Guide vane with slots
By introducing through slots and a double convexity structure into the guide vanes, the airflow separation problem in the turbine was solved, the aerodynamic performance was improved, and the overall efficiency of the turbine was enhanced.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SAFRAN AIRCRAFT ENGINES SAS
- Filing Date
- 2024-11-04
- Publication Date
- 2026-05-29
AI Technical Summary
The separation of airflow from the guide vanes in a turbine leads to aerodynamic and head losses, affecting turbine performance and being related to the turbine's operating mode.
A double convex structure that connects the slot and the blade is designed in the guide vane to prevent airflow separation and improve aerodynamic performance.
It effectively prevents airflow separation, improves the aerodynamic performance of the turbine, and is unaffected by the turbine's operating mode.
Smart Images
Figure CN122122370A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the general field of aircraft turbines, and more specifically to the general field of turbine housing guide vanes.
[0002] This disclosure relates more specifically, but not exclusively, to exhaust housing guide vanes. Background Technology
[0003] The operation of a turbine causes airflow within the turbine to pass between the rotor blades and the stator blades or the housing guide blades.
[0004] Because the guide vanes of the housing have a fixed orientation relative to the housing, the airflow has an incident angle relative to the vanes, which varies between different operating modes of the turbine.
[0005] In certain operating modes, changes in the angle of incidence of airflow in a turbine relative to the casing blades can cause airflow separation downstream of the blades.
[0006] This airflow separation downstream of the blades results in aerodynamic and / or head losses, leading to reduced turbine performance. Summary of the Invention
[0007] One objective of this disclosure is to solve the problem of airflow separation from the guide vane, regardless of the turbine's operating state.
[0008] Therefore, according to one aspect of this disclosure, a turbine guide vane assembly is provided, in which airflow flows. The assembly includes: - The inner ring extending along the longitudinal axis XX - The outer ring located radially outside the inner ring, and - A guide vane, which extends radially from the inner ring to the outer ring in the radial direction. The guide vane includes a leading edge and a trailing edge, the trailing edge being located downstream of the leading edge in the direction of airflow. The guide vane includes an arched back wall and an arched belly wall extending from the leading edge to the trailing edge, respectively. The guide vane has a cross-section in a transverse plane orthogonal to the radial direction, and the arched back wall and the arched belly wall each form two convex lines in the cross-section.
[0009] The guide vane also includes a through slot, which is at least partially formed in the arched back wall and extends over the entire height of the guide vane.
[0010] The slots formed in the blades and the double convexity of the blades prevent airflow separation on the arched back wall of the blades, regardless of the turbine's operating mode, or in other words, regardless of the angle of incidence of the airflow relative to the blades.
[0011] Furthermore, the slots formed in the casing blades and the convexity of the blades improve the aerodynamic performance of the turbine, regardless of the turbine's operating mode, and do not affect the operating mode where there is no airflow separation on blades without slots.
[0012] Advantageously but optionally, the component includes at least one of the following features, either individually or in any combination: - The slot includes an inlet and an outlet, with the outlet leading to the arch back wall and located downstream of the inlet in the direction of airflow; - The leading edge is formed by the upstream point with the smallest radius of curvature on each section of the guide vane, and the trailing edge is formed by the downstream point with the smallest radius of curvature on each section of the guide vane; - The slot divides the guide vane into a main portion including a trailing edge and a secondary portion, wherein the slot includes a main wall shared with the main portion and a secondary wall shared with the secondary portion; - At the entrance of the slot, the main wall of the slot has a first direction in a plane orthogonal to the radial extension direction of the guide vane, the first direction forming an angle of 45°+ / -25° with respect to a second direction orthogonal to the main cross section of the guide vane. - The distance between the entrance and the leading edge is + / - 10% of the curve length of the arch wall from the leading edge to the trailing edge; - At the outlet, the main wall and the arched back wall of the guide vane are tangentially continuous; - The distance between the exit and the leading edge is between 20% and 60% of the curved distance of the arch back wall from the leading edge to the trailing edge; - The width of the slot is equal to the diameter of the inscribed circle within the slot, and each inscribed circle is tangent to the primary wall and the secondary wall. The width of the outlet is equal to or less than the width of the inlet. - The component includes multiple guide vanes, each guide vane including the aforementioned slot.
[0013] According to another aspect, an exhaust housing is proposed, which is formed from the above-mentioned components.
[0014] According to another aspect, a turbine is proposed, the turbine including the aforementioned exhaust casing.
