Turbine engine blade assembly

Abstract

The invention relates to a blade (30) of a turbine engine (10) for mounting around a longitudinal axis (X), comprising: a first blade (31) and a second blade (31 ') which are circumferentially adjacent, extend radially with respect to said longitudinal axis (X), and each blade has an aerodynamic profile axially defined by an upstream leading edge (51, 51') and a downstream trailing edge (52, 52 '), said leading edges (51, 51', 51 ', 52', 52 ', 52') being connected to the first blade (31) and the second blade (31 '). The leading edge (51, 51 ') and the trailing edge (52, 52') are separated by a chord length (Cx), each blade (31, 31 ') further comprising a lower surface wall (54, 54') and an upper surface wall (53, 53 ') opposite the lower surface wall (54, 54'), the lower surface wall (54, 54 ') and the upper surface wall (53, 53') each connecting the leading edge (51, 51 ') and the trailing edge (52, 52'); a platform (32) comprising a flow channel surface (321), said platform (32) being intended to define a main flow channel (21A) for the flow of fluid in a main flow direction (S1) from said leading edge (51, 51 ') of each blade (31, 31') to said trailing edge (52, 52 '); the platform (32) has a suction opening (35, 35 ') and a spray opening (36, 36') disposed downstream of the suction opening (35, 35 ').

Description

Technical Field

[0001] This invention relates to the field of turbine engines, such as turboprop engines or turbojet engines.

[0002] More specifically, the present invention relates to the field of turbines for aircraft turbine engines, and even more specifically to blades for nozzle guides (distributors) or impellers (moving wheels) of such turbines. Background Technology

[0003] A conventional aircraft turbine engine turbine comprises one or more stages, each consisting of a nozzle guide and an impeller. The nozzle guide includes stationary blades connected to the casing via their radially outer ends and circumferentially distributed around the turbine's longitudinal central axis, forming a stator annulus. The impeller includes a disk and blades connected to the disk via their radially inner ends and circumferentially distributed around the disk. The nozzle guide of one stage is configured such that the fluid flow entering that stage (typically including gas from the combustion chamber) is accelerated and deflected by the stator blades toward the blades of the stage impeller, thereby driving its rotation about the longitudinal central axis.

[0004] Typically, each nozzle guide and impeller blade of a turbine includes a blade body and two platforms that radially define the circumferential portion of an annular main flow channel between them, in which the blade body extends. Fluid flowing through the turbine primarily flows in this main flow channel.

[0005] During the operation of a conventional turbine, the interaction between the fluid and the nozzle guide and impeller generates vortices at the blade platform, forming what is known as a "secondary flow".

[0006] To explain this phenomenon, Figure 1 A portion of two blades 1A and 1B of the turbine nozzle guide 1 is shown, which are circumferentially adjacent to each other. Figure 1 More specifically, the radially inner portions of the blade body 2 and platform 3 of each blade 1A and 1B are shown. The blade body 2 of each blade 1A and 1B includes a leading edge 4, a trailing edge 5, a lower surface 6 (intrados), and an upper surface 7 (extrados). The platform 3 of each blade 1A and 1B radially inward defines the circumferential portion of an annular main flow channel in which fluid flows from the leading edge 4 to the trailing edge 5 of the blade body 2 along the main flow direction S1.

[0007] Considering the typical viscosity of the fluid circulating in the turbine mains channel, its flow along the surface of platform 3 has a velocity gradient GV1, such that the lower the velocity of the fluid layer near that surface, the closer the layer is to that surface. The fluid flowing in the mains channel is also affected by a pressure gradient GP1, which in this example points from the lower surface 6 of the blade 2 of blade 1B to the upper surface 7 of the blade 2 of blade 1A. The pressure gradient GP1 is generally sufficient to deflect the fluid layer flowing near the surface of platform 3.

