Flow deflector having channels with double ejection angles

Abstract

The invention relates to a flow deflector (21) for a compressor of a ducted-fan turbine engine (1) having a longitudinal axis, the flow deflector comprising a wall (25) provided with a plurality of ejection channels (29) capable of discharging a discharge air flow into a flow path of the turbine engine in which an air flow circulates, the ejection channels, having an axis (C), being arranged in multiple rows and being configured so as to eject the discharge air flow in the flow direction of the air flow, the axes (C) each being oriented in a first direction forming a first angle (α) with respect to an axis (B) parallel to an axis of revolution of the discharge deflector. According to the invention, the projection of the axes of the ejection channels (29) of each row in a projection plane (PP) perpendicular to the median plane (PM) forms a second angle (β) with a straight line parallel to the median plane.

Description

Description TITLE: FLOW DEFLECTOR WITH DUAL EJECTION ANGLE CHANNELS. Technical field of the invention

[0001] The present invention relates to the field of turbomachines, in particular dual-flow turbomachines for aircraft. It relates in particular to a flow deflector making it possible to discharge a portion of an air flow passing from a compressor into a vein of the turbomachine. It also relates to a turbomachine comprising such a flow deflector. Technological background

[0002] It is known to equip dual-flow turbomachines with one or more air discharge systems from a compressor assembly. These systems are known under the English designation "Handling Bleed Valve" (abbreviated HBV) or "Transient Bleed Valve" (abbreviated TBV) allowing to take a portion of the primary flow from the high-pressure compressor or "Variable Bleed Valve" (abbreviated VBV) allowing to take a portion of the primary flow from the low-pressure compressor. The air flows taken are ejected into the secondary flow or downstream of the primary flow. The purpose of this discharge is, on the one hand, to stabilize the operation of the low-pressure compressor and / or the high-pressure compressor and, on the other hand, to limit certain phenomena that can hinder their operation such as surge, rotating separation or flutter.

[0003] The HBV type discharge system comprises a plurality of openings opening into the secondary vein where the secondary flow circulates. The jet of air flow ejected by the discharge system into the secondary vein can impact the parts around the openings such as the inner wall partly delimiting the secondary vein known by the acronym IFD for (Inner Fan Duct) or the outer wall partly delimiting the secondary vein known by the sign OFD for (Outer Fan Duct), and possibly other parts in the wake of the air flow. The openings can be oriented in the direction of the secondary flow or in a direction transverse to the air flow in order, on the one hand, to increase the incorporation of the discharged primary flow into the secondary flow, and on the other hand to limit the thermal stresses on the neighboring structures and / or components which are not configured for withstand high temperatures. Such an example of a discharge system is described in documents FR-A1-3057026, FR-A1-3057028 and US-B2-6588195.

[0004] However, with this known discharge system, there remains a risk that certain parts around the ejection area of ​​the air taken from the compressor could still be significantly impacted, particularly with regard to the OFD and the thrust reverser.

[0005] There is a need to address some or all of the above drawbacks. Summary of the invention

[0006] The objective of the present invention is to provide an air flow deflector allowing better distribution of the air flow at its outlet while avoiding thermal constraints and while being economical and simple to produce.

[0007] We achieve this objective in accordance with the invention by means of a flow deflector of a discharge system of a turbomachine compressor with a longitudinal axis, the flow deflector comprising a wall provided with a plurality of ejection channels capable of discharging a discharge air flow from the compressor into a vein of the turbomachine in which an air flow circulates in a flow direction, the axis ejection channels being arranged in several rows in alignment directions substantially parallel to a median plane of the flow deflector which is substantially parallel to the flow direction and being configured so as to eject the discharge air flow in the flow direction, the axes each being oriented in a first direction forming a first angle relative to an axis parallel to an axis of revolution of the flow deflector,the projection of the axes of the ejection channels of each row in a projection plane perpendicular to the median plane forming a second angle with a straight line parallel to the median plane.,

[0008] Thus, this solution makes it possible to achieve the aforementioned objective. In particular, the orientation of each ejection channel according to two angles, and in particular the second angle (axial and tangential orientation), makes it possible to orient the air flow jet at the outlet of the deflector so as to quickly homogenize the mixture and to reduce the thermal impact on the thermally sensitive parts without impacting the acoustics of the deflector. The arrangement of the second angle makes it possible on the one hand to reduce the temperature of the jet at the outlet of the deflector which makes it possible to further protect the walls such as the radially internal and external walls delimiting the vein of the turbomachine as well as the surrounding parts such as a thrust reverser which can be carried by one of the walls of the vein, and on the other hand the expansion of the discharge air flow.