[0015] According to another aspect, an aircraft is proposed, which includes the aforementioned turbine. Attached Figure Description
[0016] Other features, purposes, and advantages will become apparent from the following description, which is purely illustrative and non-limiting and must be read with reference to the accompanying drawings, in which: Figure 1 The aircraft is shown schematically.
[0017] Figure 2 A schematic cross-sectional view of the aircraft's propulsion assembly is shown.
[0018] Figure 3 A perspective view of a portion of an exhaust housing according to an embodiment of the present disclosure is shown.
[0019] Figure 4a and Figure 4b Cross-sections of a guide vane without a slot and a guide vane with a slot, according to one embodiment of the present disclosure, are shown.
[0020] Figure 5 A perspective view of a guide vane with a slot according to an embodiment of the present disclosure is shown.
[0021] In all the accompanying drawings, similar elements have the same reference numerals. Detailed Implementation
[0022] aircraft For example in Figure 1 As shown, aircraft 100 is a machine configured to take off and travel in the air, and can be, for example, a civilian or military aircraft, or even a helicopter. Aircraft 100 includes a frame, which, in the case of an aircraft, consists of a fuselage, a wing configuration including two wings, a tail, flight control surfaces, and landing gear.
[0023] Propulsion components For example in Figure 2 As shown, the propulsion assembly 1 includes an engine 2 (or turbine) and optionally a nacelle 3 in embodiments with a ducted engine. The propulsion assembly 1 has a main direction extending along a longitudinal axis XX. The propulsion assembly 1 is configured to be fixed to the frame of the aircraft 100, for example, under its wing by means of a pylon (or mast) in the case of an aircraft. The propulsion assembly 1 may also be mounted on the wing of the aircraft or at the rear of its fuselage, or even integrated into its fuselage.
[0024] Engine 2 may be a ducted twin-shaft and direct-drive turbofan engine as described below, but may also include different numbers of shafts and / or streams, and / or another type of turbojet engine, such as a geared turbofan engine or a turboprop engine, with or without an afterburner, whether ducted or unducted.
[0025] Unless otherwise stated, the terms "upstream" and "downstream" are used with reference to the overall airflow direction through the propulsion assembly 1 during operation. Similarly, the axial direction corresponds to the direction of the longitudinal axis XX, and the radial direction is the direction perpendicular to and intersecting the longitudinal axis XX. A circumference is understood as a circle belonging to the radial plane and whose center belongs to the longitudinal axis XX. A tangential or circumferential direction is the direction tangential to the circumference: the tangential or circumferential direction is perpendicular to the longitudinal axis XX but does not cross it. Finally, the adjectives "inner" (or "internal") and "outer" (or "external") are used with reference to the radial direction, such that the inner portion of the element is closer to the longitudinal axis XX in the radial direction than the outer portion of the same element.
[0026] engine The engine 2 includes, from upstream to downstream, a fan 20, an engine housing 21, a compressor section 22 including a low-pressure compressor 220 and a high-pressure compressor 221, a combustion chamber 23, a turbine section 24 including a high-pressure turbine 240 and a low-pressure turbine 241, and an exhaust housing 25.
[0027] Compressor section 22 includes a series of stages, each stage including an impeller (rotor) rotating in front of the impeller (stator). Turbine section 24 also includes a series of stages, each stage including an impeller (stator) with an impeller (rotor) rotating behind the impeller (stator).
[0028] The rotor components of the fan 20, the low-pressure compressor 220, and the low-pressure turbine 241 are connected together by a low-pressure shaft 27 extending along the longitudinal axis XX, thereby forming a low-pressure body. The rotor components of the high-pressure compressor 221 and the high-pressure turbine 240 are connected together by a high-pressure shaft 28 extending along the longitudinal axis XX, thereby forming a high-pressure body. The low-pressure shaft 27 is generally housed within and coaxial with the high-pressure shaft 28 along its length.
[0029] The compressor section 22, combustion chamber 23 and turbine section 24 are surrounded by engine housing 21, and the stator components of low-pressure compressor 220, high-pressure compressor 221, high-pressure turbine 240 and low-pressure turbine 241 are connected to engine housing 21.
[0030] Engine housing 21 defines a main flow path A through which the rotor and stator components of low-pressure compressor 220, high-pressure compressor 221, low-pressure turbine 241, and high-pressure turbine 240 extend. Main flow path A completely passes through engine housing 21. Therefore, the stator components in main flow path A can form guides (or outlet guide vanes (OGVs)). In this way, the airflow flowing in main flow path A is deflected by the rotating rotor components and rectified by the stator components fixed relative to engine housing 21 defining main flow path A.