[0008] This results in different types of vortices. The first type, called the "horseshoe vortex" T1, appears as two counter-rotating branches distributed on both sides of the blade 2. The second type, called the "channel vortex" T2, develops between two circumferentially adjacent blades 2. The third type, called the "angle vortex" T3, extends along the connecting line between the blade 2 and the platform 3 of each blade.

[0009] These secondary flows, T1, T2, and T3, typically occur at the root and tip of blade 2. Their direction is not the main flow direction S1 of the fluid through the main channel, thus leading to reduced turbine engine efficiency and increased kerosene consumption. Similar secondary flows also occur in the turbine impeller.

[0010] Therefore, there is a need to provide a blade that reduces the secondary flow upstream of the blade, thereby reducing adverse effects that negatively impact turbine engine efficiency. Summary of the Invention

[0011] The present invention aims to at least partially address the aforementioned shortcomings of the prior art.

[0012] Therefore, the present invention relates to a turbine engine blade for mounting around a longitudinal axis X, comprising:

[0013] • A first blade and a second blade, which are circumferentially adjacent and extend radially relative to the longitudinal axis X, and each blade has an aerodynamic profile defined axially by an upstream leading edge and a downstream trailing edge, the leading edge and the trailing edge being separated by a chord length, and each blade also includes a lower surface wall and an upper surface wall opposite to the lower surface wall, the lower surface wall and the upper surface wall respectively connecting the leading edge and the trailing edge;

[0014] A platform, including a flow channel surface from which each blade extends, the platform being designed to define a main flow channel for fluid to flow in a main direction from the leading edge to the trailing edge of each blade, the platform having an intake opening and an injection opening disposed downstream of the intake opening.

[0015] According to the invention, the intake opening opens between the leading edges of two circumferentially adjacent blades, and the injection opening extends on the flow channel surface in a principal direction substantially perpendicular to the longitudinal axis, and opens over a portion of a substantially rectangular region extending beyond:

[0016] • Length L1, measured along the main direction from the trailing edge of the first blade, corresponds to a predetermined inter-blade distance, which is measured circumferentially between the trailing edges of the first and second blades.

[0017] • Width L2, perpendicular to the main direction α, corresponding to a distance less than or equal to one-quarter of the chord length, located upstream and / or downstream of the trailing edge.

[0018] Therefore, the present invention provides a novel and innovative method to at least partially address some of the shortcomings of the prior art.

[0019] To be as effective as possible, the shape and location of the injection opening must meet three criteria: it must be located in a low-pressure region to facilitate suction at the sampling port near the lower surface wall, generating minimal head loss to efficiently draw flow near the leading edge, and it must facilitate the injection of flow into the channel in a direction as close as possible to the main flow S1, while minimizing disturbance. Therefore, by implementing an injection opening extending into the region defined by this invention, it is possible to re-inject most of the flow radially downstream of the blade near the trailing edge without causing disturbance in the re-injection zone, thus achieving a passive system based on the upstream and downstream pressure difference.

[0020] Furthermore, the shape of this jet opening allows it to be well positioned in low-pressure areas to draw in as much flow as possible, and its fitted shape minimizes air disturbance during jetting, which reduces head loss during mixing.

[0021] This can also reduce losses at the downstream blade by reducing the angle and Mach number distortion generated by the secondary flow near the blade wall and greatly reducing the intensity of the eddy currents leaving the blade.

[0022] According to a particular aspect of at least one embodiment of the invention, the injection opening opens downstream of the trailing edge of each of two circumferentially adjacent blades.

[0023] According to a particular aspect of at least one embodiment of the invention, the jet opening has a quadrilateral shape, an oblong shape, a circular shape, an oval shape, or a "droplet" shape.

[0024] According to a particular aspect of at least one embodiment of the invention, the injection opening has a rectangular shape, a parallelogram shape, a rhombus shape, or a trapezoidal shape.

[0025] According to a particular aspect of at least one embodiment of the invention, the blade includes an internal channel formed between the intake opening and the injection opening.

