Tail nozzle, aeroengine, and aircraft

Abstract

The present invention discloses a tail nozzle, an aeroengine, and an aircraft. The tail nozzle includes a plurality of segmented parts, and the segmented parts surround an exhaust port of the tail nozzle. The tail nozzle further includes a deformation inner ring made of a shape memory alloy. Wherein, there are slits between the segmented parts, the deformation inner ring is arranged inside the segmented parts, at least a part of the deformation inner ring coincides with the slits in the axial direction, and drives the segmented parts to move and change the spacing of the slits in a temperature deformation state, so as to change the size of the exhaust port of the tail nozzle. By using a shape memory alloy as an actuating mechanism, the nozzle area of the tail nozzle is changed at different temperatures, so as to effectively avoid the problem of noise without adding too much weight and complex mechanisms.

Description

Technical Field

[0001] The present invention relates to a tail nozzle, an aeroengine, and an aircraft. Background Art

[0002] When the tail nozzle of an aeroengine is working, it has different working states. By changing the size of the outlet of the tail nozzle, the working state of the engine can be changed, enabling the engine to obtain good performance in various working states. However, the tail nozzle with adjustable nozzles is usually of a mechanical structure, which is complex in construction, heavy in weight, and the mechanical transmission components work unreliably at high temperatures. Therefore, a non-adjustable convergent tail nozzle is adopted for civil turbofan engines.

[0003] Currently, large bypass ratio turbofan engines usually adopt a non-adjustable convergent tail nozzle, also known as a subsonic nozzle with a fixed nozzle, including a serrated tail nozzle with noise reduction function. Its structure is the simplest and the weight is the lightest. Almost all civil turbofan engines such as CFM56, PW4000, RB211, and GE90 adopt this kind of tail nozzle. Although when the available pressure ratio of the nozzle is greater than the critical pressure ratio (1.85), the gas cannot be fully expanded in the convergent tail nozzle, but in the case of a relatively low flight speed (Ma≤1.5), the energy loss of the gas due to incomplete expansion is small. Therefore, it is appropriate to adopt this simple convergent tail nozzle.

[0004] However, in addition to the energy loss caused by incomplete expansion of the gas (resulting in a decrease in engine efficiency), with the increasing requirements for the environmental indicators of aeroengines, the noise problem caused by different jet velocities at different engine working state points has become increasingly prominent. Although a serrated noise reduction tail nozzle has been designed, the noise problem still exists at non-working state points of the engine, such as maximum climb. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defect that in the prior art, an aeroengine cannot avoid a large noise at different working states while ensuring a simple structure and a light weight, and to provide a tail nozzle, an aeroengine, and an aircraft.

[0006] The present invention solves the above technical problem by the following technical solutions:

[0007] A tail nozzle, used for an aircraft engine, comprises a plurality of slice parts, wherein the slice parts are arranged to form an exhaust port of the tail nozzle, and is characterized in that the tail nozzle also comprises a deformable inner ring made of a shape memory alloy, wherein slits are provided between the slice parts, and the deformable inner ring is arranged on the inner side of the slice parts, and at least a portion of the deformable inner ring coincides with the slits in the axial direction, and drives the slice parts to move and change the spacing of the slits in a temperature-deformed state, thereby changing the size of the exhaust port of the tail nozzle.

[0008] Using shape memory alloy as the actuating mechanism to control the nozzle area of the tail nozzle can effectively avoid the noise problem without adding too much weight and complex mechanism. The deformed inner ring can match the corresponding working state by setting the phase change temperature. When the exhaust of the tail nozzle reaches the phase change temperature, it will deform, so that the exhaust port of the tail nozzle reaches the preset size, effectively reducing noise.

[0009] At the same time, the slit achieves a greater change in the size of the exhaust port. The deformed inner ring located on the inner side of the slice blocks the inner side of the slit. When the slit is stretched, it can still be sealed on the inner side to prevent gas leakage from the slit. On the other hand, the deformed inner ring acts on the inner side of the slice, and can expand evenly from the inside. This avoids bulging when the deformed inner ring acts on the outer side of the slice, and avoids movement disconnection between the deformed inner ring and the slice.

[0010] Preferably, the shape of the slit is a straight line, an S-shaped slit, a zigzag shape, or a combination of the above.

[0011] Preferably, the shape of the slice portion is a sawtooth shape, an arc shape, a trapezoidal shape, or a combination of more.