[0031] The exhaust housing 25 is connected to the engine housing 21 downstream of the turbine section 24. The exhaust housing 25 is fixedly mounted on the engine housing 21. The exhaust housing 25 is described in more detail below.
[0032] The longitudinal axis XX defines the rotation axis of the rotor components of the fan 20, the compressor section 22, and the turbine section 24. In other words, it defines the rotation axis of the low-pressure body and the high-pressure body, which can each be driven to rotate about the longitudinal axis XX relative to the engine housing 21.
[0033] In the embodiment of the ducted engine, the nacelle 3 extends radially outward of the engine 2 entirely around the longitudinal axis XX to surround and define a secondary flow path B around the engine casing 21. The upstream portion of the nacelle 3 also defines an airflow inlet through which the fan 20 draws in airflow passing through the propulsion assembly 1. The nacelle 3 is attached and secured to the aircraft 100 by means of a mast.
[0034] During operation, fan 20 draws in airflow, a portion of which flows through the main flow path A directly through engine housing 21, is continuously compressed in compressor section 22, ignited by fuel combustion in combustion chamber 23, expands in turbine section 24, and is then ejected from engine 2 through exhaust housing 25. Another portion of the airflow can flow through secondary flow path B, which takes the form of an elongated annular shape surrounding engine housing 21 and then exhaust housing 25. In this way, propulsion assembly 1 generates thrust. This thrust can, for example, be used for the benefit of the aircraft 100 to which propulsion assembly 1 is attached and fixed.
[0035] Exhaust housing For example in Figure 3 As shown, the exhaust housing 25 includes an inner ring 29 and an outer ring 30. The inner ring 29 includes an outer wall 290, and the outer ring 30 includes an inner wall 300. The outer wall 290 of the inner ring 29 and the inner wall 300 of the outer ring 30 define a main flow path A in the exhaust housing 25 extending from the engine housing 21 to the outlet of the engine 2.
[0036] The exhaust housing 25 includes arms (referred to as guide vanes 31) with aerodynamic profiles. Guide vanes 31 extend radially in the main flow path A of the inner ring 29 and preferably extend into the outer ring 30. Guide vanes 31 are circumferentially distributed around a longitudinal axis XX. For simplicity, the guide vanes 31 of the exhaust housing 25, and possibly the previously described guide vanes, are simply referred to as "vanes". Furthermore, the assembly formed by the inner ring, the vanes referred to as guide vanes, and possibly the outer ring, can generally be referred to as a guide vane assembly.
[0037] housing arm according to Figure 3 In one embodiment shown, each blade 31 extends radially and includes a base 32 and a tip 33 along its radial direction. The base 32 is connected to the inner ring 29. Advantageously, the tip 33 of the blade 31 is connected to the outer ring 30. Thus, the blade 31 includes a height h between the base 32 and the tip 33.
[0038] Each blade 31 includes a leading edge 34 and a trailing edge 35 in the direction of airflow. For example, in... Figure 4a As shown, the leading edge 34 is formed by the upstream point with the smallest radius of curvature on each section 36 of the blade 31 along a plane PP orthogonal to the radial extension direction of the blade 31. The trailing edge 35 is formed by the downstream point with the smallest radius of curvature on each section 36 of the blade 31.
[0039] The blade 31 includes an arched back wall 37 and an arched belly wall 38. The arched back wall 37 and the arched belly wall 38 extend from the base 32 to the tip 33 of the blade 31, from the leading edge 34 to the trailing edge 35, and on either side from the leading edge 34 to the trailing edge 35. Therefore, the arched back wall 37 and the arched belly wall 38 meet at the leading edge 34 and the trailing edge 35. The surface area of the arched back wall 37 is larger than the surface area of the arched belly wall 38.
[0040] Each section 36 of the blade 31 includes a leading edge point 340, a trailing edge point 350, a curved arched back line 370 connecting the leading edge point 340 and the trailing edge point 350, and a curved arched web line 380 that also connects the leading edge point 340 and the trailing edge point 350.
[0041] Leading edge point 340 is formed in section 36 by leading edge 34, and trailing edge point 350 is formed in section 36 by trailing edge 35. Arch back line 370 is formed in section 36 by arch back wall 37, and arch belly line 380 is formed in section 36 by arch belly wall 38. Arch back line 370 includes a curve length from leading edge point 340 to trailing edge point 350, which is greater than the curve length of arch belly line 380 from leading edge point 340 to trailing edge point 350.