[0009] The deflector also includes one or more of the following features, taken alone or in combination: - the ejection channels of each row have a circular cross-section. - the values ​​of the second angles are symmetrical with respect to the median plane. - the second angle increases from the median plane towards the edge of the deflector in a direction perpendicular to the median plane. - the variation of the second angle is progressive. - the second angle is constant in the same row on either side of the median plane. - the ejection channels are arranged so as to form curved lines parallel to each other, transverse to the median plane and symmetrical to the median plane. - the first angles of each row are constant. - each first angle of the same row varies by decreasing between an upstream edge and a downstream edge of the wall according to the direction of flow of the air flow.

[0010] The invention also relates to a turbomachine comprising at least one deflector having any of the preceding characteristics. The second angle considerably improves the protection of the structure of the turbomachine at the radially outer wall (OFD) when the deflector is mounted in the turbomachine.

[0011] The invention further relates to an aircraft comprising a turbomachine as mentioned above. Brief description of the figures

[0012] The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly on reading the detailed explanatory description which follows, of embodiments of the invention given as purely illustrative and non-limiting examples, with reference to the appended schematic drawings in which: - Figure 1 represents in axial and partial section, an example of a turbomachine to which the invention applies; - Figure 2 is a schematic and axial sectional view of a vein in which an example of a discharge system according to the invention is positioned; - Figure 3 illustrates a cross-sectional view of an example of a discharge system according to the invention; - Figure 4 is a top view of the discharge system according to Figure 3. Detailed description of the invention

[0013] Figure 1 schematically shows a turbomachine for an aircraft according to the invention. The turbomachine 1 illustrated is a double-flow, double-spool turbojet engine which extends along a longitudinal axis X.

[0014] The turbomachine 1 generally comprises a gas generator 2. The latter generally comprises, from upstream to downstream, a low-pressure compressor 3, a high-pressure compressor 4, a combustion chamber (not shown), a low-pressure turbine (not shown) and a high-pressure turbine (not shown).

[0015] The terms "upstream" and "downstream" are defined in relation to the circulation of gases in the turbomachine (in normal operating conditions) and along the longitudinal axis X. Similarly, the terms "radial", "internal" and "external" are defined in relation to a radial axis Z perpendicular to the longitudinal axis X and with regard to the distance from the longitudinal axis X.

[0016] The low-pressure compressor 3 and the low-pressure turbine are connected by a low-pressure shaft (not shown) and together form a low-pressure (LP) body. The high-pressure compressor 4 and the high-pressure turbine are connected by a high-pressure shaft (not shown) and together form a high-pressure (HP) body. The low-pressure shaft and the high-pressure shaft are centered on the longitudinal axis.

[0017] The turbomachine comprises a fan 5 which is arranged upstream of the gas generator 2. The fan 5 is driven in rotation directly by the low-pressure shaft or via a speed reducer (not shown). The fan 5 comprises a row of fan blades 6 extending radially outwards and distributed regularly around the longitudinal axis. The fan blades 6 are surrounded by an outer casing 7 which is carried by a fan casing 8. The outer casing 7 is centered on the longitudinal axis X.

[0018] According to one embodiment, the fan blades 6 can be of variable pitch.

[0019] With reference to Figure 1, the turbomachine 1 comprises a first annular vein, called primary vein 9 in which a primary flow (or hot flow) circulates and a second annular vein, called secondary vein 10 in which a secondary flow (or cold flow) circulates. The secondary vein 10 advantageously surrounds the primary vein 9. The primary vein 9 and the secondary vein 10 are separated by an annular inter-vein casing 11 arranged between the external casing 7 and an internal casing 11. The latter partly envelops the gas generator 2.

[0020] Advantageously, the primary vein 9 is delimited by a radially internal wall of the inter-vein casing 11 and a radially external wall of an internal casing. The latter is coaxial with the inter-vein casing 11 and surrounded by the inter-vein casing 11. Advantageously, the secondary vein 10 is delimited by a radially external wall 12 of the inter-vein casing 11 and a radially internal wall 13 of the external casing 7.