[0012] Preferably, the deformable inner ring is a circumferentially continuous structure, and the deformable inner ring completely blocks the inner side of each of the slits in the circumferential direction.

[0013] Preferably, the shape of the deformed inner ring is a cylindrical structure with uniform wall thickness, a corrugated plate, a spring, or a combination of multiple thereof.

[0014] Preferably, an embedding groove is formed on the inner side of each of the segment parts, and each of the embedding grooves forms an embedding ring along the circumferential direction. The deformed inner ring is cylindrical and embedded in the embedding ring.

[0015] Preferably, the deformed inner ring has different circumferential dimensions at a plurality of different temperatures, and the segmented portions are expanded to different positions at different temperatures, so that the exhaust port of the tail nozzle is changed to a plurality of different dimensions.

[0016] Preferably, the deformed inner ring realizes deformation of different circumferential dimensions at multiple different temperatures through a combination of materials with different phase change points.

[0017] Preferably, the deformed inner ring is provided with at least two deformation segments, and at least two of the deformation segments have different phase change temperatures. Thus, for the engine in three states of idle, climb, and cruise, the exhaust nozzle has different exhaust temperatures in these three states. Through the contraction or expansion of the deformed inner ring at different temperatures, the opening or closing of the exhaust nozzle is realized.

[0018] Preferably, the deformation segments are distributed along the circumference of the deformed inner ring, and among them, the deformation segments with the same phase change temperature are evenly distributed at various positions of the deformed inner ring along the circumference.

[0019] Preferably, the deformed inner ring is made by additive manufacturing.

[0020] Preferably, the deformed inner ring is provided with at least two deformation segments with different phase change temperatures, and the deformation segments with different phase change temperatures are processed from the same shape memory alloy by using different additive manufacturing process parameters.

[0021] Preferably, the additive manufacturing process parameters are one or more of laser power, scanning rate, and scanning spacing, and / or the shape memory alloy is a nickel-titanium alloy.

[0022] Preferably, between the deformation segments with different phase change temperatures are formed by laser scanning along the circumference in sequence, and the material crystal phases between adjacent deformation segments with different phase change temperatures transition smoothly. Since it is made of the same shape memory alloy, the deformation segments of the deformed inner ring still form an integral body, and through laser scanning, when scanning a deformation segment, the adjacent deformation segments will also be heated, making the crystal phases between the deformation segments change slowly. Therefore, stress concentration will not occur at the junction between the deformation segments, ensuring the strength of the deformed inner ring during repeated deformation.

[0023] An aeroengine, characterized in that the aeroengine includes the exhaust nozzle, and among them, the exhaust nozzle is the core nozzle and / or the bypass nozzle of the aeroengine.

[0024] An aircraft, characterized in that the aircraft includes the aeroengine.

[0025] The positive and progressive effects of the present invention are as follows: Using a shape memory alloy as the actuating mechanism to change the control of the exhaust nozzle area at different temperatures, thereby effectively avoiding the problem of noise without adding too much weight and complex mechanisms. Description of the Drawings

[0026] Figure 1Schematic structural diagram of an aeroengine according to a preferred embodiment of the present invention.

[0027] Figure 2 Schematic structural diagram of a tail nozzle according to a preferred embodiment of the present invention.

[0028] Figure 3 Schematic structural diagram of a segmented part according to a preferred embodiment of the present invention.

[0029] Figure 4 is Figure 2 Schematic diagram of the initial state cross-sectional structure in the A-A direction in

[0030] Figure 5 is Figure 2 Schematic diagram of the cross-sectional structure in the A-A direction at a first working state in

[0031] Figure 6 is Figure 2 Schematic diagram of the cross-sectional structure in the A-A direction at a second working state in

[0032] Figure 7 Schematic diagram of the arrangement of a deformation section of a deformed inner ring according to a preferred embodiment of the present invention.

[0033] Figure 8 Another schematic diagram of the arrangement of a deformation section of a deformed inner ring according to a preferred embodiment of the present invention. Detailed implementation manners

[0034] The present invention will be further described below by way of examples, but the present invention is not limited to the scope of the described examples.

