An integrated composite nozzle based on metal insert reinforcement and its manufacturing method

Abstract

This application discloses an integrated composite nozzle reinforced with a metal insert and its manufacturing method, relating to the field of aircraft engine nozzle technology. The nozzle, from the inside out, includes an inner ablation layer, an inner heat insulation layer, a support structure, an outer heat insulation layer, and an outer ablation layer. The inner wall of the inner ablation layer near the nozzle inlet end is provided with a throat liner. The support structure includes: a composite material layup laid between the inner and outer heat insulation layers, with an outwardly protruding limiting mounting seat; a metal insert fitted onto the composite material layup and abutting against the limiting mounting seat on the side near the nozzle inlet end; and an outer heat insulation layer extending from the nozzle inlet end to the metal insert and abutting against it. This application not only increases structural strength and stiffness and reduces structural deformation but also ensures reliable sealing between the nozzle and the combustion chamber, improving structural reliability to match the pressure load on the nozzle structure under aircraft engine operating conditions, enabling application in harsh nozzle environments.

Description

Technical Field

[0001] This application relates to the field of aircraft engine nozzle technology, specifically to an integrated composite nozzle based on metal insert reinforcement and its manufacturing method. Background Technology

[0002] As a key component of an aircraft engine, the reliability of the nozzle directly affects the success or failure of the entire engine energy conversion process. While ensuring its thermal protection performance is reliable, its rigidity needs to be increased and its deformation reduced to ensure the reliability of the sealing structure and achieve stable operation of the nozzle.

[0003] In related technologies, nozzles include a throat liner, an ablation-resistant layer, a heat insulation layer, and a shell load-bearing layer. Previously, the ablation-resistant layer, heat insulation layer, and shell load-bearing layer of nozzles were each assembled from numerous components, and then the components were assembled into a nozzle. This not only resulted in numerous components and a long molding time, but also created significant gaps between the components, making the structure prone to reliability issues. Furthermore, the high density of the supporting structure, while increasing strength, also led to an increase in inertial mass. Summary of the Invention

[0004] In view of the deficiencies in the existing technology, the purpose of this application is to provide an integrated composite nozzle based on metal insert reinforcement and its manufacturing method, so as to solve the problems of many nozzle components, long molding time and insufficient structural reliability in the related technology.

[0005] The first aspect of this application provides an integrated composite nozzle based on metal insert reinforcement, which includes, from the inside out, an inner ablation layer, an inner heat insulation layer, a support structure, an outer heat insulation layer, and an outer ablation layer. The inner ablation layer has a throat liner on its inner wall near the nozzle inlet end. The support structure includes:

[0006] A composite material layup is laid between the inner insulation layer and the outer insulation layer, and the composite material layup is provided with an outwardly protruding limiting mounting seat.

[0007] A metal insert is fitted onto the aforementioned composite material layup and abuts against the side of the aforementioned limiting mounting seat near the nozzle inlet end;

[0008] The aforementioned external heat insulation layer extends from the inlet end of the nozzle to the aforementioned metal insert and abuts against the aforementioned metal insert.

[0009] In some embodiments, the metal insert includes a reinforcing ring and an annular plate sleeved on one end of the reinforcing ring, with a plurality of ribs spaced apart between the reinforcing ring and the annular plate, and the inner surface of the reinforcing ring being an inwardly tapered surface.

[0010] In some embodiments, rigid foam is filled between adjacent ribs, and carbon cloth is laid on the side of the rigid foam away from the reinforcing ring and the annular plate.

[0011] In some embodiments, at least one surface of the composite material layup, or the surface of the inner or outer insulation layer facing the composite material layup, is provided with grooves.

[0012] In some embodiments, multiple corner boxes are fixedly installed between the side of the limiting mounting base away from the metal insert and the outer annular surface of the composite material layup.

[0013] In some embodiments, the end of the composite material layup near the nozzle inlet extends into the gap formed by the inner and outer insulation layers.