[0021] The primary flow passes through the compressors, the combustion chamber, and the turbines, then opens into a nozzle (not shown) towards the atmosphere.

[0022] With reference to FIG. 2, a discharge system 20 is arranged in the turbomachine so as to be able to take a portion of an air flow at the level of one or more members of the turbomachine and to eject this portion of the air flow into another air flow of the turbomachine.

[0023] Advantageously, the discharge system 20 is intended to take a portion of air from the high pressure compressor 4. The portion of air taken is a portion of the primary flow.

[0024] The discharge system 20 is arranged between the primary vein 9 and the secondary vein 10. More precisely, the discharge system 20 is mounted at the level of the radially external wall 12 of the inter-vein casing 11. The discharge system 20 is advantageously, but not limited to, mounted in line with the high-pressure compressor 4 so as to reduce the size. The portion of the primary flow is ejected into the secondary vein 10.

[0025] According to an exemplary embodiment, the discharge system 20 comprises at least one flow deflector 21 and a conduit 24.

[0026] The flow deflector 21 comprises a wall 25 from which a peripheral skirt 26 extends. Advantageously, but not limitingly, the wall 25 is circular and the peripheral skirt 26 is cylindrical with a circular section of axis of revolution A. Of course, the shape of the wall 25 and of the skirt 26 could be different such as rectangular.

[0027] The deflector 21 comprises an air inlet 27 and an air outlet 28. Advantageously, the air inlet 27 is formed by a free edge of the peripheral skirt 26. The air outlet 28 is advantageously formed by ejection channels 29 (shown in particular in FIG. 3) arranged in the wall 25.

[0028] With reference to Figures 2 to 4, the flow deflector 21 comprises a collar 35 secured to the peripheral skirt 26. The collar 35 extends in this example from the free end of the peripheral skirt 26 and surrounds the air inlet 27. The collar 35 allows the flow deflector 21 to be fixed to the duct 24. The collar 35 comprises holes 36 passing through the wall thereof on either side. The holes 36 are intended to receive removable fixing means 37 such as screws.

[0029] According to the example of Figure 2, the collar 35 is mounted advantageously, but not limitingly, opposite the radially internal surface 14 of the radially external wall 12 of the inter-vein casing 11.

[0030] The duct 24 is advantageously arranged in the inter-stream casing 11 (or in the “core” compartment of the turbomachine). The wall 25 and a portion of the peripheral skirt 26 are arranged in the secondary stream 10 so that the primary flow received from the compressor by the air inlet is ejected directly into the secondary stream 10 via the ejection channels 29. The peripheral skirt 26 defines an air flow passage between the air inlet 27 and the ejection channels 29.

[0031] The duct 24 comprises an air inlet (not shown) intended to be in fluid communication with the primary vein 9 and to receive a portion of the primary flow from the high-pressure compressor 4. The duct 24 also comprises an air outlet 32 ​​coupled to the air inlet 27 of the flow deflector 21. The duct 24 allows the passage of the hot air flow from the compressor to the flow deflector 21.

[0032] A regulating device 22 and an actuator 23 can be arranged in the conduit 24, or upstream of the conduit 24 in the vicinity of the primary vein 9.

[0033] In Figures 3 and 4, the wall 25 is provided with a plurality of ejection channels 29 capable of discharging a portion of the primary air flow into the secondary vein 10 where the secondary air flow circulates. The ejection channels 29 are configured so as to eject a discharge air flow Fc which does not come directly into contact with the walls 12 (IFD), 13 (OFD) of the secondary vein 10 and which does not disturb the flow or circulation of the secondary flow.

[0034] The wall 25 of the deflector has an arcuate or dome shape. The wall 25 has a substantially constant thickness of between 1 and 5 mm. In In particular, the wall 25 has a concave internal surface 30 facing the regulating device 22 of the discharge system 20 and a convex external surface 31 opposite the internal surface 30. The latter in the present example faces the secondary vein 10. The wall 25 here has a circular peripheral edge as stated previously.

[0035] With reference to Figure 3, the ejection channels 29 are formed in the wall 25 of the deflector 21. Each ejection channel 29 extends on either side thereof between the inner surface 30 and the outer surface 31. In the examples shown, the ejection channels 29 occupy almost the entire surface of the wall 25. Each ejection channel 29 has an inlet orifice 33 defined in the inner surface 30 and fluidly communicating with the passage of the deflector 21. Each ejection channel 29 comprises an outlet orifice 34 defined in the outer surface 31 and fluidly communicating with the secondary vein 10.