[0042] The section 36 of the blade 31 also includes a centerline 39 and a main cross-section 40. The centerline 39 is a line that passes equidistantly from the arch back line 370 and the arch belly line 380, connecting the leading edge point 340 and the trailing edge point 350 on the section 36. The main cross-section 40 of the section 36 is the longest segment, perpendicular to the centerline 39, connecting the point on the arch back line 370 and the point on the arch belly line 380.
[0043] Because the blade 31 has a streamlined shape, the description of section 36 of the blade 31 applies to each section 36 of the blade 31 in the plane PP orthogonal to the radial extension direction of the blade 31. For simplicity, the “mid-plane M” and “main cross-section 40” of the blade 31 will be used below. The mid-plane M of the blade 31 is the surface formed by the centerline 39 of each section 36 of the blade 31, and the main cross-section 40 of the blade 31 is the surface formed by the main cross-section 40 of each section 36 of the blade 31.
[0044] In at least one section 36 (particularly the section shown in FIG4), the arch back line 370 is a convex line (between the leading edge 34 and the trailing edge 35), and the arch belly line 380 is another convex line (between the leading edge 34 and the trailing edge 35). "Convex line" means that in this section 36, both the arch belly wall and the arch back wall are convex, and therefore do not form grooves (like recessed walls).
[0045] This characteristic is preferably verified in each section 36 from the base 32 of the blade 31 to the tip 33 of the blade 31. Therefore, the arched back wall 37 and the arched belly wall 38 have opposing convexities relative to each other. This improves the airflow along the blade 31, regardless of the operating mode of the turbine 1.
[0046] slot in the arm Depending on the operating mode of engine 2, the airflow in the main flow path A can be altered. For example, the airflow in the main flow path A and therefore the angle of incidence relative to the rotor blade 31 can differ between takeoff mode and cruise mode.
[0047] Preferably, the impeller 31 of the exhaust housing 25 includes a slot 5, such as, for example, in Figure 4b As shown in the diagram, the slot 5 is configured to deflect a portion of the airflow flowing in the main path A and reaching the impeller 31, thereby preventing airflow separation downstream of the impeller 31, regardless of the operating mode of the engine 2.
[0048] Advantageously, each of the multiple blades 31 of the exhaust housing 25 includes a slot 5. Alternatively, some or all of the blades 31 of all arms and / or compressor section 22 and turbine section 24 of the exhaust housing 25 each include a slot 5.
[0049] For example in Figure 5As shown, the slot 5 of the blade 31 extends radially and uniformly from the base 32 of the blade 31 to the tip 33 of the blade 31. The slot 5 is a through slot; in other words, the slot 5 includes an inlet 51 and an outlet 52. The inlet 51 and the outlet 52 extend from the base 32 of the blade 31 to the tip 33 of the blade 31, respectively. Therefore, the slot 5 divides the blade 31 from the base 32 to the tip 33 into a main portion 310 including a trailing edge 35 and a secondary portion 311. Thus, the main portion 310 is located downstream of the secondary portion 311 relative to the slot 5.
[0050] The slot 5 includes a main wall 53 shared with the main portion 310 and a secondary wall 54 shared with the secondary portion 311. The main wall 53 and the secondary wall 54 may be contained in parallel planes or curved surfaces of the same or different shapes.
[0051] Inlet 51 opens onto the arched back wall 37 or arched belly wall 38 near the main cross-section 40, allowing a portion of the airflow reaching the impeller 31 to enter the slot 5. In other words, inlet 51 is formed in the impeller 31 on a portion of the arched back wall 37 or arched belly wall 38, and the normal vector of inlet 51 forms an angle greater than 90° with the direction vector of the second direction Y'. The second direction Y' is orthogonal to the main cross-section 40, and the direction vector is oriented in the direction of airflow. Advantageously, the distance between inlet 51 and the leading edge 34 represents + / - 10% of the curve length of the arched belly line 380 (in other words, the arched belly wall 38) from the leading edge 34 to the trailing edge 35.
[0052] Preferably, at the inlet 51 of the slot 5, the main wall 53 of the slot 5 has a first direction Y in a plane PP orthogonal to the radial extension direction of the blade 31, i.e., in the cross section 36 of the blade 31. The first direction Y forms an angle of 45° + / - 25° with respect to a second direction Y' orthogonal to the main cross section 40.