[0014] In some embodiments, the inner and outer heat insulation layers extend into the gap formed by the inner and outer ablation layers at the end near the nozzle inlet.

[0015] In some embodiments, the throat liner is a rotating body with an integral structure or a rotating body composed of modular structures, and the throat liner is made of carbon / carbon composite material.

[0016] In some embodiments, a first elastic layer is laid between the composite material layup and the inner insulation layer, and a second elastic layer is laid on both the front and rear conical surfaces connecting the throat liner and the inner ablation layer.

[0017] A second aspect of this application provides a method for manufacturing the aforementioned integrated composite nozzle based on metal insert reinforcement, comprising the steps of:

[0018] The thickness of the composite material layup is determined based on the operating load of the nozzle.

[0019] Starting with the throat liner as the initial layer, the inner ablation layer, the inner heat insulation layer, and the composite material layup are sequentially composited from the inside out.

[0020] The metal insert is fitted and fixed onto the composite material layup and abuts against the side of the limiting mounting seat near the nozzle inlet. Then, the outer heat insulation layer and the outer ablation layer are laminated in sequence. The outer heat insulation layer abuts against the metal insert.

[0021] The beneficial effects of the technical solution provided in this application include:

[0022] This application discloses an integrated composite nozzle reinforced with a metal insert and its manufacturing method. The nozzle's support structure includes a composite material ply and a metal insert. The composite material ply has an outwardly protruding limiting mounting seat. The metal insert is fitted onto the composite material ply and abuts against the limiting mounting seat on the side near the nozzle inlet end. An external heat insulation layer extends from the nozzle inlet end to the metal insert and abuts against it. The support structure formed by the composite material ply and the metal insert not only increases structural strength and stiffness and reduces structural deformation, but also ensures reliable sealing between the nozzle and the combustion chamber, improving structural reliability. This allows it to match the pressure load on the nozzle structure under the operating environment of an aircraft engine, enabling applications in harsh nozzle environments. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the axial cross-sectional structure of the integrated composite nozzle based on metal insert reinforcement in the embodiments of this application;

[0025] Figure 2 for Figure 1 A magnified view of a portion of point A in the middle;

[0026] Figure 3 This is a schematic diagram of the structure of the metal insert in the embodiments of this application.

[0027] Figure label:

[0028] 1. Throat liner; 2. Inner ablation layer; 3. Outer ablation layer; 4. Inner insulation layer; 5. Outer insulation layer; 6. Composite material layup; 61. Limiting mounting base; 7. Metal insert; 71. Reinforcing ring; 72. Annular plate; 73. Rib plate; 8. Corner box. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this application clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] like Figure 1 and Figure 2As shown, this application provides an integrated composite nozzle based on metal insert reinforcement. The nozzle, from the inside out, includes an inner ablation layer 2, an inner heat insulation layer 4, a support structure, an outer heat insulation layer 5, and an outer ablation layer 3. A throat liner 1 is provided on the inner wall of the inner ablation layer 2 near the nozzle inlet. In this embodiment, the throat liner 1 is used as the starting component, and the inner ablation layer 2, inner heat insulation layer 4, support structure, outer heat insulation layer 5, and outer ablation layer 3 are sequentially formed into an integrated nozzle along the inner wall to the outer wall. The inner ablation layer 2 is formed on the outer surface of the throat liner 1, and the material of the inner ablation layer 2 is a carbon cloth / phenolic composite material. The process can be carried out using a combination of winding and laying methods.

[0031] The aforementioned support structure includes a composite material layup 6 and a metal insert 7. The composite material layup 6 is laid between the inner insulation layer 4 and the outer insulation layer 5, meaning that both the inner and outer sides of the composite material layup 6 are wrapped with insulation layers. The composite material layup 6 is provided with an outwardly protruding limiting mounting seat 61. The metal insert 7 is fitted between the composite material layup 6 and the outer insulation layer 5, and abuts against the limiting mounting seat 61 on the side near the nozzle inlet end. The outer insulation layer 5 extends from the nozzle inlet end to the metal insert 7, and abuts against the side of the metal insert 7 near the nozzle inlet end.