[0026] According to a particular aspect of at least one embodiment of the invention, the internal channel has a jetting portion having a ramp near the jetting opening, the ramp of the jetting portion having an inclination that gradually decreases toward the jetting opening relative to the flow channel surface, such that the jet exiting from the internal channel is substantially parallel to the fluid flowing from the leading edge to the trailing edge of each blade along the main flow direction.

[0027] This avoids jet separation, which would otherwise result in pressure head loss and efficiency reduction in the main flow path.

[0028] According to a particular aspect of at least one embodiment of the invention, the platform is an inner platform, the flow channel surface of the inner platform being adapted to radially inward define the main flow channel.

[0029] According to a particular aspect of at least one embodiment of the invention, the internal channel has a continuous internal tube wall.

[0030] In addition, the inner tube wall is smooth.

[0031] In other words, the internal channel has an internal tube wall that is free of roughness or protrusions, i.e., without discontinuities or abrupt changes in slope.

[0032] This shape can therefore limit the formation of additional eddies and limit head loss.

[0033] According to at least one specific aspect of an embodiment of the invention, the inhalation opening is located near the leading edge.

[0034] According to a specific aspect of at least one embodiment of the invention, the suction opening has at least one hole, the shape of which is selected from:

[0035] • Oval shape;

[0036] Spoon-shaped;

[0037] • Groove shape; or

[0038] • Biconvex shape.

[0039] The present invention further relates to a turbine for a turbine engine, comprising:

[0040] • Nozzle guide, including at least one blade according to any of the foregoing embodiments, and / or

[0041] • Impeller, including at least one blade according to any of the foregoing embodiments.

[0042] The present invention also relates to a turbine engine including a turbine according to the foregoing embodiments. Attached Figure Description

[0043] The invention and its various advantages will be more readily understood by reading the following illustrative and non-limiting description of its embodiments and the accompanying drawings, wherein:

[0044] [ Figure 1 [This is a partial schematic perspective view of the nozzle guide of a conventional turbine used in an aircraft turbine engine, showing the secondary flow that occurs during turbine engine operation;]

[0045] [ Figure 2 [This is a schematic axial sectional view of a propulsion assembly for an aircraft;]

[0046] [ Figure 3 [This is a partial schematic axial cross-sectional view of the low-pressure turbine of a turbine engine;]

[0047] [ Figure 4 [A] is a schematic side sectional view of a blade according to a first embodiment of the present invention;

[0048] [ Figure 5 [Illustration] is a schematic top cross-sectional view of a blade according to a first embodiment of the present invention;

[0049] [ Figure 6 [A] is a partial schematic perspective view of a blade according to a first embodiment of the present invention; and

[0050] [ Figure 7 [Illustration] is a partial schematic perspective view of a blade according to a second embodiment of the present invention.

[0051] Detailed Description of Embodiments of the Invention

[0052] The accompanying diagram includes reference frames L, R, and C, which define the longitudinal (or axial), radial, and circumferential directions that are orthogonal to each other, respectively.

[0053] Figure 2 An aircraft propulsion assembly 10 is shown, which includes a turbine engine 11 rectified by a nacelle 12. In this example, the turbine engine 11 is a dual-rotor turbofan engine.

[0054] In the following text, the terms "upstream" and "downstream" are defined relative to the general direction S1 through which the airflow passes when the propulsion assembly 10 is propelled.

[0055] The turbofan engine 11 has a longitudinal central axis X, around which its various components extend, in this example from upstream to downstream: fan 13, low-pressure compressor 14, high-pressure compressor 15, combustion chamber 16, high-pressure turbine 17, and low-pressure turbine 18. The low-pressure compressor 14, high-pressure compressor 15, combustion chamber 16, and high-pressure turbine 17 and low-pressure turbine 18 constitute a gas generator.

[0056] During operation of the turbofan engine 11, an airflow enters the propulsion assembly 10 through an intake upstream of the nacelle 12, passes through the fan 13, and then splits into a central main flow and a secondary flow. The main flow flows into a main flow channel 21A for circulating gas through the gas generator. The secondary flow flows into a secondary flow channel 21B surrounding the gas generator and is radially outwardly defined by the nacelle 12.

