Additive manufacturing tail nozzle manufacturing method and tail nozzle structure

Abstract

This invention relates to the field of additive manufacturing technology for aero-engines, and discloses a method for manufacturing an additively manufactured exhaust nozzle and its structure. The method includes: performing topology optimization with the overall rigidity of the exhaust nozzle as the target to obtain a density cloud map of the exhaust nozzle; obtaining a schematic diagram of the location of reinforcing ribs based on the density cloud map; generating a vibration stress map through random vibration analysis of the exhaust nozzle; geometrically reconstructing the exhaust nozzle structure diagram by combining the schematic diagram of the reinforcing rib locations and the vibration stress map; and manufacturing the exhaust nozzle according to the structure diagram. Under the same weight, the reinforcing ribs improve the overall structural rigidity of the exhaust nozzle, resulting in a smaller sway amplitude and reduced lateral displacement of the exhaust nozzle exit section under service conditions. With the same clearance as the helicopter exhaust pipe, the exhaust nozzle is less likely to scrape against the helicopter exhaust pipe. The additive manufacturing method for exhaust nozzles provided by this invention solves the problem of insufficient overall rigidity of exhaust nozzles in the prior art.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology for aero-engines, specifically to a method for manufacturing an additive manufacturing nozzle and a nozzle structure. Background Technology

[0002] The tail nozzle of an aircraft engine is an important component of the exhaust system of a turbojet engine. The main function of the tail nozzle is to allow the gas after the turbine to continue to expand, fully converting the remaining enthalpy in the gas into kinetic energy, so that the gas is ejected from the nozzle at high speed to generate thrust.

[0003] In the prior art, the tail nozzle structure is usually a cylindrical thin-walled structure, which is formed by integral welding, the mounting edge is formed by machining, the flow channel wall is formed by welding sheet metal, and the wall thickness of the flow channel wall is designed to be uniform.

[0004] However, in service environments, the airflow excitation inside the tail nozzle is quite complex. The overall thin-walled structure of the tail nozzle results in insufficient overall rigidity and significant oscillation at the exit section, affecting the overlap gap between the helicopter exhaust pipe and the engine tail nozzle, which can easily lead to scraping and abrasion with the helicopter exhaust pipe. Summary of the Invention

[0005] This invention provides an additive manufacturing method for tail nozzles and a tail nozzle structure to solve the problem of insufficient overall rigidity of tail nozzles in the prior art.

[0006] In a first aspect, the present invention provides an additive manufacturing method for a tail nozzle, comprising the following steps: performing topology optimization with the overall rigidity of the tail nozzle as the target to obtain a density cloud map of the tail nozzle, and obtaining a schematic diagram of the position of the reinforcing ribs based on the density cloud map; generating a vibration stress map through random vibration analysis of the tail nozzle; performing geometric reconstruction by combining the schematic diagram of the position of the reinforcing ribs and the vibration stress map to obtain a tail nozzle structure diagram; and processing and generating the tail nozzle according to the tail nozzle structure diagram.

[0007] Beneficial Effects: Aiming for overall nozzle rigidity, topology optimization determines the location of reinforcing ribs. Combined with the location of vibration stress hazard zones, geometric reconstruction yields the nozzle structure. Under the same nozzle weight, the reinforcing ribs improve overall structural rigidity, resulting in smaller sway amplitude and reduced lateral displacement of the nozzle exit section under service conditions. With the same clearance as the helicopter exhaust pipe, the nozzle is less prone to scraping against the helicopter exhaust pipe. The additive manufacturing method for nozzles provided by this invention solves the problem of insufficient overall nozzle rigidity in existing technologies.

[0008] In one alternative implementation, when generating the vibration stress map, areas with high vibration stress are obtained through random vibration analysis or tailpipe dynamic stress measurement, high-cycle fatigue risk areas are identified, and these areas are locally thickened.

[0009] Beneficial effects: By thickening the high-cycle fatigue risk area, the resistance to high-cycle fatigue can be improved, and high-cycle fatigue cracks are less likely to occur.

[0010] In one alternative implementation, the tailpipe is locally thickened near the inlet and outlet.

[0011] Beneficial effects: By thickening the inlet and outlet of the tail nozzle, the strength of the installation edges at the inlet and outlet can be guaranteed.

[0012] In one alternative implementation, the tail nozzle is formed by additive manufacturing.

