircraft turbomachine, the nacelle comprising at least one air inlet as previously described.

[0023] The invention also relates to a supersonic aircraft comprising at least one turbomachine mounted in a nacelle as previously described.

[0024] The invention also relates to a method for defrosting an air inlet as previously described, comprising a step of circulating a flow of hot air in the circulation duct so as to defrost the upstream movable part in the retracted position and in the extended position. PRESENTATION DES FIGURES

[0025] The invention will be better understood upon reading the following description, given solely by way of example, and referring to the accompanying drawings given by way of non-limiting examples, in which identical references are given to similar objects and on which: [ Fig.1 ] There [ Fig.1 ] is a schematic representation of a nacelle air inlet according to the prior art in the retracted position. Fig.2 ] There [ Fig.2 ] is a schematic representation of a nacelle air inlet according to the prior art in the extended position. Fig.3 ] There [ Fig.3 [ ] is a schematic representation of a nacelle air inlet according to the invention in the retracted position. ] Fig.4 ] There [ Fig.4 [ ] is a schematic representation of a nacelle air inlet according to the invention in the extended position. Fig.5 ] There [ Fig.5 ] is a close-up schematic representation of the telescopic organ of the [ Fig.3 ]. Fig.6 ] There [ Fig.6 ] is a close schematic representation of another embodiment of the air inlet. Fig.7 ] There [ Fig.7 ] is a schematic perspective representation of another form of the air inlet design. Fig.8 ] There [ Fig.8 ] is a schematic representation of an aircraft comprising a turboshaft engine and an air intake assembly.

[0026] It should be noted that the figures explain the invention in detail for implementing the invention, said figures being of course able to serve to better define the invention where appropriate. DESCRIPTION DETAILLEE DE L'INVENTION

[0027] The invention will be presented for an aircraft A comprising at least one turbomachine T as illustrated in the [ Fig.8 ], the turbomachine T being equipped with a nacelle with an air inlet 2 according to the invention.

[0028] The invention finds advantageous application in a supersonic aircraft A, that is, one capable of traveling at a speed greater than that of sound. The [ Fig.8 ] represents aircraft A schematically, the latter being able to have a very different shape.

[0029] With reference to figures 3 et 4 Figure 1 shows a turbomachine T, according to one embodiment of the invention, extending along an axis X and comprising a fan (not shown) mounted to rotate about the axis X in order to accelerate an airflow F from upstream to downstream. Hereafter, the terms upstream and downstream are defined with respect to the axis X oriented from upstream to downstream. Similarly, the terms inside and outside are defined radially with respect to the axis X of the turbomachine T. In this example, the turbomachine T is a turbojet engine.

[0030] The turbomachine T comprises a radially external nacelle which includes an air inlet 2 extending upstream of the fan. This air inlet 2 allows the incoming airflow F to be separated into an internal airflow FINT which is accelerated by the fan and an external airflow FEXT which is guided externally to the nacelle.

[0031] As illustrated in figures 3 et 4 , the air inlet 2 comprises a movable upstream part 2a and a fixed downstream part 2b and at least one controllable displacement element 4 configured to move the movable upstream part 2a between: a PR retracted position ([ Fig.3 ]) in which the movable upstream part 2a is adjacent to the fixed downstream part 2b and an output position PS ([ Fig.4 ]) in which the mobile upstream part 2a is separated from the fixed downstream part 2b in order to allow air to flow through FAT between the mobile upstream part 2a and the fixed downstream part 2b.

[0032] As illustrated in the [ Fig.3 ], in the retracted position PR, the movable upstream part 2a and the fixed downstream part 2b are in contact to form a continuous air inlet 2. Conversely, as illustrated in the [ Fig.4 Representing the outlet position PS, the air inlet 2 is discontinuous, and a through airflow FAT can circulate between the movable upstream part 2a and the fixed downstream part 2b from the outside to the inside, thus improving low-velocity air capture. Preferably, the controllable displacement element 4 is configured to move the movable upstream part 2a upstream.

[0033] In this embodiment, the air inlet 2 has several controllable movement elements 4 distributed around its periphery to allow for robust and precise movement. It goes without saying that the number of controllable movement elements 4 and their positioning could vary.

[0034] In this form of realization, with reference to figures 3 et 4 Each controllable displacement member 4 comprises a movable rod 41 fixed to the movable upstream part 2a of the air inlet 2 which extends longitudinally along an axis X4 which is substantially parallel to the turbomachine axis X. The controllable displacement member 4 comprises an actuator 40 configured to move the movable rod 41 in translation along the axis X4 between the extended position PS and the retracted position PR.

[0035] According to the invention, still with reference to figures 3 et 4 The air inlet 2 includes a defrosting circuit 5 which is configured to defrost the upstream movable part 2a which is in contact with the airflow in the retracted position PR. In the outlet position PS, the defrosting circuit 5 is configured to defrost the upstream movable part 2a, which is in contact with the outside airflow FEXT.

