EP4259916A1

EP4259916A1 - Turbine engine for an aircraft

Info

Publication number: EP4259916A1
Application number: EP21848164.6A
Authority: EP
Inventors: Vincent Marie Jacques Rémi De Carné-Carnavalet
Original assignee: Safran Aircraft Engines SAS
Current assignee: Safran Aircraft Engines SAS
Priority date: 2020-12-08
Filing date: 2021-12-02
Publication date: 2023-10-18
Also published as: CN116635617A; WO2022123151A1; FR3117172B1; FR3117172A1; US20240018905A1

Abstract

The invention relates to a turbine engine (1) extending along an axis (X), comprising a flow path (2) of a primary flow (F1) comprising a compressor, a combustion chamber and a turbine, an outflow region (3) of a secondary flow (F2), surrounding the primary path (2), a blower (6) or a propeller located upstream of the primary path (2) and the outflow region (3) of the secondary flow (F2), at least one arm (7) extending radially through the primary path (2), at least one fluid circulation pipe extending inside the arm (7), characterised in that the arm (7) comprises an inlet for air from the primary path so as to cool the fluid circulating in the pipe.

Description

DESCRIPTION

TITLE: Turbomachine for an aircraft

Technical field of the invention

The invention relates to a turbomachine, such as for example a turbojet or an aircraft turboprop, in particular an airplane.

State of the prior art

A turbomachine conventionally comprises a flow path for a primary flow, or primary path, comprising a compressor, a combustion chamber and a turbine, a flow zone for a secondary flow, surrounding the primary path, and a fan or a helix located upstream of the primary vein and the secondary flow flow zone.

The secondary flow flow zone can be delimited radially on the outside by a shroud, so as to delimit a circulation vein of a secondary flow, or secondary vein. Alternatively, the secondary stream flow area may also be unstreamlined.

The turbomachine further comprises a fan or a propeller, located upstream of the primary stream and the flow zone of a secondary flow. An element of the turbomachine surrounds the primary stream and is located downstream of the fan and makes it possible to separate the primary flow from the secondary flow. This element is for example formed by part of an intermediate casing.

Profiled arms generally extend radially through the primary vein, so as to allow the passage of transmission or service elements through the arms.

The new types of turbomachine architecture have elements such as power transmission boxes or reduction gears, whose gears have significant lubrication requirements. In addition, some systems also have fan blade timing change systems which further add to the lubrication demand. These increased needs are obviously in addition to the conventional lubrication needs of the turbomachine. The new architectures thus require a substantial oil requirement and, at the same time, a higher cooling requirement for this oil than conventional architectures.

The reduction gear and the timing change mechanisms are generally located in the radially internal part of the turbomachine and are supplied with lubricating oil by pipelines. These then pass conventionally through the primary flow, inside the aforementioned arms, in order to ensure the connection between these oil-consuming systems and the systems ensuring the circulation as well as the cooling of the oil.

Today there is a need to improve the cooling of the oil circulating through these pipes.

Indeed, the much higher lubrication needs of new turbomachine architectures imply a strong increase in the need for heat exchange in order to cool the lubricant. The heat exchange systems used in conventional turbomachine architectures are not sufficient or lead to prohibitive performance losses in the operation of the turbomachine.

Presentation of the invention

The invention aims to meet this need, in a simple, reliable and inexpensive manner.

To this end, the invention relates to a turbomachine extending along an axis, comprising a flow path for a primary flow comprising a compressor, a combustion chamber and a turbine, a flow zone for a secondary flow , surrounding the primary vein, a blower or a propeller located upstream of the primary vein and of the flow zone of the secondary flow, at least one arm extending radially through the primary vein, at least one circulation pipe of fluid extending inside the arm, characterized in that the arm comprises an air inlet coming from the primary stream so as to cool the fluid circulating in the said pipe.

The terms axial, radial and circumferential are defined with respect to the axis of the turbomachine. Furthermore, the terms upstream and downstream are defined with respect to the direction of circulation of the gases within the turbomachine.

The invention proposes to take advantage of the passage of the pipe through the arm in order to carry out all or part of the heat exchanges necessary for cooling the fluid. For this, part of the air passing through the primary vein is taken through the air inlet of the arm.

The pipe thus forms a heat exchanger, in its part passing through the arm. The pipe can then, in this part at least, have any suitable shape in order to ensure the heat exchange function.

The air inlet is positioned in such a way as to capture the dynamic pressure coming from the fan or the propeller and entering the primary vein.

The fluid can be oil or another heat transfer fluid. The arm can be located upstream of the compressor. The turbomachine may include a low pressure compressor and a high pressure compressor. The arm can then be located before the low pressure compressor.

In this way, the air entering the arm has a relatively low temperature, which makes it possible to maximize the cooling of the fluid circulating in the pipe.