[0035] As Figure 1 shown, this embodiment discloses an aeroengine, which is mainly used for an aircraft. The aircraft may include one or more aeroengines of this embodiment. Among them, as Figure 1 shown, this embodiment exemplarily shows a specific structure of an aeroengine, including an engine nacelle 1, an outer bypass nozzle 2, an inner bypass nozzle 3, an inner bypass duct 4, and an outer bypass duct 5. Among them, the tail nozzle 6 of this embodiment can be used for the inner bypass nozzle 3 and / or the outer bypass nozzle 2 of the aeroengine. In aeroengines with other structures, the tail nozzle 6 can also be applied to the corresponding nozzle structures.

[0036] As Figures 2 - 3As shown in the figure, the exhaust nozzle 6 of this embodiment includes a number of segmented parts 61. The segmented parts 61 surround the exhaust port of the exhaust nozzle 6. The exhaust nozzle 6 further includes a deformation inner ring 62 made of shape memory alloy. Among them, there are slits 63 between the segmented parts 61. The deformation inner ring 62 is arranged inside the segmented parts 61. At least a part of the deformation inner ring 62 coincides with the slit 63 in the axial direction, and drives the segmented parts 61 to move and change the spacing of the slit 63 in the temperature deformation state, so as to change the size of the exhaust port of the exhaust nozzle 6.

[0037] Using shape memory alloy as the actuating mechanism to control the nozzle area of the exhaust nozzle 6 can effectively avoid the problem of noise without adding too much weight and complex mechanisms. By setting the phase change temperature, the deformation inner ring 62 can match the corresponding working state. When the exhaust of the exhaust nozzle 6 reaches the phase change temperature, it will deform, so that the exhaust port of the exhaust nozzle 6 reaches the preset size, effectively reducing noise.

[0038] At the same time, the slit 63 enables a larger change in the size of the exhaust port. The deformation inner ring 62 located inside the segmented part 61 seals the inside of the slit 63 on the one hand. When the slit 63 is expanded, it can still be sealed inside to prevent gas from leaking from the slit 63. On the other hand, the deformation inner ring 62 acts on the inner side of the segmented part 61 and can expand evenly from the inner side. It avoids the bulging phenomenon when the deformation inner ring 62 acts on the outer side of the segmented part 61, and avoids the movement disconnection between the deformation inner ring 62 and the segmented part 61.

[0039] Among them, the shape memory alloy referred to in this embodiment can be nickel-titanium alloy, or can include but not be limited to copper-nickel alloy, copper-aluminum alloy, copper-zinc alloy. In other embodiments, it can also be other known shape memory alloy materials. In the description of this embodiment, the axial direction and the circumferential direction respectively refer to the axial direction and the circumferential direction of the exhaust nozzle 6.

[0040] In this embodiment, the amount of size change of the shape memory alloy can be obtained by numerical simulation methods based on, but not limited to, the deformation coefficient of the shape memory alloy. For example, the pneumatic-noise coupling multidisciplinary multi-condition optimization method can be used. By according to different working state points, such as the relationship between the noise, aerodynamic performance and the size of the exhaust port 60 during engine takeoff, cruise, and landing, the optimal exhaust port size for each state can be obtained, so as to determine the size change of the shape memory alloy. Thus, while comprehensively improving the aerodynamic performance at different working state points, the noise level is always kept within the range of airworthiness requirements, reducing the air resistance of the exhaust nozzle at different working states of engine takeoff, cruise, and landing and the aerodynamic interference resistance between the engine and the aircraft.

[0041] In a preferred embodiment, the structural design of the tail nozzle 6 is applied to the internal nozzle. Due to the high exhaust temperature, thermal insulation measures can be further designed, such as by coating a thermal insulation ceramic coating on the inner side of the tail nozzle 6, or by additive manufacturing of shape memory alloy powder element control, such as using a formula of 25% Ni, 25% Pd, 16.6% Ti, 16.7% Hf, and 16.6% Zf by mass, which can increase the phase change temperature to 700°C-800°C.

[0042] In this embodiment, the shape of the slit 63 is a straight line, an S-shaped slit, a zigzag shape, or a combination of multiple shapes. The shape of the slice portion 61 is a zigzag shape, an arc shape, a trapezoid, or a combination of multiple shapes. Of course, in other embodiments, the slice portion and the slit may also be of other shapes.

[0043] In a preferred embodiment, the deformable inner ring 62 is a circumferentially continuous structure, and the deformable inner ring 62 completely blocks the inner side of each slit 63 in the circumferential direction. Thus, the gas can be blocked from leaking from the slit 63 in the circumferential direction. At the same time, the continuous structure can also achieve overall deformation and increase the deformation force. In a further preferred embodiment, the shape of the deformable inner ring 62 is a cylindrical structure with uniform wall thickness, a corrugated plate, a spring, or a combination of multiple thereof.