[0036] The ejection channels 29 here have a substantially constant circular section. Of course, the section of the channels 29 could have another shape. Here, the channels 29 have a diameter of between 2 and 3 mm (preferably of the order of 2.5 mm) so as to facilitate the manufacture of the flow deflector, adapt the discharge flow rate to be discharged and limit noise pollution. The length of these channels 29 is preferably between 1 mm and 6 mm. The dimension of the channels 29 will depend on the dimensions of the deflector (in particular the thickness of the wall) and the discharge flow rate to be discharged into the secondary vein 10.

[0037] The ejection channels 29 are arranged in several rows R1, R20, etc. Each row R1, R20 extends in an alignment direction (B) parallel or substantially parallel (plus or minus 5°) to a median plane PM of the flow deflector 21. In other words, the rows are parallel to each other. The median plane PM is parallel to the direction of flow of the air flow (here in this case the secondary flow in the installation situation). The median plane PM is in the plane of FIG. 3 and includes the axis of revolution A of the deflector 21.

[0038] The rows R1, R20 each advantageously form a discharge flow blade.

[0039] Each row R1, R20 comprises between 1 and 30 ejection channels 29. The channels 29 are spaced from each other by a distance for example between 0.5 and 3 mm to maintain mechanical strength of the wall 25 of the flow deflector. It is understood that the number of rows and the number of ejection channels 29 per row is a function on the one hand of the dimensions of the flow deflector 21 and the ejection channels 29 and on the other hand of the flow rate desired to pass through the deflector 21 when the valve is open.

[0040] As also illustrated in Figures 3 and 4, the ejection channels 29 are arranged so as to form lines L parallel to each other. The lines L are advantageously arranged transversely relative to the median plane PM. In particular, the lines L are oriented towards the lateral edges of the deflector 21. The lateral edges are arranged on either side of the median plane PM.

[0041] According to this embodiment example, the L lines are curved. The rounded shape of the L lines is accentuated by the spherical shape of the wall 25.

[0042] According to yet another advantageous but non-limiting characteristic, the lines L are symmetrical with respect to the median plane. These have a substantially V-shape with the tip of the V being arranged on the median plane PM.

[0043] The channels 29 are configured to discharge the air jet in the direction of flow of the secondary air flow.

[0044] Each ejection channel 29 has a central axis C. In the present example, the central axis C of each ejection channel 29 is oriented in a direction forming a first angle a defined with respect to an axis B parallel to the axis of revolution A of the deflector. In the present example, the axis B is vertical in the plane of FIG. 3. Each first angle a is measured in a vertical plane parallel to the median plane PM or to the longitudinal axis X (in the installation situation in the turbomachine).

[0045] Advantageously, each first angle a is between 0° and 90°. This allows the primary air flow leaving the deflector 21 to avoid the radially internal and external walls 12, 13 of the secondary vein 10.

[0046] Advantageously, the first angles α of each row decrease from upstream to downstream along the flow direction (or the longitudinal axis X when the discharge system 21 is installed in the turbomachine). In other words, the ejection channels 29 of the same row are oriented along a first angle α which decreases between a first channel of a row and the last channel of this row. The first angles α are then different. This variation is defined between an upstream edge and a downstream edge of the wall.

[0047] According to an advantageous but non-limiting characteristic, the variation is progressive so as not to create a disturbance in the secondary flow. In this way, the discharge air flow blades Fc passing through the ejection channels 29 are guided in a direction oriented in the direction of circulation of the secondary flow.

[0048] According to one embodiment, the ejection channels 29 of each row are oriented at the same angle a so as to form a discharge air flow blade Fc. In other words, the ejection channels 29 of the same row are oriented at an identical angle a. This configuration would prevent the discharge flow blade Fc from coming into contact with the radially internal wall 13 and / or a thrust reverser that the turbomachine comprises.

[0049] According to an exemplary embodiment and as shown in Figure 4, the projection of the axes C of the ejection channels 29 of each row in a projection plane PP perpendicular to the median plane PM forms a second angle p with a straight line parallel to the median plane. Such a configuration makes it possible to maximize the frontal mixing surface between the flow jet at the outlet of the deflector and the secondary flow in order to improve mixing.

