Turbomachine comprising an inflatable seal in a discharge channel

Abstract

This aircraft turbomachine (2) comprises at least one compressor (12, 14, 16), a combustion chamber (18), at least one turbine (20, 22), an external flow duct (32), and at least one internal flow duct (30, 36) which is provided with at least one discharge duct (38) whose connection to said internal flow duct (30, 36) is located longitudinally downstream of said compressor (12, 14, 16), and at least one inflatable seal (40) configured to close said discharge duct (38) in an inflated state and to allow air to flow through said discharge duct (38) in a deflated state. Figure for the abbreviation: Fig 1

Description

Title of the invention: Turbomachine comprising an inflatable seal in a discharge channel technical field

[0001] The invention has as its technical domain the operability of turbomachines.

[0002] In particular, the invention relates to an aircraft turbomachine comprising an inflatable seal in a discharge channel of a flow channel of an internal flow. Prior art

[0003] A turbomachine generally comprises a primary gas flow path and a secondary gas flow path. Recently, turbomachines comprising triple flow paths have been designed; such a turbomachine is described, for example, in WO2023 / 198962A1.

[0004] In order to increase the flow of air circulating through a compressor of the turbomachine, it is known to produce an air flow channel, called a discharge channel, which is connected downstream of this compressor and which includes a mechanism capable of closing this discharge channel and allowing air to circulate through this discharge channel.

[0005] It is thus possible to increase the flow of air circulating through this compressor by allowing the air to flow through this discharge channel in order to reduce the air pressure downstream of the compressor.

[0006] A known solution consists of using a set of actuators and links between different actuated parts in order to close this discharge vein or to allow air to circulate through it.

[0007] However, this solution requires a significant amount of space to be implemented, which is incompatible with certain turbomachinery architectures.

[0008] Another solution consists of a variable section nozzle, for example such as described in WO2008 / 045062A1.

[0009] This solution is complex to implement. Description of the invention

[0010] The present invention therefore aims to overcome all or part of the aforementioned drawbacks, and in particular to provide a turbomachine having at least one compression stage whose air flow can be controlled according to the state of a discharge channel of the turbomachine.

[0011] The present invention relates to an aircraft turbomachine comprising at least one compressor, one combustion chamber, at least one turbine, one external flow duct, and at least one internal flow duct in which circulates a flow from at least one compressor and which is equipped with at least one discharge channel, a connection to said internal flow channel of which is located longitudinally downstream of said compressor.

[0012] The turbomachine further includes at least one inflatable seal configured to close said discharge channel in an inflated state and to allow air to flow through said discharge channel in a deflated state.

[0013] The longitudinal direction of the turbomachine corresponds to an axis of rotation of its rotating stages, with radial and tangential directions defining with the longitudinal direction an orthogonal frame specific to the turbomachine.

[0014] The upstream and downstream directions are defined with respect to the main flow direction of the gases along the longitudinal axis of the turbomachine.

[0015] Said discharge vein makes it possible to reduce the air pressure downstream of said compressor when said seal is in the inflated state, and therefore to increase the air flow through said compressor.

[0016] Said inflatable joint is a simple solution to implement and represents a compact solution, allowing its integration into many turbomachine architectures.

[0017] Said compressor may be any rotor stage which is equipped with blades and whose function is to increase the pressure of the air directed towards the combustion chamber.

[0018] Optionally, said inflatable seal is carried by an opening hood of the turbomachine.

[0019] Such a hinged hood may have a plurality of openings, each extending along a limited circumferential sector. Thus, the hinged hood retains sufficient rigidity.

[0020] In a first embodiment, the turbomachine includes a nozzle for separating the flow stream of the external flow, called secondary flow stream, and said flow stream of the internal flow, called primary flow stream, which extends through the combustion chamber.

[0021] Optionally, according to the first embodiment, the turbomachine further comprises at least one other internal flow stream in which flows a stream from said compressor, in particular from an intermediate blower, called third flow stream, and comprises a nozzle for separating the primary flow stream and the third flow stream, the third flow stream being located at least partly radially between the primary flow stream and the secondary flow stream.