[0032] In this embodiment, the metal insert 7 is connected to the composite material layup 6 by screws and adhesive.

[0033] This embodiment features an integrated composite nozzle reinforced with a metal insert. The nozzle's support structure comprises a composite material layup and a metal insert. The composite material layup has an outwardly protruding limiting mounting seat. The metal insert is fitted onto the composite material layup and abuts against the limiting mounting seat near the nozzle inlet end. An external heat insulation layer extends from the nozzle inlet end to the metal insert and abuts against it. Therefore, the support structure formed by the composite material layup and the metal insert not only increases structural strength and stiffness and reduces structural deformation, but also ensures reliable sealing between the nozzle and the combustion chamber, improving structural reliability. This allows it to match the pressure load on the nozzle structure under the operating environment of an aircraft engine, enabling applications in harsh nozzle environments.

[0034] In some embodiments, a pure composite material layup structure can also be used as the support structure. By adjusting the material type during the winding process, the functions of ablation, heat insulation, and support structure in the nozzle can be achieved. The nozzle support structure and the combustion chamber flange are connected by bolts, inevitably leaving a certain gap. Even if the gap is sealed with putty and sealing strips, the pure composite material layup structure suffers from high circumferential and axial strength but poor radial interlayer strength due to the limitations of its winding / layout molding method. That is, due to the anisotropy of the mechanical properties of composite materials, its strain performance is poor when facing loads in a specific direction. Under pressures of 10 MPa and higher, large deformation will occur, which will have a very adverse effect on the sealing and can easily lead to launch failure of the aircraft. Therefore, in view of the insufficient radial mechanical properties of composite materials under high pressure, metal inserts are added to the support structure and structural design is carried out to achieve small deformation of the support structure under high pressure, thus ensuring the normal operation of the engine.

[0035] like Figure 3 As shown, based on the above embodiments, in this embodiment, the metal insert 7 includes a reinforcing ring 71 and an annular plate 72. The annular plate 72 is sleeved on one end of the reinforcing ring 71, and the inner surface of the reinforcing ring 71 is an inwardly tapered surface. As a key component of the support structure, the metal insert 7, through reasonable structural design, can achieve improved strength and stiffness to meet the requirements of low deformation and high reliability of the nozzle under high pressure.

[0036] Optionally, the outer ring surface of the reinforcing ring 71 abuts against the aforementioned outer heat insulation layer, and the inner ring surface of the reinforcing ring 71 abuts against the end face of the annular plate 72 away from the reinforcing ring 71 and the limiting mounting seat 61.

[0037] Furthermore, a plurality of ribs 73 are provided at intervals between the reinforcing ring 71 and the annular plate 72, and rigid foam is filled between adjacent ribs 73. Carbon cloth is laid on the side of the rigid foam away from the reinforcing ring 71 and the annular plate 72, and the rigid foam can be constrained by laying carbon cloth on the surface of the rigid foam. The pressure on the annular plate 72 during nozzle operation can be transmitted to the reinforcing ring 71 through the ribs 73.

[0038] Preferably, the rigid foam is thermal insulation foam, which is filled between adjacent ribs 73 by carbon cloth and rigid foam. This greatly increases the load-bearing area of ​​the metal insert 7 while slightly increasing its mass, and further solves the problem of weak bending stiffness of pure composite material ply structures under large bending moments.

[0039] In this embodiment, the edge of the limiting mounting seat 61 is provided with a plurality of mounting holes, and the edge of the annular plate 72 is provided with connection holes corresponding to the mounting holes, so that the composite material lay-up 6 and the metal insert 7 can be connected to the rear connector of the engine combustion chamber housing by bolts to become a submersible nozzle.