[0044] like Figure 3 As shown, in a preferred embodiment, an embedding groove 611 is formed on the inner side of each segment portion 61, and each embedding groove 611 forms an embedding ring along the circumferential direction. The deformed inner ring 62 is cylindrical and embedded in the embedding ring.

[0045] like Figure 4 , Figure 5 and Figure 6 As shown, in a preferred embodiment, the deformed inner ring 62 has different circumferential dimensions at multiple different temperatures, and the segmented portion 61 is expanded to different positions at different temperatures, so that the exhaust port of the tail nozzle 6 is changed to multiple different sizes.

[0046] In a further preferred embodiment, the deformable inner ring 62 is formed by a combination of materials with different phase transition points to achieve deformation of different circumferential dimensions at multiple different temperatures. In a more preferred embodiment, the deformable inner ring 62 is provided with at least two deformation segments, and at least two deformation segments have different phase transition temperatures. Thus, for the three states of the engine at slow speed, climbing, and cruising, the tail nozzle 6 has different exhaust temperatures in these three states, and the expansion or closing of the tail nozzle 6 is achieved by contracting or expanding the deformable inner ring 62 at different temperatures.

[0047] Among them, in a further preferred embodiment, the deformation sections are distributed circumferentially along the inner deformation ring 62, and the deformation sections having the same phase transition temperature are evenly distributed circumferentially at various positions of the inner deformation ring 62. As Figure 7 The inner deformation ring 62 shown is provided with two deformation sections a and b, and the two deformation sections a and b are arranged around the inner deformation ring 62 for one week. As Figure 7 The inner deformation ring 62 shown is provided with three deformation sections a, b and c, and the three deformation sections a, b and c are arranged around the inner deformation ring 62 for one week.

[0048] In a further preferred embodiment, the inner deformation ring 62 is made by additive manufacturing. The inner deformation ring 62 is provided with at least two deformation sections having different phase transition temperatures, and the deformation sections having different phase transition temperatures are processed from the same shape memory alloy by using different additive manufacturing process parameters.

[0049] In a preferred embodiment, the additive manufacturing process parameters can be one or more of laser power, scanning rate and scanning spacing. Through the tests of different specimens formed by changing the laser power resulting in the change of laser energy density, changing the scanning rate resulting in the change of laser energy density and changing the scanning spacing resulting in the change of laser energy density, it can be known that the phase transition temperature generally increases with the increase of the laser energy density used for forming.

[0050] Therefore, in the preferred embodiment, by adjusting one or more of the laser power, scanning rate and scanning spacing, different laser energy densities can be obtained, and by using different laser energy densities to form each deformation section in the deformation unit, each deformation section can have different phase transition temperatures. Among them, it can be determined by the way of multiple trials and errors the laser energy density adopted for each target phase transition temperature.

[0051] To verify that multiple deformation segments can achieve multiple deformations, different scanning rates can be used to form each deformation segment in the deformation unit, so that each deformation segment has a different phase transition temperature. A nickel-titanium alloy (NiTi) structure with multi-action characteristics prepared by selective laser melting. When preparing this structure, different laser scanning speeds (400, 500, 800 mm / s respectively) are selected for different parts, but the laser power (120 W), scanning spacing (80 μm), and powder layer thickness (30 μm) are kept unchanged. The main difference between the three circular structures lies in the different regions corresponding to different laser scanning speeds (for example, one is 400, 500, 800 mm / s clockwise, another is 500, 400, 800 mm / s clockwise, and the last one is 800, 500, 400 mm / s clockwise), that is, the arrangement and combination of the NiTi parts prepared at different scanning speeds are different. After deforming these three circles and putting them into a water bath, as the temperature rises, the shapes gradually recover, indicating that they all have multi-action deformation characteristics.

[0052] In a preferred embodiment, the deformation segments with different phase transition temperatures are sequentially scanned by a laser along the circumferential direction of the deformation inner ring 62, and the material crystal phases between adjacent deformation segments with different phase transition temperatures transition smoothly. Since the same shape memory alloy is used, the deformation segments of the deformation inner ring 62 still form a whole. And through laser scanning, when scanning a deformation segment, the adjacent deformation segments will also be heated, so that the crystal phases between the deformation segments change slowly. Therefore, stress concentration will not occur at the junction of the deformation segments, ensuring the strength of the deformation inner ring 62 during repeated deformation.