[0022] In a second alternative embodiment, the turbomachine comprises at least said internal flow channel, referred to as the third flow channel, and another internal flow channel in which flows a flow from said compressor, in particular the intermediate blower, and which extends through the combustion chamber, called primary flow vein, and includes a nozzle for separating the primary flow vein and the third flow vein, the third flow vein being located at least partly radially between the primary flow vein and the flow vein of the external flow, called secondary flow vein.

[0023] According to the first or second embodiment, the third flow vein remains at a distance from the combustion chamber.

[0024] The use of said inflatable seal arranged in said discharge vein of the The third flow channel is particularly advantageous because the discharge channel is typically designed to discharge 30% of the flow into the third flow channel. The inflatable seal is particularly well-suited to block such a relatively small air discharge rate.

[0025] According to a first design variant of the first or second embodiment, said internal flow vein is radially delimited by an internal wall and by an external wall, said discharge vein extending radially outwards from an opening formed in the external wall of said internal flow vein.

[0026] Said discharge vein extending radially outwards from the opening formed in the outer wall of said internal flow vein allows a direct path for the airflow discharged by said discharge vein

[0027] According to a second design variant of the first or second embodiment, said internal flow vein is radially delimited by an internal wall and by an external wall, said discharge vein extending radially outwards from an opening formed in the internal wall of said internal flow vein.

[0028] Said discharge vein extending radially outwards from the opening formed in the internal wall of said internal flow vein requires few structural modifications to the external cowlings of the turbomachine.

[0029] Optionally, said discharge vein of the third flow vein extending from the opening formed in the internal wall of said internal flow vein remains radially between the primary flow vein and the secondary flow vein.

[0030] According to a particular embodiment, said internal flow channel is provided with at least first and second discharge channels whose respective connections to said internal flow channel are located longitudinally downstream of said compressor, the second discharge channel being located downstream of the first discharge channel, the turbomachine further comprising first and second inflatable joints respectively arranged in the first and second discharge veins.

[0031] Thus, the operability of the turbomachine is further improved.

[0032] Advantageously, said inflatable seal in the inflated state is positioned in said discharge vein at a distance of between 0% and 50% of the length of said discharge vein from its connection to said internal flow vein, in particular between 0% and 25% of the length of said discharge vein, and more particularly between 0% and 10% of the length of said discharge vein.

[0033] Said inflatable joint thus positioned makes it possible to reduce, or even prevent, acoustic resonance phenomena in said discharge vein.

[0034] Advantageously, the turbomachine includes a valve that is configured to draw air from said turbomachine compressor and inject it into said inflatable seal so that it is in the inflated state, and / or a jet pump that is configured to draw air from said inflatable seal so that it is in the deflated state.

[0035] The jet pump can operate with air outside the turbomachine or with air taken from said turbomachine compressor, in particular from the turbomachine high-pressure compressor.

[0036] Optionally, the turbomachine includes a pressure sensor configured to measure a downstream pressure of said compressor, said inflatable seal being controlled in the inflated state and in the deflated state according to a pressure measurement of the pressure sensor.

[0037] Said inflatable seal can be in the inflated state when the air pressure measured by the pressure sensor is above a predetermined pressure threshold and be in the deflated state when the air pressure measured by the pressure sensor is below the predetermined pressure threshold.

[0038] Optionally, the inflatable seal includes a pressure sensor configured to measure a pressure in the inflatable seal and compare it to a pressure in the required inflated or deflated state, in particular to detect a leak.

[0039] Advantageously, said inflatable seal passes from the deflated state to the inflated state by moving downstream of the turbomachine.

[0040] Thus, the airflow circulating in said discharge vein is prevented from acting against the inflatable of said inflatable seal.

[0041] Alternatively, said inflatable seal could pass from the deflated state to the inflated state by moving upstream of the turbomachine.