[0040] Optionally, the aforementioned limiting mounting seat 61 is a connecting flange, which is integrally formed on the outer surface of the aforementioned composite material layup 6. In this embodiment, compared with a pure composite material support structure of the same thickness, the support structure with added metal inserts reduces the deformation of the nozzle during operation by about 20%, and the weight is increased by about 5% compared with the pure composite support structure. This achieves a significant increase in load-bearing capacity and reduces deformation at the cost of a slight increase in weight, thereby improving the reliability of the engine during operation.

[0041] In this embodiment, at least one surface of the composite material layup 6, or the surface of the inner insulation layer 4 or the outer insulation layer 5 facing the composite material layup 6, is provided with grooves to reduce residual stress.

[0042] Optionally, grooves may be provided only on the surface of the composite material layup 6 facing the inner insulation layer 4, or grooves may be provided on the surface of the composite material layup 6 facing the outer insulation layer 5.

[0043] Optionally, grooves may be provided only on the surface of the inner insulation layer 4 facing the composite material layup 6 or on the surface of the outer insulation layer 5 facing the composite material layup 6.

[0044] Optionally, the metal insert 7 of the aforementioned support structure is made of aluminum, high-strength steel, or titanium. Preferably, the metal insert is made of high-strength aluminum, and the composite material layup 6 is made of carbon fiber / epoxy resin laid out according to the load-bearing requirements.

[0045] Furthermore, a plurality of corner boxes 8 are fixedly installed between the side of the limiting mounting base 61 away from the metal insert 7 and the outer annular surface of the composite material layup 6. Preferably, the corner box 8 is a metal corner box, which increases the connection strength between the nozzle and the engine support structure.

[0046] This embodiment addresses the significant anisotropy of composite material layup structures, where the strength and modulus in the layup direction are significantly lower than those in the fiber direction, resulting in shortcomings and bottlenecks such as low interlaminar strength and stiffness. A high-strength metal insert, together with the carbon fiber / epoxy composite layup, forms a support structure surrounding the inner ablation layer and inner insulation layer, achieving pressure-bearing functionality, reducing nozzle support structure deformation, and improving support structure stiffness. It also effectively solves the problem of insufficient interlaminar strength and stiffness when using composite materials alone as a support structure, achieving the goals of low cost, lightweight, and high reliability for the nozzle. Specific material selection, as well as the structural form and proportions of the metal insert, can be adjusted according to the actual operating conditions of the engine nozzle and the capabilities of the product equipment.

[0047] In this embodiment, the end of the composite material layup 6 near the nozzle inlet extends into the gap formed by the inner insulation layer 4 and the outer insulation layer 5.

[0048] Furthermore, the inner heat insulation layer 4 and the outer heat insulation layer 5 extend from the end near the nozzle inlet into the gap formed by the inner ablation layer 2 and the outer ablation layer 3.

[0049] Based on the above embodiments, in this embodiment, the throat liner 1 is a rotating body with an integral structure or a rotating body composed of modular structures, and the throat liner 1 is made of carbon / carbon composite material. In this embodiment, the throat liner 1 is made of carbon / carbon needle-punched composite material.

[0050] Optionally, a first elastic layer is laid between the aforementioned composite material layup 6 and the inner insulation layer 4. This first elastic layer helps to alleviate residual structural stress under temperature shock. The material of this first elastic layer can be selected according to the operating conditions.

[0051] Preferably, a second elastic layer is laid on both the front and rear conical surfaces connecting the throat liner 1 and the inner ablation layer 2 to further alleviate residual structural stress under temperature shock. This second elastic layer is made of silicone rubber gaskets or a toughening adhesive. In this embodiment, the nozzle inlet end is considered the front.