[0050] Advantageously, the second angles p of each row are constant. A row has a single angle on each side of the median plane. Alternatively, the second angles p of each row are not constant.

[0051] According to an advantageous characteristic, the second angles p vary in an increasing manner from the median plane PM towards the lateral edge opposite the median plane. The direction of this increasing variation is perpendicular to the median plane PM. In other words, the second angles p vary in the same curved line towards the edge of the wall 25. Between an ejection channel of one row and an ejection channel of a neighboring row, the second angle p increases from the median plane. This configuration allows a better distribution of the discharge air flow in the flow of the air flow.

[0052] As can be seen in Figure 4 and in a non-limiting manner, the curved lines L, respectively symmetrical (on either side), substantially form a V with the tip of the V crossed by the median plane. This accentuates the tangential component of the channels and promotes the distribution of the discharge air flow towards the edges of the deflector.

[0053] Advantageously, the variation of the second angle p is for example progressive for better distribution of the hot jet.

[0054] The values ​​of the second angles P are symmetrical with respect to the median plane PM. This allows for a homogeneous distribution of the flow. This distribution could be non-symmetrical.

[0055] The second angle P is between 0° inclusive and 90° inclusive. The amplitude of the variation of the second angle P can be defined according to the need to dilute the discharge air flow in the secondary flow. The greater the variation of the second angle P, the greater the dilution will be. A variation amplitude of + / - 30° between the median plane and the row furthest from the median plane, on either side of the median plane, can nevertheless provide sufficient dilution in certain configurations.

[0056] Thus, when the discharge air flow Fc is ejected into the secondary vein 10, it is oriented along several blades with a substantially parabolic shape which avoids thermal shocks with the environment of the discharge system 20. The circulation and flow of the cold air flow F is not disturbed. The second angles p allow a better distribution of the flow in an azimuthal (or tangential) direction of the grid.

Claims

Claims [1] Flow deflector (21) of a discharge system (20) of a compressor (4, 5) of a turbomachine (1) with a double flow of longitudinal axis (X), the flow deflector (21) comprising a wall (25) provided with a plurality of ejection channels (29) capable of discharging a discharge air flow from the compressor into a vein (9, 10) of the turbomachine (1) in which an air flow circulates in a flow direction, the ejection channels (29) of axes (C) being arranged in several rows (R1, R20) in alignment directions (B) substantially parallel to a median plane (PM) of the flow deflector (21) which is substantially parallel to the flow direction and being configured so as to eject the discharge air flow in the flow direction, the axes (C) each being oriented following a first direction forming a first angle (a) relative to an axis (B) parallel to an axis of revolution of the flow deflector,characterized in that the projection of the axes of the ejection channels (29) of each row in a projection plane (PP) perpendicular to the median plane (PM) forms a second angle (P) with a straight line parallel to the median plane (PM), and the second angle (P) increases from the median plane (PM) towards the edge of the deflector in a direction perpendicular to the median plane (PM)., [2] Deflector (21) according to claim 1, characterized in that the ejection channels (29) of each row have a circular cross section. [3] Deflector (21) according to one of claims 1 or 2, characterized in that the values ​​of the second angles (P) are symmetrical with respect to the median plane. [4] Deflector (21) according to one of the preceding claims, characterized in that the variation of the second angle (P) is progressive. [5] Deflector (21) according to one of the preceding claims, characterized in that the second angle (P) is constant in the same row on either side of the median plane. [6] Deflector (21) according to one of the preceding claims, characterized in that the ejection channels (29) are arranged so as to form curved lines (L). substantially parallel to each other, transverse to the median plane (MP) and symmetrical to the median plane (MP). [7] Deflector (21) according to one of the preceding claims, characterized in that the first angles (a) of each row are constant. [8] Deflector (21) according to one of claims 1 to 6, characterized in that each first angle (a) of the same row varies by decreasing between an upstream edge and a downstream edge of the wall (25) according to the direction of flow of the air flow (F). [9] Deflector (21) according to one of claims 1 to 8, characterized in that the second angle (p) is between 0° inclusive and 90° inclusive. [10] Double flow turbomachine (1) comprising at least one deflector according to any one of the preceding claims.

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