[0042] Advantageously, the turbomachine includes a propeller equipped with blades that are rotating about a longitudinal axis of the turbomachine.

[0043] Optionally, the propeller is unfaired.

[0044] When the propeller is unshod, the turbomachine lacks a nacelle. In this case, the secondary flow is not radially delimited externally.

[0045] Optionally, the propeller can be shrouded. In this case, the turbomachine can include a nacelle radially delimiting the secondary flow.

[0046] Advantageously, the turbomachine includes a non-rotating stage equipped with a plurality of blades that are non-rotating about the longitudinal axis of the turbomachine, the non-rotating stage being arranged downstream of the propeller.

[0047] Optionally, the plurality of blades of the non-rotating stage has variable pitch or pitch, each blade of the non-rotating stage including in particular a mechanism for adjusting its orientation around a radial axis of the turbomachine.

[0048] Advantageously, the turbomachine includes a shaft, in particular a low-pressure shaft, which is integral with the propeller, said compressor and said turbine.

[0049] In a particular embodiment, the turbomachine further comprises an intermediate fan, in particular shrouded, which constitutes said compressor, the turbomachine further comprising a low pressure compressor, a high pressure compressor, a high pressure turbine, and a low pressure turbine constituting said turbine.

[0050] Advantageously, the low pressure compressor is integral with the low pressure shaft.

[0051] According to a particular design, the intermediate blower is connected to the propeller so that the intermediate blower and the propeller have the same rotational speed.

[0052] According to another particular design, the intermediate blower is connected to the propeller via a reducer so that the intermediate blower and the propeller have a proportional rotational speed.

[0053] It is particularly advantageous to control the compression ratio of the intermediate blower according to this particular design because the range of rotational speeds is very small here and the range of flow rates between idle and full throttle is high.

[0054] Advantageously, the turbomachine includes a shaft which is integral with the high-pressure compressor and the high-pressure turbine.

[0055] The present invention also relates to an aircraft comprising at least one turbomachine as defined above. Brief description of the drawings

[0056] Other objects, features and advantages of the invention will become apparent from the following description, given solely by way of non-limiting example and made with reference to the accompanying drawings in which:

[0057] [Fig. 1] illustrates a turbomachine according to a first example of embodiment of the invention during the inflation of an inflatable seal;

[0058] [Fig.2] illustrates the turbomachine of [Fig.1] during the deflation of the inflatable seal;

[0059] [Fig.3] is a detail view of [Fig.1];

[0060] [Fig.4] illustrates a front frame of the [Fig.1] which is equipped with openings;

[0061] [Fig.5] is a detail view analogous to that of [Fig.3] according to a second example of the implementation of the invention;

[0062] [Fig.6] is a detail view similar to that of [Fig.3] according to a third embodiment of the invention; and

[0063] [Fig.7] illustrates a nozzle of the [Fig.6] which is provided with openings. Detailed description

[0064] Figures 1 and 2 represent an aircraft turbomachine 2 comprising an unfaired propeller 4 which is provided with blades 6 rotating about a longitudinal axis of the turbomachine 2, a non-rotating stage 8 which is provided with a plurality of variable-pitch blades 10 which are non-rotating about the longitudinal axis, a faired intermediate fan 12, a low-pressure compressor 14, a high-pressure compressor 16, a combustion chamber 18, a high-pressure turbine 20, and a low-pressure turbine 22.

[0065] The turbomachine 2 also includes a low-pressure shaft 24 integral with the propeller 4, the intermediate blower 12, the low-pressure compressor 14 and the low-pressure turbine 22, and a high-pressure shaft 26 integral with the high-pressure compressor 16 and the high-pressure turbine 20.

[0066] The turbomachine 2 comprises a first separation nozzle 28 separating a first flow path of the internal airflow 30, referred to as the primary flow path, from a flow path of the external airflow 32, referred to as the secondary flow path. The first separation nozzle 28 is located longitudinally between the propeller 4 and the non-rotating stage 8.