[0052] This application also provides a method for manufacturing the above-mentioned integrated composite nozzle based on metal insert reinforcement, the method comprising the following steps:

[0053] S1. Determine the thickness of composite material layup 6 based on the operating load of the nozzle.

[0054] Optionally, the composite material layup 6 is made of T700 carbon fiber / epoxy resin and is prepared by a layup process.

[0055] S2. Taking throat liner 1 as the starting layer, the inner ablation layer 2, the inner heat insulation layer 4 and the composite material layup 6 are sequentially composited from the inside to the outside.

[0056] S3. The metal insert 7 is fitted and fixed onto the composite material layup 6 and abuts against the side of the limiting mounting seat 61 near the nozzle inlet. Then, the outer heat insulation layer 5 and the outer ablation layer 3 are laminated in sequence. The outer heat insulation layer 5 abuts against the side of the metal insert 7 near the nozzle inlet.

[0057] In this embodiment, the throat liner 1 is located in the area of ​​most severe nozzle ablation and can be made of carbon / carbon needle-punched composite material, composed of modularly assembled rotating bodies to improve its resistance to ablation. The inner ablation layer 2 and the outer ablation layer 3 are formed by winding carbon cloth / phenolic composite material. Depending on the ablation condition, the front section of the nozzle is wound obliquely, and after reaching a certain expansion ratio, it is wound flatly. 3K carbon cloth is used in the obliquely wound area, and 1K carbon cloth is used in the flat wound area. The inner heat insulation layer 4 and the outer heat insulation layer 5 of the nozzle are formed by winding high-silica / phenolic composite material to enhance their heat insulation capacity and ensure that the supporting structure does not experience a temperature rise. The expansion ratio can be determined according to the nozzle design structure.

[0058] Preferably, the metal insert 7 includes a reinforcing ring 71, ribs 73, and an annular plate 72. The annular plate 72 is fitted onto one end of the reinforcing ring 71, and the inner surface of the reinforcing ring 71 is an inwardly tapered surface. Multiple ribs 73 are spaced apart between the reinforcing ring 71 and the annular plate 72, and rigid foam is filled between adjacent ribs 73. Carbon cloth is laid on the side of the rigid foam away from the reinforcing ring 71 and the annular plate 72. In this embodiment, the inner surface of the metal insert 7 matches the outer surface of the composite material layup 6.

[0059] Based on the above embodiments, in this embodiment, the metal insert 7 is sleeved and fixed on the composite material layup 6 and abuts against the limiting mounting seat 61 near the nozzle inlet end, specifically including the following steps:

[0060] A1. The metal insert 7 is fitted onto the composite material layup 6 and fixed to the surface of the composite material layup 6 by screws and adhesive.

[0061] A2. Fill the space between adjacent ribs 73 of the metal insert 7 with rigid foam and fix it with carbon cloth on the surface of the rigid foam.

[0062] Furthermore, the aforementioned support structure also includes a metal corner box, which is fixedly installed between the side of the limiting mounting base 61 away from the metal insert 7 and the outer ring surface of the composite material layup 6.

[0063] Preferably, before the composite material layup 6 is laminated onto the surface of the inner heat insulation layer 4, a soft elastic material can be laid on the surface of the inner heat insulation layer 4 to form a first elastic layer, so as to alleviate the thermal stress of the nozzle operation.

[0064] The manufacturing method of this embodiment is applicable to the aforementioned integrated composite nozzles reinforced with metal inserts. By eliminating large metal structural components and numerous assembly interfaces, it can reduce weight by more than 20%, significantly improving the aircraft's carrying capacity. Simultaneously, it eliminates the macroscopic assembly interfaces of the nozzle, simplifying the process flow, shortening labor time, and saving costs. Furthermore, using a combination of high-strength metal inserts and composite material layups as the nozzle's support structure improves the material's structural efficiency, further achieving lightweighting while ensuring structural strength and stiffness. It also mitigates the problem of weak shear deformation resistance in composite materials, enabling the application of high-strength, lightweight metal inserts in harsh nozzle environments. Simultaneously, the addition of metal materials reduces the deformation degree of the support structure, preventing arcing due to deformation and subsequent structural weakness leading to launch failure, thus greatly improving engine reliability.