[0053] The outlet 52 leads downstream of the inlet 51 to the arched back wall 37 or arched belly wall 38 of the blade 31. Preferably, the outlet 52 leads to the arched back wall 37. Advantageously, the distance between the outlet 52 and the leading edge 34 is between 20% and 60% of the curve length of the arched belly line 380.
[0054] Preferably, at the outlet 52, the main wall 53 is tangentially continuous with the arched back wall 37 (in other words, with the arched back wall 37 of the main portion 310 of the blade 31).
[0055] The slot 5 has a width 55. The width 55 of the slot 5 is constant from the base 32 to the tip 33, but can vary within the slot 5 between the inlet 51 and the outlet 52. The width 55 of the slot 5 is defined by the diameter of the inscribed circle within the slot 5 (that is, each circle tangent to the main wall 53 and the secondary wall 54 on either side). Preferably, the width 55 at the outlet 52 is less than or equal to the width 55 at the inlet 51. The width 55 of the slot 5 at the outlet 52 is considered at the point of minimum radius of curvature downstream of the secondary wall 54. The width 55 of the slot 5 at the inlet 51 is considered at the point of minimum radius of curvature upstream of the secondary wall 54.
Claims
1. A turbine guide vane assembly (21, 25) through which airflow flows, the assembly (21, 25) comprising: -Inner ring (29) extending along longitudinal axis XX. - The outer ring (30) located radially outside the inner ring (29), and - Guide vane (31), the guide vane extending radially from the inner ring (29) to the outer ring (30) in the radial direction, the guide vane (31) includes a leading edge (34) and a trailing edge (35), the trailing edge being located downstream of the leading edge (34) in the airflow direction, and the guide vane including an arched back wall (37) and an arched belly wall (38) extending from the leading edge (34) to the trailing edge (35), the guide vane (31) having a cross section (36) in a transverse plane (PP) orthogonal to the radial direction, the arched back wall (37) and the arched belly wall (38) forming two convex lines in the cross section (36); The guide vane (31) also includes a through slot (5) which is at least partially formed in the arch back wall (37) and extends over the entire height of the guide vane (31).
2. The component according to claim 1, wherein, The slot (5) includes an inlet (51) and an outlet (52), the outlet (52) leading to the arched back wall (37) and being located downstream of the inlet (51) in the direction of airflow.
3. The component according to claim 2, wherein, The leading edge (34) is formed by the upstream point (340) with the smallest radius of curvature on each section (36) of the guide vane (31), and the trailing edge (35) is formed by the downstream point (350) with the smallest radius of curvature on each section (36) of the guide vane (31).
4. The component according to claim 3, wherein, The slot (5) divides the guide vane (31) into a main part (310) including the trailing edge (35) and a secondary part (311), wherein the slot (5) includes a main wall (53) shared with the main part (310) and a secondary wall (54) shared with the secondary part (311).
5. The component according to claim 4, wherein, At the entrance (51) of the slot (5), the main wall (53) of the slot (5) has a first direction (Y) in a plane (PP) orthogonal to the radial extension direction of the guide vane (31), the first direction forming an angle of 45°+ / -25° with respect to a second direction (Y') orthogonal to the main cross section (40) of the section (36) of the guide vane (31).
6. The component according to any one of claims 2 to 5, wherein, The distance between the entrance (51) and the leading edge (34) is + / - 10% of the curve length of the arched wall (38) from the leading edge (34) to the trailing edge (35).
7. The component according to any one of claims 2 to 6, wherein, At the outlet (52), the main wall (53) is tangentially continuous with the arched back wall (37) of the guide vane (31).
8. The component according to any one of claims 2 to 7, wherein, The distance between the outlet (52) and the leading edge (34) is between 20% and 60% of the curved distance of the arch back wall (37) from the leading edge (34) to the trailing edge (35).
9. The component according to any one of claims 2 to 8, wherein, The width (55) of the slot (5) is equal to the diameter of the inscribed circle in the slot (5), each inscribed circle being tangent to the main wall (53) and the secondary wall (54), wherein the width (55) of the outlet (52) is equal to or less than the width (55) of the inlet (51).
10. An assembly comprising a plurality of guide vanes (31), each guide vane comprising a slot (5) according to any one of claims 1 to 9.
11. An exhaust housing (25) comprising the components according to any one of claims 1 to 10.
12. A turbine (1) comprising an exhaust casing (25) according to claim 11.
13. An aircraft (100) comprising a turbine (1) according to claim 12.