[0013] Beneficial effects: Additive manufacturing uses a method of gradually accumulating materials to create solid parts, which is easier to form than sheet metal processing.

[0014] Secondly, the present invention also provides a tail nozzle structure, which is manufactured using the additive manufacturing tail nozzle manufacturing method described in the above embodiments, comprising: a pipe body and reinforcing ribs, wherein the pipe body is configured as a cylindrical structure; and multiple reinforcing ribs are provided on the outer wall surface of the pipe body.

[0015] Beneficial effects: Since the additive manufacturing tail nozzle manufacturing method described in the above embodiments is used for processing and shaping, it has any of the above advantages.

[0016] In one optional embodiment, the reinforcing rib includes at least a first reinforcing portion covering the area of ​​the pipe body with large vibration stress; the pipe body has an inlet and an outlet, and both the inlet and outlet of the pipe body are provided with mounting edges, and a second reinforcing portion is provided on the portion of the pipe body near the mounting edges, the second reinforcing portion being connected to the first reinforcing portion.

[0017] Beneficial effects: The second reinforcing part can ensure the strength of the inlet and outlet mounting edges. At the same time, the connection between the first and second reinforcing parts forms a stable reinforcing rib, which improves the overall structural strength of the tail nozzle.

[0018] In one optional embodiment, the reinforcing rib further includes: a support arm, the support arm connecting the first reinforcing portion and the second reinforcing portion, and / or, the support arm connecting an adjacent first reinforcing portion; the thickness of the support arm is less than the thickness of the first reinforcing portion and / or the second reinforcing portion.

[0019] Beneficial effects: By connecting multiple first and second reinforcing parts with the support arm, a stable reinforcing rib structure is formed, which improves the overall structural strength of the tail nozzle. At the same time, the first and second reinforcing parts are locally thickened compared to the support arm, which can improve the resistance to high cycle fatigue, ensure the strength of the inlet and outlet mounting edges, and achieve lightweight design.

[0020] In one alternative implementation, the widths of the support arms are equal along the extending direction of the support arms.

[0021] Beneficial effect: Support arms with equal width along the extension direction can distribute stress evenly.

[0022] In one alternative embodiment, the reinforcing rib is further provided with a weight-reducing block.

[0023] Beneficial effects: By using weight-reducing blocks, a lightweight and high-rigidity design can be achieved while ensuring overall strength.

[0024] In one alternative embodiment, the reinforcing ribs are symmetrically arranged on the outer wall surface of the tube.

[0025] Beneficial effects: By symmetrically setting reinforcing ribs on the outer wall of the tube, the uniformity of stress on the tube can be improved, which is conducive to improving the overall structural strength. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of a tailpipe structure according to an embodiment of the present invention; Figure 2 for Figure 1 A second-view schematic diagram of the tail nozzle structure shown; Figure 3 for Figure 1 A third-view schematic diagram of the tail nozzle structure shown; Figure 4 for Figure 1 Density cloud map of the tail nozzle structure from a first-view perspective; Figure 5 for Figure 1 Density cloud map of the tail nozzle structure from a second-view perspective; Figure 6 According to Figure 4 A schematic diagram showing the location of the reinforcing ribs; Figure 7 According to Figure 5 A schematic diagram showing the location of the reinforcing ribs; Figure 8 for Figure 1 Vibration stress diagram of the tail nozzle structure from a first-view perspective; Figure 9 for Figure 1 Vibration stress diagram of the tail nozzle structure from a second perspective; Figure 10 for Figure 1 Vibration stress diagram of the tail nozzle structure from a third-angle perspective; Figure 11 for Figure 1 The diagram shows the vibration stress of the tail nozzle structure from a fourth-angle perspective.

[0028] Explanation of reference numerals in the attached figures: 1. Pipe body; 2. Mounting edge; 3. First reinforcing part; 4. Second reinforcing part; 5. Support arm; 6. Weight reduction block. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] In related technologies, the tail nozzle uses a single thin-walled structure, resulting in insufficient overall rigidity. Under service conditions, the exit section exhibits significant sway, affecting the overlap gap between the helicopter exhaust pipe and the engine tail nozzle, and easily leading to scraping against the helicopter exhaust pipe. Simultaneously, due to the complex airflow excitation inside the tail nozzle under service conditions, high-cycle fatigue cracks caused by random vibrations are prone to occur in the exit section. Increasing the overall wall thickness would, on the one hand, cause the tail nozzle to become excessively heavy, and on the other hand, the overall increase in rigidity would not be effective.