[0065] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0066] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0067] The above are merely specific embodiments of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. An integrated composite nozzle based on metal insert reinforcement, characterized in that, It comprises, from the inside out, an inner ablation layer (2), an inner heat insulation layer (4), a support structure, an outer heat insulation layer (5), and an outer ablation layer (3). The inner ablation layer (2) has a throat liner (1) on its inner wall near the nozzle inlet end. The support structure includes: A composite material layup (6) is laid between the inner insulation layer (4) and the outer insulation layer (5), and the composite material layup (6) is provided with an outwardly protruding limiting mounting seat (61). A metal insert (7) is fitted onto the composite material layup (6) and abuts against the side of the limiting mounting seat (61) near the nozzle inlet end; The outer heat insulation layer (5) extends from the inlet end of the nozzle to the metal insert (7) and abuts against the metal insert (7); The metal insert (7) includes a reinforcing ring (71) and an annular plate (72) sleeved on one end of the reinforcing ring (71). A plurality of ribs (73) are spaced apart between the reinforcing ring (71) and the annular plate (72). The inner surface of the reinforcing ring (71) is an inwardly tapered surface. Rigid foam is filled between adjacent ribs (73), and carbon cloth is laid on the side of the rigid foam away from the reinforcing ring (71) and the annular plate (72); The metal insert (7) is connected to the composite material layup (6) by screws and adhesive.

2. The integrated composite nozzle based on metal insert reinforcement as described in claim 1, characterized in that: At least one surface of the composite material layup (6), or the inner insulation layer (4) or the outer insulation layer (5) facing the surface of the composite material layup (6), has a groove.

3. The integrated composite nozzle based on metal insert reinforcement as described in claim 1, characterized in that: Multiple corner boxes (8) are fixedly installed between the side of the limiting mounting base (61) away from the metal insert (7) and the outer ring surface of the composite material layup (6).

4. The integrated composite nozzle based on metal insert reinforcement as described in claim 1, characterized in that: The composite material layup (6) extends from one end near the nozzle inlet into the gap formed by the inner insulation layer (4) and the outer insulation layer (5).

5. The integrated composite nozzle based on metal insert reinforcement as described in claim 1, characterized in that: The inner heat insulation layer (4) and the outer heat insulation layer (5) extend from one end near the nozzle inlet into the gap formed by the inner ablation layer (2) and the outer ablation layer (3).

6. The integrated composite nozzle based on metal insert reinforcement as described in claim 1, characterized in that: The throat liner (1) is a rotating body with an integral structure or a rotating body composed of modular structures. The throat liner (1) is made of carbon / carbon composite material.

7. The integrated composite nozzle based on metal insert reinforcement as described in claim 6, characterized in that: A first elastic layer is laid between the composite material layup (6) and the inner insulation layer (4), and a second elastic layer is laid on both the front and rear conical surfaces connecting the throat liner (1) and the inner ablation layer (2).

8. A method for manufacturing an integrated composite nozzle based on metal insert reinforcement as described in claim 1, characterized in that, It includes the following steps: The thickness of the composite material layup (6) is determined based on the operating load of the nozzle; Using the throat liner (1) as the starting layer, the inner ablation layer (2), the inner heat insulation layer (4), and the composite material layup (6) are sequentially composited from the inside to the outside. The metal insert (7) is fitted and fixed on the composite material layup (6) and abuts against the side of the limiting mounting seat (61) near the nozzle inlet end. Then, the outer heat insulation layer (5) and the outer ablation layer (3) are laminated in sequence. The outer heat insulation layer (5) abuts against the metal insert (7).

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