[0057] In one exemplary embodiment, the low-pressure turbine 18 is referred to below. Figure 3 The above, Figure 3 The turbine 18 is shown along a radial plane containing the longitudinal central axis X.

[0058] The longitudinal central axis X is also the axis of rotation of the turbine rotor 18.

[0059] In this example, turbine 18 includes four stages, each stage including nozzle guide 25 and impeller 26.

[0060] In a manner known per se, the impellers 26 are axially assembled to each other via annular flanges 27 to form the rotor of the turbine 18. The nozzle guide 25 is connected to the casing 28 to form the stator of the turbine 18.

[0061] Each nozzle guide 25 includes multiple blades 30 circumferentially distributed around the axis X. Refer to the nozzle guide 25 of the last stage of turbine 18 ( Figure 3 Only one blade 30 is shown in the image. Each blade 30 includes a first blade body 31 and a second blade body 31', an inner platform 32, and an outer platform 33. Each blade 30 is connected to the housing 28 via a connecting element integral with its outer platform 33.

[0062] Each impeller 26 includes a disk and multiple blades circumferentially distributed around the axis X. Refer to the impeller 26 of the last stage of turbine 18 ( Figure 3 (Only one blade is shown in the image), each blade includes a first blade body and a second blade body, an inner platform and an outer platform. Each blade is connected to the disc via a blade root integral with its inner platform.

[0063] For each blade 30 of the nozzle guide 25, platforms 32 and 33 each include a first surface from which each blade 31, 31' extends, and this surface defines a circumferential portion of the main flow channel 21A, in which the main flow occurs. Thus, the first surface of the inner platform 32 of each blade 30 defines the main flow channel 21A radially inward, while the first surface of the outer platform 33 of each blade 30 defines the main flow channel 21A radially outward.

[0064] Similarly, for each impeller blade, each platform includes a first surface from which each blade body extends, and this surface defines a circumferential portion of the main flow channel 21A. Thus, the first surface of the inner platform of each blade defines the main flow channel 21A radially inward, while the first surface of the outer platform of each blade defines the main flow channel 21A radially outward.

[0065] exist Figure 3 In the turbine 18, the main channel 21A is therefore generally annular.

[0066] Now combined Figures 4 to 6 The first embodiment of the present invention is described below.

[0067] It should be noted that this first embodiment is applicable to nozzle guide vanes or turbine impeller blades of a turbine engine.

[0068] As shown in these different figures, each blade 30 includes:

[0069] • The first blade 31 and the second blade 31' are circumferentially adjacent and extend radially relative to the longitudinal axis X;

[0070] Platform 32 includes a flow channel surface 321 from which each blade 31, 31' extends. The platform is designed to define a main flow channel 21A for fluid to flow in the direction S1 from the leading edge 51 to the trailing edge 52 of each blade. The platform 32 has an intake opening 35 and an injection opening 36 disposed downstream of the intake opening 35.

[0071] Here, platform 32 is an inner platform, and the flow channel surface 321 of the inner platform 32 radially defines the main flow channel 21A.

[0072] In this embodiment, the blade includes an internal channel 34 formed between the intake opening 35 and the injection opening 36. The internal channel 34 has a continuous internal wall to prevent the generation of additional eddies and to limit pressure, thereby reducing head loss.

[0073] In other words, the internal channel has a smooth internal tube wall.

[0074] In other words, the internal channel has an internal pipe wall that has no roughness or protrusions that could interfere with fluid flow.

[0075] The first blade 31 has an aerodynamic profile defined axially by an upstream leading edge 51 and a downstream trailing edge 52, which are separated by a chord length Cx. The first blade 31 also includes a lower surface wall 54 and an upper surface wall 53 opposite to the lower surface wall 54, such that the lower surface wall 54 and the upper surface wall 53 respectively connect the leading edge 51 and the trailing edge 52.