[0036] For this purpose, the defrosting circuit 5 comprises several circulation lines 50 fluidly connecting the upstream mobile section 2a and a hot air source SAC. The defrosting circuit 5 is configured to circulate a flow of hot air FAC through the circulation lines 50 so as to inject a flow of hot air FAC into the upstream mobile section 2a.

[0037] In this example, with reference to the [ Fig.5 The air inlet 2 has a thin profile; that is, the fixed downstream portion 2b has, at its upstream end, a radial thickness E of less than 180 mm. For a supersonic aircraft A, such a thin profile improves aerodynamic performance but is detrimental to de-icing, as explained previously. Although the invention originated for a thin air inlet 2, it is advantageously applicable to an air inlet 2 of any thickness.

[0038] According to the invention, as illustrated in the [ Fig.3 The circulation duct 50 comprises at least one upstream non-telescopic pipe 51 mounted slidingly at the upstream end of the fixed downstream portion 2b and configured to extend between the upstream portion 2a and the downstream portion 2b in the PS outlet position, and at least one downstream telescopic element 52 comprising an inner pipe 521 mounted within an outer pipe 522 and in fluidic connection with the latter, the inner pipe 521 being fluidically connected to the upstream non-telescopic pipe 51, the outer pipe 522 being fluidically connected to the hot air source SAC. Preferably, the upstream non-telescopic pipe 51 has a constant cross-section.

[0039] Advantageously, a downstream offset of the telescopic element 52 reduces the size and mass at the upstream end of the fixed downstream section 2b of the air intake 2. This advantageously reduces both the overhang and the thickness of the air intake 2. This is particularly beneficial for a supersonic aircraft A, which has a long, narrow air intake for aerodynamic reasons. Furthermore, maintenance of the telescopic element 52 is facilitated since the downstream space constraints are reduced.

[0040] The internal pipe 521 is configured to move only within the fixed downstream section 2b. In other words, it does not extend between the upstream section 2a and the downstream section 2b in the PS outlet position. This is particularly advantageous for ensuring optimal guidance of the telescopic element 52.

[0041] In this example, the telescopic member 52 is of the simple type and comprises only an inner pipe 521 and an outer pipe 522. It is understood that the telescopic member 52 could include several pipes nested one inside the other. In particular, the telescopic member 52 could be of the double type and comprise an inner pipe 521 mounted inside a central pipe, which is itself mounted inside an outer pipe 522. Such a telescopic member allows for a significant reduction in overall size. The telescopic member 52 could also be triple telescopic.

[0042] The deployment of the telescopic organ 52 is carried out by means of a controlled actuator (active deployment) or passively following the movement of the upstream movable part 2a of the air inlet 2.

[0043] According to a preferred aspect of the invention, with reference to the [ Fig.5 At least one end of the telescopic member 52 is equipped with a misalignment compensation element 61, 62. In this example, each misalignment compensation element 61, 62 is in the form of a ball joint, but it is understood that it could also be in the form of a piston seal or a bellows. Preferably, each end of the telescopic member 52 is equipped with a misalignment compensation element 61, 62 so as to limit the movement between, on the one hand, the upstream non-telescopic duct 51, which is slidably mounted at the upstream end of the fixed downstream section 2b, and, on the other hand, the hot air source SAC. Due to the downstream positioning, it is possible to provide such compensation elements 61, 62 without increasing the complexity and size at the upstream edge of the fixed section 2b.

[0044] In order to ensure optimal sealing during the deployment / retraction of the telescopic organ 52, it is equipped in a known manner with sealing devices between the different consecutive pipes it comprises.

[0045] In this first form of realization, with reference to figures 3 et 4 The de-icing circuit 5 is independent of the controllable displacement members 4. Preferably, each circulation line 50 is deployed indirectly by the deployment of the controllable displacement members 4. In other words, each circulation line 50 is deployed passively following the movement of the upstream movable part 2a of the air inlet 2 by the controllable displacement members 4.

[0046] In this second form of realization, with reference to figures 6 And 7, at least one circulation pipe 50 is a controllable displacement element 4. Such a feature makes it possible to reduce the bulk significantly, which is advantageous for a fixed downstream part 2b which has a very small thickness.

[0047] The controllable displacement element 4 is used as a means of conducting the hot air flow FAC, and it is not necessary to provide additional technical means that would increase the mass and size. In this embodiment, all the controllable displacement elements 4 are configured to conduct a hot air flow FAC, but it is understood that only some of them could be used for this purpose.

[0048] In this regard, with reference to figures 6 And 7, an actuator 40 is directly connected to the circulation pipe 50 to move the telescopic member 52, that is to say, to move its inner pipe 521 relative to its outer pipe 522. The circulation pipe 50 is thus moved actively.