[0053] The present invention uses a shape memory alloy as an actuating mechanism to change the control nozzle area of the tail nozzle at different temperatures, thereby effectively avoiding the problem of noise without adding too much weight and complex mechanisms.

[0054] Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that this is only for illustration. The protection scope of the present invention is defined by the appended claims. Without departing from the principles and essence of the present invention, those skilled in the art can make various changes or modifications to these embodiments, but these changes and modifications all fall within the protection scope of the present invention.

Claims

1. A nozzle, for an aeroengine, comprising a plurality of segmented parts, the segmented parts surrounding an exhaust port of the nozzle, characterized in that, The tail nozzle also includes a deformable inner ring made of shape memory alloy, wherein the slice portion has a first part and a second part distributed along the axial direction, a slit is provided between the first parts, and a tooth-shaped notch is provided between the second parts; the deformable inner ring is arranged on the inner side of the slice portion, at least a part of the deformable inner ring overlaps with the slit in the axial direction to seal the slit of the overlapping part, and drives the slice portion to move and change the spacing of the slits in the temperature deformation state, thereby changing the size of the exhaust port of the tail nozzle, and when the slit is stretched open, the deformable inner ring seals the inner side to prevent gas leakage from the slit.

2. The exhaust nozzle according to claim 1, characterized in that, The shape of the slit is one of a straight line, an S-shaped slit, and a zigzag shape, or a combination of the two or more.

3. The tailpipe according to claim 1, characterized in that, The shape of the slice portion is one or a combination of the following: a sawtooth shape, an arc shape, and a trapezoid shape.

4. The exhaust nozzle according to claim 1, characterized in that, The deformable inner ring is a circumferentially continuous structure, and the deformable inner ring completely blocks the inner side of each of the slits in the circumferential direction.

5. The exhaust nozzle according to claim 1, characterized in that, The shape of the deformed inner ring is one or a combination of a cylindrical structure with uniform wall thickness, a corrugated plate, and a spring.

6. The tail nozzle according to claim 1, characterized in that, An embedding groove is formed on the inner side of each of the segment parts, and each of the embedding grooves forms an embedding ring along the circumferential direction. The deformed inner ring is cylindrical and embedded in the embedding ring.

7. The exhaust nozzle according to claim 1, characterized in that The deformed inner ring has different circumferential dimensions at a plurality of different temperatures, and the segmented portions are expanded to different positions at different temperatures, so that the exhaust port of the tail nozzle is changed into a plurality of different dimensions.

8. The exhaust nozzle according to claim 7, characterized in that, The deformable inner ring is formed by combining materials with different phase change points to achieve deformation of different circumferential dimensions at multiple different temperatures.

9. The exhaust nozzle according to claim 8, characterized in that, The deformable inner ring is provided with at least two deformation sections, and at least two of the deformation sections have different phase change temperatures.

10. The exhaust nozzle according to claim 9, characterized in that, The deformation segments are distributed along the circumference of the deformation inner ring, wherein the deformation segments having the same phase change temperature are evenly distributed at various positions of the deformation inner ring along the circumference.

11. The exhaust nozzle according to any one of claims 1-10, characterized in that, The deformable inner ring is manufactured by additive manufacturing.

12. The nozzle according to claim 11, characterized in that, The deformable inner ring is provided with at least two deformation segments with different phase change temperatures, and the deformation segments with different phase change temperatures are formed by processing the same shape memory alloy using different additive manufacturing process parameters.

13. The exhaust nozzle according to claim 12, characterized in that, The additive manufacturing process parameters are one or more parameters of laser power, scanning rate and scanning spacing, and / or the shape memory alloy is nickel-titanium alloy.

14. The exhaust nozzle according to claim 12, characterized in that, The deformation segments with different phase change temperatures are formed by sequentially scanning the laser along the circumferential direction, and the material crystal phases between adjacent deformation segments with different phase change temperatures transition smoothly.

15. An aeroengine, characterized in that, The aircraft engine comprises the tail nozzle as described in any one of claims 1 to 14, wherein the tail nozzle is an internal nozzle and / or an external nozzle of the aircraft engine.

16. An aircraft, characterized in that, The aircraft comprises one or more aircraft engines according to claim 15 .

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