[0031] The following is combined Figures 1 to 11 The following describes embodiments of the present invention.

[0032] According to an embodiment of the present invention, in one aspect, an additive manufacturing method for a tail nozzle is provided, comprising the following steps: performing topology optimization with the overall rigidity of the tail nozzle as the target to obtain a density cloud map of the tail nozzle; obtaining a schematic diagram of the position of the reinforcing ribs based on the density cloud map; generating a vibration stress map; combining the schematic diagram of the position of the reinforcing ribs and the vibration stress map to perform geometric reconstruction to obtain a tail nozzle structure diagram; and processing and generating the tail nozzle based on the tail nozzle structure diagram.

[0033] In use, with the overall rigidity of the nozzle as the target, topology optimization is used to determine the location of the reinforcing ribs. Combined with the location of the vibration stress danger zone, the nozzle structure is obtained through geometric reconstruction. Under the same weight of the nozzle, the reinforcing ribs can improve the overall structural rigidity, resulting in a smaller sway amplitude and reduced lateral displacement of the nozzle exit section under service conditions. Under the same clearance as the helicopter exhaust pipe, the nozzle is less likely to scrape against the helicopter exhaust pipe. The additive manufacturing nozzle fabrication method provided in this embodiment solves the problem of insufficient overall rigidity of the nozzle in the prior art.

[0034] Specifically, such as Figure 4 The density cloud map shown has a density threshold ranging from 0 to 1. The larger the value, the greater the impact on the stiffness of the tail nozzle.

[0035] In one embodiment, when generating the vibration stress map, areas with high vibration stress are identified through random vibration analysis or dynamic stress measurement of the nozzle, and high-cycle fatigue hazard areas are identified. These areas are then locally thickened. By thickening the high-cycle fatigue hazard areas, resistance to high-cycle fatigue can be improved, and the formation of high-cycle fatigue cracks is less likely. Alternatively, as an alternative implementation, the high-cycle fatigue hazard areas of the nozzle are set to the same thickness as other areas of the reinforcing ribs.

[0036] Specifically, such as Figure 6 The vibration stress diagram shown in the figure indicates the high-cycle fatigue risk area marked in red.

[0037] In one embodiment, the nozzle is locally thickened near the inlet and outlet. This thickening at the nozzle inlet and outlet ensures the strength of the mounting edges 2. Alternatively, as an alternative implementation, the nozzle inlet and outlet can be of the same thickness as other areas of the reinforcing rib.

[0038] In one embodiment, the exhaust nozzle is formed using additive manufacturing. Additive manufacturing uses a method of gradually accumulating material to create solid parts, which is easier to form than sheet metal processing. Alternatively, as an alternative implementation, the exhaust nozzle can also be formed using sheet metal processing.

[0039] According to an embodiment of the present invention, another aspect provides a tailpipe structure, manufactured using the additive manufacturing tailpipe method described in the above embodiments, comprising: a pipe body 1 and reinforcing ribs, wherein the pipe body 1 is configured as a cylindrical structure; and multiple reinforcing ribs are provided on the outer wall surface of the pipe body 1. The reinforcing ribs at least cover areas with high vibration stress, and the overall strength of the pipe body 1 is improved by the multiple reinforcing ribs.

[0040] Specifically, the outer contour of the reinforcing rib is irregular in shape.

[0041] In one embodiment, the reinforcing rib includes at least a first reinforcing portion 3 covering the area of ​​the pipe body 1 where vibration stress is high; the pipe body 1 has an inlet and an outlet, and mounting edges 2 are provided at both the inlet and outlet of the pipe body 1. A second reinforcing portion 4 is provided on the portion of the pipe body 1 near the mounting edges 2, and the second reinforcing portion 4 is connected to the first reinforcing portion 3. The second reinforcing portion 4 ensures the strength of the inlet and outlet mounting edges 2. At the same time, the connection between the first reinforcing portion 3 and the second reinforcing portion 4 forms a stable reinforcing rib, improving the overall structural strength of the tailpipe.