[0067] The turbomachine 2 also includes a second separation nozzle 34 for the primary flow stream 30 and a second internal flow stream 36, referred to as the third flow stream. The second separation nozzle 34 is located longitudinally downstream of the non-rotating stage 8. The third flow stream 36 is located radially between the portion of the primary flow stream 30 extending downstream from the second separation nozzle 34 and the secondary flow stream 32.

[0068] The intermediate blower 12 is located longitudinally between the first separation nozzle 28 and the second separation nozzle 34.

[0069] The primary flow channel 30 delimits a primary airflow which flows from the first separation nozzle 28 through the intermediate blower 12, the low-pressure compressor 14, the high-pressure compressor 16, the chamber of combustion 18, of the high pressure turbine 20 and of the low pressure turbine 22. The primary flow channel 30 is radially delimited by an internal wall 30a and by an external wall 30b.

[0070] The secondary flow vein 32 delimits a secondary air flow which flows from the first separation nozzle 28 radially outside the first separation nozzle 28. The secondary flow vein 32 is not delimited radially outside here.

[0071] The third flow vein 36 delimits a third airflow which flows from the second separation nozzle 34 radially outside the second separation nozzle 34. The third flow vein 36 is delimited radially by an internal wall 36a and by an external wall 36b.

[0072] The turbomachine 2 is therefore a three-flow aircraft engine architecture with three paths for the air that passes through the propeller 4.

[0073] As illustrated more visibly in [Fig.3], a flow channel of an internal flow of the turbomachine 2, and here the third flow channel 36, is provided with a discharge channel 38 which is connected to the flow channel of the internal flow downstream of the intermediate blower 12 which has in particular the function of increasing the pressure of the air directed towards the combustion chamber 18.

[0074] The discharge vein 38 is here connected on one side to the third flow vein 36, and opens on the other side onto a radially external surface of the turbomachine 2, the discharge vein 38 extending radially outwards from an opening formed in the external wall 36b of the third flow vein 36 remaining radially outside the first flow vein 30, in particular remaining radially between the primary flow vein 30 and the secondary flow vein 32 and opening into the secondary flow vein 32.

[0075] The discharge vein 38 here has a sigmoid shape and, as such, comprises a first curved portion along a first direction and a second curved portion along a second direction opposite to the first direction. A radially inner wall of the first curved portion is concave, and a radially inner wall of the second curved portion is convex. The discharge vein 38 thus has an inflection point between its first and second curved portions. This particular shape of the discharge vein 38 allows for better discharge of an airflow through the discharge vein 38.

[0076] The turbomachine 2 further includes an inflatable seal 40 suitable, in an inflated state, for closing the discharge channel 38 and, in a deflated state, for allowing air to circulate through the discharge channel 38.

[0077] The inflatable seal 40 in the inflated state is positioned in the upstream half of the discharge vein 38 of the third flow, that is to say at a distance between 0% and 50% of the length of the discharge vein 38 from its connection to the third flow vein 36, in particular between 0% and 25% of the length of the discharge vein 38, and more particularly between 0% and 10% of the length of the discharge vein 38.

[0078] The turbomachine 2 includes an opening hood frame 42 located upstream of the discharge vein 38 of the third flow vein 36. The inflatable seal 40 is connected to the opening hood frame 42 so as to pass from the deflated state to the inflated state by deploying downstream of the turbomachine 2.

[0079] The turbomachine 2 also includes a valve 44, for example a three-way valve, which is suitable for taking air from a compression stage of the turbomachine 2, for example from the low-pressure compressor 14, and injecting it into the inflatable seal 40 so that it changes from the deflated state to the inflated state, as well as a jet pump 46 operating with air outside the turbomachine 2 and air taken from the high-pressure compressor 16 and which is suitable for taking air from the inflatable seal 40 so that it changes from the inflated state to the deflated state.