[0076] The second blade 31' itself has an aerodynamic profile defined axially by an upstream leading edge 51' and a downstream trailing edge 52', which are separated by a chord length Cx'. The second blade 31' also includes a lower surface wall 54' and an upper surface wall 53' opposite to the lower surface wall 54', such that the lower surface wall 54' and the upper surface wall 53' each connect the leading edge 51' and the trailing edge 52'.

[0077] According to the present invention, the inhalation opening is located between the leading edges 51, 51' of two circumferentially adjacent blades 31, 31'.

[0078] Furthermore, according to the invention, the injection opening 36 extends along a main direction α that is substantially perpendicular to the longitudinal axis X on the flow channel surface 321 and opens on a portion of a substantially rectangular region 9.

[0079] According to the invention, the substantially rectangular region 9 extends across:

[0080] • Length L1, measured along the main direction α from the trailing edge 52 of the first blade, corresponds to a predetermined inter-blade distance, which is measured circumferentially between the trailing edges 52 of the first blade body 31 and the trailing edges 52' of the second blade body 31', and

[0081] • Width L2, perpendicular to the principal direction α, corresponding to a distance less than or equal to one-quarter of the chord length Cx, located upstream and / or downstream of the trailing edge 52.

[0082] Therefore, the region supported by the platform connected to the blade extends in two dimensions: in the first dimension it extends along the direction between the blades of the two blades, and in the second dimension (orthogonal to the first dimension) it extends between a point located upstream of the trailing edge at a distance less than or equal to one-quarter of the chord length Cx and a point located downstream of the trailing edge at a distance less than or equal to one-quarter of the chord length Cx.

[0083] In other words, the entire injection opening is formed at the surface of the flow channel so as to be positioned within this generally rectangular region 9.

[0084] Therefore, the size of the injection opening is less than or equal to the size of region 9.

[0085] The injection opening 36 here has a quadrilateral shape, more specifically a parallelogram shape.

[0086] According to other embodiments, it is particularly conceivable that the injection opening has a rectangular shape, a rhomboid shape, a square shape, or a trapezoidal shape.

[0087] It can also provide, such as Figure 7 The embodiment shown has an injection opening 36' that is substantially elliptical in shape.

[0088] It is also possible to provide jet openings with oblong, circular, oval, or "teardrop" shapes.

[0089] In this embodiment, the injection opening 36 opens downstream of the trailing edge 52, 52' of each of the two circumferentially adjacent blades 31, 31'.

[0090] like Figure 4 and Figure 6 Specifically, the internal channel 34 has a jetting portion 360, which has a ramp near the jetting opening 36. The slope of the jetting portion 360 relative to the flow channel surface 321 gradually decreases toward the jetting opening 36, such that the jet discharged from the internal channel 34 is substantially parallel to the fluid flowing along the main flow direction S1 from the leading edge 51, 51' of each blade 31, 31' to its trailing edge 52, 52'.

[0091] In other words, moving outward from the injection opening 36, the slope of the injection section 360 increases by moving upstream toward the internal channel 34, opposite to the direction of the fluid intended to circulate within the internal channel 34, until the end of the injection section 360.

[0092] like Figure 5 As specifically shown, in the first embodiment, the intake opening 35 is located near the leading edge 51, 51' of each blade.

[0093] Figure 4 The suction opening 35 shown has an oval shape oriented along a main direction that forms an angle of approximately 30 degrees with the direction passing through the leading edge 51 and the trailing edge 52, and also forms an angle of approximately 30 degrees with the direction configured to pass through the leading edge 51 of the first blade of the two blades 30 and the leading edge of the second blade of the two blades 30'.

[0094] In this embodiment, the internal channel also has a suction portion 350, which has a ramp near the suction opening 35. The slope of the suction portion 350 relative to the flow channel surface 321 gradually decreases toward the suction opening 35. In other words, as it moves outward from the suction opening, the slope of the suction portion increases as it moves downstream toward the internal channel 34 until it reaches the end of the suction portion.