[0042] In one embodiment, the reinforcing rib further includes a support arm 5, which connects the first reinforcing part 3 and the second reinforcing part 4, and / or connects adjacent first reinforcing parts 3; the thickness of the support arm 5 is less than the thickness of the first reinforcing part 3 and / or the second reinforcing part 4. By connecting multiple first reinforcing parts 3 and second reinforcing parts 4 through the support arm 5, a stable reinforcing rib is formed, improving the overall structural strength of the tailpipe. Simultaneously, the first reinforcing parts 3 and second reinforcing parts 4 are locally thicker than the support arm 5, which improves resistance to high-cycle fatigue, ensures the strength of the inlet and outlet mounting edges 2, and achieves a lightweight design. Alternatively, as an alternative embodiment, the first reinforcing parts 3 and second reinforcing parts 4 have the same thickness as the support arm 5.

[0043] In one embodiment, the support arm 5 has a uniform width along its extension direction. This uniform width along the extension direction allows for even stress distribution. Alternatively, as an alternative implementation, the support arm 5 can be configured with different widths depending on the rigidity requirements of the nozzle.

[0044] Specifically, the extension lengths of the multiple support arms 5 are different.

[0045] In one embodiment, the reinforcing rib is further provided with a weight-reducing block 6. The weight-reducing block 6 allows for a lightweight, high-rigidity design while maintaining overall strength. Alternatively, as an alternative implementation, the weight-reducing block 6 can be omitted, and the reinforcing rib can be configured as a continuous, integral structure.

[0046] Specifically, the weight reduction block 6 can be set as a circle, triangle, trapezoid or other shape.

[0047] In one embodiment, the reinforcing ribs are symmetrically arranged on the outer wall surface of the pipe body 1. By symmetrically arranging the reinforcing ribs on the outer wall surface of the pipe body 1, the uniformity of the force on the pipe body 1 can be improved, which is beneficial to improving the overall structural strength.

[0048] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended invention.

Claims

1. A method of additive manufacturing of a tail nozzle, characterized in that, Includes the following steps: Topology optimization is performed with the overall rigidity of the tail nozzle as the target, and the density cloud map of the tail nozzle is obtained. Based on the density cloud map, a schematic diagram of the location of the reinforcing ribs is obtained. Vibration stress diagrams are generated through random vibration analysis of the tail nozzle; By combining the schematic diagram of the stiffener location and the vibration stress diagram, a geometric reconstruction is performed to obtain the tail nozzle structure diagram; It is manufactured based on the tail nozzle structure diagram.

2. The additive manufacturing exhaust nozzle fabrication method of claim 1, wherein, When generating vibration stress maps, areas with high vibration stress are identified through random vibration analysis or dynamic stress measurement of the tail nozzle, and high-cycle fatigue risk areas are identified. These areas are then locally thickened.

3. The additive manufacturing exhaust nozzle fabrication method of claim 1, wherein, The tail nozzle is locally thickened near the inlet and outlet.

4. The additive manufacturing exhaust nozzle fabrication method of any of claims 1-3, wherein, The tail nozzle is formed by additive manufacturing.

5. A nozzle structure made by the method of claim 1-4, wherein, include: The tube body (1) is configured as a cylindrical structure; Multiple reinforcing ribs are provided on the outer wall surface of the tube body (1).

6. The tail nozzle structure of claim 5, wherein The reinforcing rib includes at least a first reinforcing part (3) covering the high-cycle fatigue danger area of ​​the tube body (1); The pipe body (1) has an inlet and an outlet. Both the inlet and outlet of the pipe body (1) are provided with an installation edge (2). The portion of the pipe body (1) near the installation edge (2) is provided with a second reinforcing part (4). The second reinforcing part (4) is connected to the first reinforcing part (3).

7. The tail nozzle structure of claim 6, wherein The reinforcing rib further includes: a support arm (5), which connects the first reinforcing part (3) and the second reinforcing part (4), and / or, the support arm (5) connects the adjacent first reinforcing part (3). The thickness of the support arm (5) is less than the thickness of the first reinforcing part (3) and / or the second reinforcing part (4).

8. The tail nozzle structure of claim 7, wherein Along the extending direction of the support arm (5), the width of the support arm (5) is equal.

9. The tail nozzle structure according to any one of claims 5-8, characterized in that, The reinforcing rib is provided with a weight-reducing block (6).

10. The tail nozzle structure according to any one of claims 5-8, characterized in that, The reinforcing ribs are symmetrically arranged on the outer wall surface of the tube body (1).

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