[0080] Thus, the turbomachine 2 includes a pipe extending from the low-pressure compressor 14 to the valve 44, a pipe extending from the valve 44 to the inflatable seal 40, and a pipe extending from the valve 44 to the outside of the turbomachine 2. The turbomachine 2 further includes a pipe extending from the high-pressure compressor 16 to the jet pump 46, a pipe extending from the jet pump 46 to the inflatable seal 40, and a pipe extending from the jet pump 46 to the outside of the turbomachine 2.

[0081] The turbomachine 2 also includes a pressure sensor 48 suitable for measuring a downstream pressure of the intermediate blower 12, and here arranged in the primary flow channel 30 longitudinally between the intermediate blower 12 and the second separation nozzle 34. The inflatable seal 40 is controlled in the inflated and deflated state according to the pressure measurements of the pressure sensor 48.

[0082] The turbomachine 2 further includes a sensor 49 arranged in the inflatable seal 40 which is capable of measuring a pressure in the inflatable seal 44 and comparing it to a pressure in the inflated or deflated state required, in particular to detect a leak.

[0083] Fig. 4 represents the front frame of the turbomachine 2 which is equipped with the opening hood 42. The opening hood 42 has a plurality of openings 50 each extending along a limited circumferential sector, the airflow circulating through the discharge vein 38 of the third flow vein 36 being discharged through the openings 50 of the opening hood 42.

[0084] Figure 5 represents a variant of the embodiment illustrated in Figures 1 to 4 in which the flow path of an internal flow of the turbomachine 2, here the third flow path 36, is provided with a first discharge path 38a and a second discharge path 38b, each connected to the third flow path 36 downstream of the intermediate fan 12, the second discharge path 38b being located longitudinally downstream of the first discharge path 38a. Of course, in an alternative to this variant of the embodiment, the turbomachine 2 could be provided with only one of the first and second discharge paths 38a, 38b, particularly depending on the longitudinal position at which it is necessary to discharge the flow path 36.

[0085] The turbomachine 2 here comprises a first inflatable seal 40a arranged in the first discharge channel 38a and a second inflatable seal 40b arranged in the second discharge channel 38b.

[0086] The embodiment illustrated in [Fig. 6] differs from the first embodiment illustrated in Figures 1 to 4 in that the discharge channel 38 of the third flow channel 36 extends radially inward from an opening formed in the inner wall 36a of the third flow channel 36, remaining radially within the third flow channel 36, in particular remaining radially between the primary flow channel 30 and the third flow channel 36. The discharge channel 38 of the third flow channel 36 is here radially delimited internally by an internal firewall of the turbomachine 2. In the embodiment illustrated in [Fig. 6], the discharge channel 38 of the third flow channel 36 opens downstream in an annular fashion. In particular, one discharge outlet of the discharge channel 38 is annular.The discharge outlet of the discharge channel 38 is delimited longitudinally by upstream fairings 51a and downstream fairings 51b of the turbomachine 2, the downstream fairing 51b being located radially inside a fictitious extension of the upstream fairing 51a. In other words, the discharge outlet of the discharge channel 38 is here slightly raised.

[0087] Fig. 7 illustrates a nozzle 52 of the turbomachine 2 which is provided with openings 54 each extending along a limited circumferential sector, the airflow circulating through the discharge vein 38 of the third flow vein 36 being discharged through the openings 54 of the nozzle 52.

[0088] The openings 54 of the nozzle 52 differ from the openings 50 of the hinged cowling 42 shown in [Fig. 4] in that the nozzle 52 comprises a plurality of flush walls, each flush wall extending from an edge of an opening 54 of the nozzle 52 so as to extend a surface of the discharge stream 38 of the third flow stream 36. In other words, upstream and downstream fairings of the turbomachine 2 which longitudinally delimit the openings 54 are in the extending from one another. Thus, aerodynamic losses are limited at the outlet of discharge channel 38.

[0089] In the examples shown, the turbomachine is a three-flow turbomachine. Alternatively, the turbomachine could include primary and secondary flow channels 30, 32 and not include a third flow channel 36. In this alternative, the discharge channel 38 could extend from the primary flow channel 30.