[0095] The second embodiment has an inhalation opening 35' (as shown in the example). Figure 7 (As shown) it has a "droplet" shape.

[0096] According to other embodiments not shown, the suction opening may have an oblong shape, a circular shape, or an oval shape.

Claims

1. A blade (30) of a turbine engine (10) for mounting about a longitudinal axis (X), comprising: • A first blade (31) and a second blade (31') are circumferentially adjacent and extend radially relative to the longitudinal axis (X). Each blade has an aerodynamic profile defined axially by an upstream leading edge (51, 51') and a downstream trailing edge (52, 52'), which are separated by a chord length (Cx). Each blade (31, 31') also includes a lower surface wall (54, 54') and an upper surface wall (53, 53') opposite to the lower surface wall (54, 54'), which respectively connect the leading edge (51, 51') and the trailing edge (52, 52'). • Platform (32), including flow channel surface (321), said platform (32) is intended to define a main flow channel (21A) for fluid to flow along the main flow direction (S1) from the leading edge (51, 51') of each blade (31, 31') to the trailing edge (52, 52'); The platform (32) has an intake opening (35, 35') and an injection opening (36, 36') disposed downstream of the intake opening (35, 35'). The characteristic feature is that the intake opening (35, 35') opens between the leading edges (51) of two circumferentially adjacent blades (31, 31'), and the injection opening (36, 36') extends on the flow channel surface (321) in a principal direction (α) substantially perpendicular to the longitudinal axis (X), and opens on a portion of a substantially rectangular region (9) extending beyond: • Length (L1), measured along the main direction (α) from the trailing edge (52) of the first blade (31), corresponding to a predetermined inter-blade distance, which is measured circumferentially between the trailing edge (52) of the first blade (31) and the trailing edge (52') of the second blade (31'), and • Width (L2), perpendicular to the main direction (α), corresponding to a distance less than or equal to one-quarter of the chord length (Cx), located upstream and / or downstream of the trailing edge (52).

2. The blade according to claim 1, characterized in that, The injection opening (36') opens downstream of the trailing edge (52, 52') of each of the two circumferentially adjacent blades (31, 31').

3. The blade according to any one of the preceding claims, characterized in that, The jet opening (36) has a quadrilateral shape, an oblong shape, a circular shape, an oval shape, or a "teardrop" shape.

4. The blade according to any one of the preceding claims, characterized in that, Includes an internal channel (34) formed between the intake opening (35, 35') and the injection opening (36, 36').

5. The blade according to the preceding claim, characterized in that, The internal channel (34) has a jet section (360) with a ramp near the jet opening (36, 36'). The slope of the jet section (360) relative to the flow channel surface (321) gradually decreases toward the jet opening (36, 36'), such that the jet discharged from the internal channel (34) is substantially parallel to the fluid flowing along the main flow direction (S1) from the leading edge (51, 51') of each blade (31, 31') to the trailing edge (52, 52').

6. The blade according to claim 4 or 5, characterized in that, The internal channel (34) has a continuous internal tube wall.

7. The blade according to any one of the preceding claims, characterized in that, The platform (32, 33) is an inner platform (32), and the flow channel surface (321) of the inner platform (32) is adapted to radially inward define the main flow channel (21A).

8. The blade according to any one of the preceding claims, characterized in that, The inhalation opening (35, 35') is located near the leading edge (51, 51').

9. The blade according to any one of the preceding claims, characterized in that, The suction opening (35, 35') has a shape selected from the following: • Oval shape; • Spoon-shaped; • Groove shape; or • Biconvex shape.

10. A turbine for a turbine engine, comprising: • Nozzle guide, comprising at least one blade according to any one of claims 1 to 9, and / or • Impeller, comprising at least one blade according to any one of claims 1 to 9.

11. A turbine engine comprising the turbine according to claim 10.

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