The arm may comprise two lateral surfaces defining upstream at least one leading edge and downstream at least one trailing edge, the air inlet being located at the level of the leading edge and/or at the at least one of the side surfaces of the arm.

The air inlet can be formed by an opening.

The air inlet can be located at the leading edge of the arm. The air inlet can then be called a front scoop.

The air inlet may extend circumferentially from the corresponding side surface of the arm.

Thus, the air inlet can be located at the level of at least one of the side surfaces of the arm. Such an air inlet can also be called a side scoop. In this case, the air inlet can be a simple opening or extend circumferentially from the corresponding side surface of the arm, for example in the form of a cap, so as to allow the flow rate to be increased. captured by the air inlet (so-called dynamic scoop).

Alternatively, the air inlet can be formed by a simple opening extending into the area bounded by the arm.

The pipe can be equipped with a heat exchanger housed in the arm. Said exchanger may comprise fins making it possible to increase the exchange surfaces with the air flowing in the arm.

As a variant, the heat exchange between the air and the fluid circulating in the pipe can be carried out only through the wall, for example cylindrical, of the said pipe. The arm may include an air outlet.

The air outlet can be located at the radially outer end of the arm and can open out into an element of the turbomachine located radially between the primary stream and the secondary flow flow zone.

This element may be part of an intermediate casing of a turbomachine, in particular in the case where the turbomachine is a turbofan engine.

Said element may comprise at least one air flow circulation duct connecting said outlet of the arm to an opening of said element opening out into the secondary flow flow zone.

Said opening can be equipped with an ejection grid. Said ejection grille may comprise fins for redirecting the flow of air crossing it, so as to align the flow of air issued the grid with the direction of the secondary flow. Such a grid then makes it possible not to penalize too strongly the flow of the secondary flow.

Said element may comprise a first duct connecting the outlet of the arm to a second duct connecting the primary vein to the secondary flow flow zone.

The second conduit can connect a shutter or a controlled valve located at the level of a radially outer wall of the primary stream to the flow zone of the secondary flow. Such a valve (also called Variable Bleed Vane or V.B.V.) makes it possible to adjust the flow of air circulating through the primary duct, for example in order to adjust the idle speed. Such a valve can also have the function of extracting debris or foreign bodies introduced into the primary stream, so as to protect the elements located downstream. Such foreign bodies can be hail, rain or dust for example. It should be noted that, in the case of hail extraction in particular, the risk of accumulation of ice at the level of the outlet of the second duct is limited by the contribution of calories from the hot air coming from the arm.

The air outlet can be formed in the arm and can open into the primary vein.

The air outlet can then be located in a downstream zone of the arm, for example at the trailing edge.

The arm may include means for adjusting the section of the air inlet and/or the air outlet. These adjustment means may comprise at least one movable member, the position of which can be controlled and makes it possible to adjust the section of the air inlet, possibly dynamically by means of a regulation.

The turbomachine may comprise a stator comprising blades located axially, in part or in whole, facing the arm. The blades can be located on either side of the arm. The blades can be interposed circumferentially between two arms.

The turbomachine may include a stator comprising blades located axially upstream of the arm. One of the stator blades may be located circumferentially opposite the arm.

The axial dimension of each stator blade may be less than the axial dimension of the arm. The circumferential dimension of each stator blade may be less than the circumferential dimension of the arm. The downstream end of each blade can be located upstream from the downstream end of the arm.

The arm can be located upstream of a low pressure compressor.

Such a characteristic is in particular applicable to the case where the turbine engine comprises a reduction gear between the rotor of the fan and a shaft connecting the low pressure turbine and the low pressure compressor. Indeed, such a reducer has a large mass and is generally located axially upstream of the low pressure compressor. The aforementioned arm is moreover generally connected to a fixed part of the aircraft, so as to provide an anchorage or a fastening of the turbine engine on the aircraft. The fact of placing the arm upstream of the low pressure compressor thus makes it possible to limit the lever arm in the anchoring zone and the mass formed by the reducer.

Brief description of figures

[Fig. 1] is a half-view in schematic axial section of a turbomachine according to the invention,

[Fig. 2] is a schematic axial sectional view of part of the turbomachine,

[Fig. 3] is a schematic view along a section plane perpendicular to the radial direction of extension of the arm, illustrating a first embodiment of the invention, [Fig. 4] is a view corresponding to FIG. 3, illustrating a second embodiment of the invention,

[Fig. 5] is a view corresponding to FIG. 3, illustrating a third embodiment of the invention,

[Fig. 6] is a view corresponding to FIG. 2, illustrating a fourth embodiment of the invention,

[Fig. 7] is a view corresponding to FIG. 2, illustrating a fifth embodiment of the invention,

[Fig. 8] is a view corresponding to FIG. 2, schematically illustrating a sixth embodiment of the invention,

[Fig. 9] is a detail view of part of the arm, illustrating a seventh embodiment of the invention,

[Fig. 10] is a view corresponding to Figure 3, illustrating the positioning of the blades of a stator, said blades being located circumferentially on either side of the arm, in accordance with an eighth embodiment of the invention,

[Fig. 11] is a view corresponding to FIG. 10, illustrating another embodiment in which the arm is located downstream of the blades of the reducer,

[Fig. 12] is a perspective view of a turbine engine with an unducted fan of the propeller type.