[0049] According to a preferred design, the actuator 40 is directly connected to the upstream non-telescopic pipe 51 so as to limit the stresses applied to the telescopic member 52 and thus improve its service life. Thus, the upstream non-telescopic pipe 51 performs the same function as the movable rod 41 of the [ Fig.3 As illustrated in the [ Fig.7 ], the upstream non-telescopic pipeline 51 is guided in translation by longitudinally distributed guides 7.

[0050] An example of implementation will be presented with reference to figures 3 et 4 During the flight of the aircraft in conditions requiring the activation of de-icing, the hot air source SAC successively supplies the telescopic member 52 and the non-telescopic duct 51 with a flow of hot air FAC.

[0051] According to the aircraft's initial flight conditions, the air intake 2 is in the retracted position PR as illustrated in the [ Fig.3 In this retracted position PR, the movable upstream part 2a is adjacent to the fixed downstream part 2b of the air inlet 2. The controllable displacement member 4 is in the retracted downstream position and the telescopic member 52 is folded. The circulation duct supplies the movable upstream part 2a of the air inlet 2 as illustrated in [ Fig.3 ].

[0052] When second flight conditions of the aircraft are detected, the controllable displacement element 4 is activated so as to move the movable upstream part 2a in translation along the X4 axis upstream. The air inlet 2 is then in the PS outlet position as illustrated in the [ Fig.4 ].

[0053] In this PS outlet position, the movable upstream part 2a is separated from the fixed downstream part 2b of the air inlet 2, allowing the airflow through FAT to come into contact with the fixed downstream part 2b of the air inlet 2. Following the activation of the controllable displacement element 4, the controllable displacement element 4 is in the upstream PS outlet position. The non-telescopic duct 51 extends between the movable upstream part 2a and the fixed downstream part 2b of the air inlet 2, i.e., in contact with the airflow through FAT to convey a hot air flow FAC.

Claims

1. An air inlet (2) of a nacelle for an aircraft turbomachine (T) extending along an axis (X) in which an air flow (F) circulates from upstream to downstream, the air inlet (2) extending annularly about the axis (X), the air inlet (2) comprising: • a movable upstream part (2a) and a fixed downstream part (2b), • at least one controllable moving member (4) configured to move, during the operation of the turbomachine (T), the movable upstream part (2a) between a retracted position (PR) in which the movable upstream part (2a) is adjacent to the fixed downstream part (2b), and an extended position (PS) in which the movable upstream part (2a) is moved away from the fixed downstream part (2b) in order to allow circulation of a through air flow (FAT) between the movable upstream part (2a) and the fixed downstream part (2b), • at least one de-icing circuit (5) comprising at least one circulation conduit (50) fluidly connecting the moving upstream part (2a) and a source of hot air (SAC), the de-icing circuit (5) is configured to circulate a hot air flow (FAC) in the circulation conduit (50) so as to inject a hot air flow (FAC) into the moving upstream part (2a), which air inlet is characterized in that the circulation conduit (50) comprises: • at least one upstream non-telescopic piping (51) slidably mounted at the upstream end of the fixed downstream part (2b) and • at least one downstream telescopic member (52) comprising at least one internal piping (521) mounted in an external piping (522) and in fluid connection with the same, the internal piping (521) being fluidly connected to the upstream non-telescopic piping (51), the external piping (522) being fluidly connected to the source of hot air (SAC), the internal piping (521) being configured to move only in the fixed downstream part (2b).

2. The air inlet (2) according to claim 1, wherein at least one end of the downstream telescopic member (52) is fitted with a misalignment compensation member (61, 62), preferably a piston seal, a bellows, or a guide ball joint.

3. The air inlet (2) according to one of claims 1 to 2, wherein the controllable moving member (4) is directly connected to the circulation conduit (50), preferably directly to the upstream non-telescopic piping (51) of the circulation conduit (50).

4. The air inlet (2) according to one of claims 1 to 3, wherein the fixed downstream part (2b) has, at its upstream end, a radial thickness (E) of less than 180 mm.

5. The air inlet (2) according to one of claims 1 to 4, wherein the upstream non-telescopic piping (51) has a length at least 2 times higher than the telescopic member (52) in the retracted position.

6. The air inlet (2) according to one of claims 1 to 5, wherein the downstream telescopic member (52) is at least double telescopic, preferably triple telescopic.

7. A nacelle for an aircraft turbomachine (T), the nacelle comprising at least one air inlet (2) according to one of claims 1 to 6.

8. A supersonic aircraft (A) comprising at least one turbomachine (T) mounted in a nacelle according to claim 7.

9. A method for de-icing an air inlet (2) according to one of claims 1 to 6, comprising a step of circulating a hot air flow (FAC) in the circulation conduit (50) in such a way as to de-ice the moving upstream part (2a) in the retracted position (PR) and in the extended position (PS).