Claims

Demands

1. A turbomachine (2) for an aircraft comprising at least one compressor (12, 14, 16), a combustion chamber (18), at least one turbine (20, 22), an external flow channel (32), and at least one internal flow channel (30, 36) through which flows a flow from at least one compressor (12, 14, 16) and which is provided with at least one discharge channel (38, 38a, 38b) a connection to said internal flow channel (30, 36) being located longitudinally downstream of said compressor (12, 14, 16), characterized in that it further comprises at least one inflatable seal (40, 40a, 40b) configured to close said discharge channel (38, 38a, 38b) in an inflated state and to permit the flow of air through of said discharge vein (38, 38a, 38b) in a deflated state.

2. Turbomachine (2) according to claim 1, comprising a separation nozzle (28) of the external flow stream (32), referred to as secondary flow stream (32), and of said internal flow stream (30), referred to as primary flow stream (30), which extends through the combustion chamber (18).

3. Turbomachine (2) according to claim 1, comprising at least said internal flow channel (36), referred to as third flow channel (36), and another internal flow channel in which flows a flow from said compressor (12, 14, 16), and which extends through the combustion chamber (18), referred to as primary flow channel (30), and comprising a separating nozzle (34) of the primary flow channel (30) and the third flow channel (36), the third flow channel (36) being located at least partly radially between the primary flow channel (30) and the external flow channel (32), referred to as secondary flow channel (32).

4. Turbomachine (2) according to any one of claims 1 to 3, wherein said internal flow channel (30, 36) is radially delimited by an internal wall (30a, 36a) and by an external wall (30b, 36b), said discharge channel (38, 38a, 38b) extending radially outwards from an opening formed in the external wall (30b, 36b) of said internal flow channel (30, 36).

5. Turbomachine (2) according to any one of claims 1 to 3, wherein said internal flow channel (30, 36) is radially delimited by an internal wall (30a, 36a) and by an external wall (30b, 36b), said discharge channel (38, 38a, 38b) extending radially inwards from an opening formed in the internal wall (30a, 36a) of said internal flow channel (30, 36).

6. Turbomachine (2) according to claim 5 dependent on claim 3, wherein said discharge vein (38, 38a, 38b) of the third flow vein (36) extending from the opening formed in the inner wall (30a, 36a) of said internal flow vein (30, 36) remains radially between the primary flow vein (30) and the secondary flow vein (32).

7. Turbomachine (2) according to any one of claims 1 to 6, wherein said internal flow channel (30, 36) is provided with at least first and second discharge channels (38a, 38b) whose respective connections to said internal flow channel (30, 36) are located longitudinally downstream of said compressor (12, 14, 16), the second discharge channel (38b) being located downstream of the first discharge channel (38a), the turbomachine (2) further comprising first and second inflatable seals (40a, 40b) respectively arranged in the first and second discharge channels (38a, 38b).

8. Turbomachine (2) according to any one of claims 1 to 7, wherein said inflatable seal (40, 40a, 40b) in the inflated state is positioned in said discharge channel (38, 38a, 38b) at a distance between 0% and 50% of the length of said discharge channel (38, 38a, 38b) from its connection to said internal flow channel (30, 36), in particular between 0% and 25% of the length of said discharge channel (38, 38a, 38b), and more particularly between 0% and 10% of the length of said discharge channel (38, 38a, 38b).

9. Turbomachine (2) according to any one of claims 1 to 8, comprising a valve (44) configured to draw air from said compressor (14, 16) of the turbomachine (2) and inject it into said inflatable seal (40, 40a, 40b) so that it is in the inflated state, and / or a jet pump (46) configured to draw from

10. the air of said inflatable joint (40, 40a, 40b) so that it is in the deflated state (2). Turbomachine (2) according to any one of claims 1 to 9, comprising a pressure sensor (48) configured to measure a downstream pressure of said compressor (12, 14, 16), said inflatable seal (40, 40a, 40b) being controlled in the inflated and deflated states as a function of a pressure measurement of the pressure sensor (48).

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