Detailed description of the invention

Figures 1 and 2 schematically illustrate a turbomachine 1, in particular a turbofan aircraft engine, according to one embodiment of the invention. The turbomachine 1 extends along an axis X. The turbomachine 1 comprises a stream 2 for the flow of a primary stream, or primary stream 2, comprising a compressor, a combustion chamber and a turbine, and a stream 3 for the flow of a secondary stream, or secondary stream 3 , surrounding the primary vein 2.

The upstream part of the primary stream 2 is separated from the secondary stream 3 by a part 4 of a so-called intermediate casing, delimiting in particular a splitter nozzle 5.

The turbomachine 1 further comprises a fan 6 located upstream of the primary stream 2 and of the secondary stream 3 being, like the latter, streamlined by a 3N nacelle.

The airflow passing through the fan 6 is split into two, namely a primary flow F1 entering the primary stream 2 and a secondary flow F2 entering the secondary stream 3.

Profiled arms 7 extend radially through the primary stream 2, in particular upstream of the compressor, so as to allow transmission or service elements to pass through the arms 7. These arms are in the example represented in the entry zone of the primary stream, axially close to the splitter nozzle 5. Each arm 7 comprises two lateral surfaces 8 connected upstream by a leading edge 9 and connected downstream by a trailing edge 10.

The turbomachine 1 may further comprise a power transmission box or a lubricated reducer 11.

The turbomachine 1 may further comprise a device 12 for changing the timing of the fan blades 6, also lubricated.

The power transmission box or the reducer 11, and the timing change mechanisms 12 are located in the radially internal part of the turbomachine 1 and are supplied with lubricating oil by pipes 13. These pipes 13 cross the primary stream 2 at the through at least one of the arms 7, in order to ensure the connection between these oil-consuming systems 11, 12 and the systems ensuring the circulation as well as the cooling of the oil, located radially outside the primary vein 2.

FIG. 3 illustrates the section of an arm 7 along a plane perpendicular to the radial axis of extension of the arm 7. The arm 7 comprises an air inlet 14 formed by a slot extending over at least part of the leading edge 9 of arm 7. Arm 7 further comprises an air outlet 15 formed by a slot extending over at least part of trailing edge 10 of arm 7.

In operation, cold air from the upstream end of the primary stream 2 enters the internal volume 16 of the arm 7, in which the pipes 13 are housed, via the inlet 14, crosses said internal volume 16 coming cool the pipes 13, and is extracted from said internal volume 16 through the outlet 15 to emerge again in the primary stream 2. FIG. 4 illustrates another embodiment in which the arm 7 comprises an air inlet 14 formed by an opening at the level of one of the side surfaces 8. The air outlet 15 of the arm 7 is located at the level of the radially outer end of the arm 7 so that, in operation, air enters the internal volume 16 through the inlet 14, circulates in the internal volume 16 of the arm 7 so as to cool the pipes 13 and escapes into the internal volume 17 of part 4 of the intermediate casing, as illustrated in FIG. 6. Also in this figure, the pipes 13 can be equipped with one or more heat exchangers 18, for example provided with fins allowing to favor the heat exchange surfaces.

Figure 5 illustrates another embodiment in which the arm 7 comprises two air inlets 14, formed by openings located respectively at the level of each of the side surfaces 8 of the arm 7.

Each opening 14 can extend circumferentially from the corresponding lateral surface 18 of the arm 7, for example in the form of a cap, so as to allow the flow captured by the opening 14 to be increased. Such an opening 14 forms a so-called dynamic scoop. As before, the air outlet 15 of the arm 7 is located at the radially outer end of the arm 7 so that, in operation, air enters the internal volume 16 through the inlet 14, circulates in the internal volume 16 of the arm 7 so as to cool the pipes 13 and escapes into the volume 17 of the part 4 of the intermediate casing.

Figure 7 illustrates another embodiment, in which the outer wall 19 of part 4 of the intermediate casing includes an ejection grille 20 communicating with the secondary stream 3.

The ejection grille 20 may include fins 21 for redirecting the airflow passing through it, so as to align the airflow from the grille 20 with the direction of the secondary flow F2. Such a grid 20 then makes it possible not to penalize too strongly the flow of the secondary flow F2.

In operation, the air from the arm 7 emerges in the internal volume 17 of the part 4 of the intermediate casing then is discharged into the secondary stream 3, through the ejection grille 20.

According to an embodiment not shown, a duct can connect the outlet of the arm 7, at the radially inner end of the arm 7, and the opening 23 of the wall 19 presenting the ejection grille 20.

FIG. 8 schematically illustrates another embodiment, in which said part 4 comprises a first duct 24 and a second duct 25. To make this figure more readable, the proposals of the ducts with respect to their environment are not respected by compared to the proportions if these conduits would actually be implemented in a real turbomachine. The first duct 24 connects the outlet 15 of the arm 7 and a middle zone of the second duct 25. The second duct 25 connects a flap or a controlled valve 26 located at the level of a radially outer wall 27 of the primary stream 2, one hand, and the opening 23 equipped with the grid 20, on the other hand.

Such a valve 26 (also called Variable Bleed Vane or V.B.V.) can in particular make it possible to adjust the flow of air circulating through the primary stream 2, for example so as to adjust the idle speed. Such a valve 26 can also have the function of extracting debris or foreign bodies introduced into the primary stream 2, so as to protect the elements of the turbomachine 1 located downstream, in particular the high pressure compressor (not shown) knowing that a low pressure compressor (not shown) is axially downstream of the arms and upstream of the valve.

FIG. 9 illustrates another embodiment in which the arm 7 comprises means for adjusting the section of the air inlet 14. These adjustment means comprise at least one movable member 28 whose position can be controlled and makes it possible to adjust the section of the air inlet 14, optionally dynamically by means of a regulation. Here two opposite moving parts 28 are used, the air inlet 14 being delimited between the opposite ends of the moving parts 28.

Furthermore, as illustrated in FIG. 10, the turbine engine 1 may comprise a rectifier comprising blades 29 extending radially and located axially, in part or in whole, opposite the arm 7 and located circumferentially on either side of the arms 7.

FIG. 11 illustrates an embodiment in which the arm is located downstream of the blades of the stator, the arm being moreover located circumferentially facing one of the blades of the stator.

The axial dimension of each stator blade 29 is less than the axial dimension of arm 7. The circumferential dimension of each stator blade 29 is less than the circumferential dimension of arm 7.

The downstream end 30 of each blade 29 is located upstream of the trailing edge 10 of the arm 7. As illustrated in FIG. 12, the invention is also applicable to a turbomachine 1 with an unducted fan 6 of the propeller type, comprising a open secondary flux zone in which is located a rectifier 7 belonging to a stator. Such a structure is similar to the case of FIG. 1, the turbomachine 1 not comprising in this case any 3N nacelle. Such a turbomachine 1 is also known by the acronym “USF” (for Unducted Single Fan).

Claims

1 . Turbomachine (1) extending along an axis (X), comprising a stream (2) for the flow of a primary flow (F1) comprising a compressor, a combustion chamber and a turbine, a zone (3) of flow of a secondary stream (F2), surrounding the primary stream (2), a blower (6) or a propeller located upstream of the primary stream (2) and the secondary stream flow zone (3) ( F2), at least one arm (7) extending radially through the primary stream (2), at least one fluid circulation pipe (13) extending inside the arm (7), characterized in that the arm (7) comprises an air inlet from the primary stream so as to cool the fluid circulating in the said pipe, the arm (7) comprising an air outlet (15), the air outlet ( 15) being located at the radially outer end of the arm (7) and opening into an element (4) of the turbomachine (1) located radially between the primary stream (2) and the secondary flow zone (3), said element (4) comprising a first conduit (24) connecting the outlet of the arm (7) to a second conduit (25) connecting the primary vein (2) to the zone (3) of flow of the secondary flow (F2).

2. Turbomachine (1) according to the preceding claim, characterized in that the arm (7) comprises two side surfaces (8) defining upstream at least one leading edge (9) and downstream at least one trailing edge (10), the air inlet (14) being located at the level of the leading edge (9) and/or at the level of at least one of the side surfaces (8) of the arm (7).

3. Turbomachine (1) according to the preceding claim, characterized in that the air inlet (14) extends circumferentially from the side surface (8) corresponding to the arm (7).

4. Turbomachine (1) according to one of the preceding claims, characterized in that said element (4) comprises at least one duct (24, 25) for circulating the air flow connecting said outlet of the arm (7) to a opening (23) of said element (4) opening into the flow zone (3) of the secondary flow (F2).

5. Turbomachine (1) according to one of the preceding claims, characterized in that the arm (7) comprises means (28) for adjusting the section of the air inlet (14) and / or the air outlet (15).

6. Turbomachine (1) according to one of the preceding claims, characterized in that the arm (7) is located upstream of a low pressure compressor.

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