An aircraft having a tail nozzle with a sandwich structure

Abstract

The application provides a sandwich structure tail nozzle, which comprises an inner tube, an outer tube and a support structure, the inner tube and the outer tube are coaxial and tubular structures which are sleeved with each other, the support structure is fixedly arranged in an annular cavity between the outer wall of the inner tube and the inner wall of the outer tube, and the support structure can connect the inner tube and the outer tube as a whole. Through the sandwich structure, the structural rigidity of the tail nozzle can be effectively improved, and the structural weight can be reduced. The support structure between the inner tube and the outer tube is in the flow direction, and there is a smooth airflow channel. When the high-speed gas is sprayed at the tail nozzle end, the pressure near the tail nozzle end is reduced, so that the airflow in the engine cabin can flow to the tail nozzle end through the airflow channel between the inner tube and the outer tube, and an induced airflow is formed. The induced airflow can continuously dissipate heat of the tail nozzle, reduce the temperature of the outer tube of the tail nozzle, and is beneficial to realize long-time cooling and heat insulation.

Description

Technical Field

[0001] This specification relates to the field of aircraft tail nozzle technology, specifically to a sandwich structure tail nozzle. Background Technology

[0002] Modern stealth aircraft, for stealth design considerations, typically have embedded S-shaped air intakes and round-to-square exhaust nozzles located before and after the engine, respectively. The exhaust nozzles, needing to withstand the scouring of the engine's high-temperature exhaust gases, generally reach relatively high temperatures. However, since the exhaust nozzles are embedded within the fuselage, heat insulation and heat dissipation design requirements must be considered to prevent the high temperatures from affecting surrounding structures and onboard equipment. Furthermore, compared to traditional round-section exhaust nozzles, the round-to-square exhaust nozzles have lower local cross-sectional stiffness and are particularly prone to deformation. Therefore, the exhaust nozzles need to be reinforced to maintain their rigidity and prevent compromising performance.

[0003] Traditional tail nozzles typically lack heat dissipation treatment, instead using heat insulation materials to separate the nozzle from surrounding equipment. This insulation method is generally only suitable for short-term use. For long-endurance aircraft, the tail nozzle remains at a high temperature for extended periods, and the accumulated heat can still easily affect nearby equipment. Furthermore, increasing the rigidity of the round-to-square tail nozzle usually requires a significant increase in structural weight, which is detrimental to aircraft weight control. Summary of the Invention

[0004] In view of this, the embodiments of this specification provide a sandwich structure tail nozzle to achieve the purpose of reducing the weight of the tail nozzle and continuous heat dissipation.

[0005] The embodiments in this specification provide the following technical solutions:

[0006] A sandwich-structure tail nozzle, comprising: The inner tube, outer tube, and supporting structure are coaxial and interlocking tubular structures. The supporting structure is fixedly installed in the annular cavity between the outer wall of the inner tube and the inner wall of the outer tube, and the supporting structure can connect the inner tube and the outer tube into a whole.

[0007] Furthermore, the extension direction of the support structure is parallel to the airflow direction of the sandwich structure tail nozzle, and the radial cross section of the support structure is one or a combination of wave-shaped, L-shaped, I-shaped and Z-shaped.

[0008] Furthermore, there are at least four supporting structures.

[0009] Furthermore, the sandwich structure tail nozzle also includes a docking structure, through which the inner tube is connected to the exhaust end of the engine.

[0010] Furthermore, the docking structure is a radially outward flange located at one end of the inner tube, and the connection method between the docking structure and the exhaust end of the engine is one or a combination of threaded connection, bolted connection, clamp connection, and flange connection.

[0011] Furthermore, the outer tube is a tubular structure that extends continuously along the axial direction of the inner tube.

[0012] Furthermore, the outer tube is a multi-segment tubular structure that extends along the axial direction of the inner tube and is distributed at intervals.

[0013] Furthermore, the materials of the inner tube, outer tube, and supporting structure are all high-temperature resistant alloys, and the connection process of the inner tube, outer tube, and supporting structure is argon arc welding.

[0014] Furthermore, the materials of the inner tube, outer tube, and supporting structure are all high-temperature resistant carbon fiber composite materials, and the connection process of the inner tube, outer tube, and supporting structure is co-curing or co-bonding.

[0015] Furthermore, the sandwich structure tail nozzle is positioned between the engine exhaust end and the aircraft skin, with the exhaust end of the sandwich structure tail nozzle inserted into the corresponding opening of the aircraft skin and flush with the corresponding opening of the aircraft skin.

[0016] Compared with the prior art, the beneficial effects that at least one technical solution adopted in the embodiments of this specification can achieve include at least: The tailpipe employs a sandwich structure, which effectively improves structural rigidity while reducing weight. A support structure aligned with the airflow direction connects the inner and outer pipes, providing a smooth airflow channel. When the exhaust gas is ejected at high speed from the tailpipe tip, the nearby pressure decreases, allowing airflow from the engine compartment to flow through the airflow channel between the inner and outer pipes towards the tailpipe tip, forming an ejector jet. This ejector jet continuously dissipates heat from the tailpipe, reducing the temperature of the outer pipe and facilitating long-term cooling and insulation. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the 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.

[0018] Figure 1 This is a schematic diagram of the overall structure of the sandwich structure tail nozzle according to an embodiment of the present invention; Figure 2 This is a cross-sectional view of the tail nozzle of the sandwich structure according to an embodiment of the present invention, perpendicular to the airflow direction; Figure 3This is a cross-sectional view of the tail nozzle of the sandwich structure in an embodiment of the present invention, parallel to the airflow direction; Figure 4 This is an embodiment of the present invention. Figure 3 A partial schematic diagram of the tail section of the sandwich structure tail nozzle.

[0019] Explanation of reference numerals in the attached drawings: 1. Inner tube; 2. Support structure; 3. Outer tube; 4. Docking structure; 5. Aircraft skin. Detailed Implementation

[0020] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0021] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this application, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0023] It should also be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0024] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0025] refer to Figure 1 The sandwich-structured exhaust nozzle is located between the engine tail and the aircraft skin 5. The sandwich-structured exhaust nozzle consists of an inner tube 1, an outer tube 3, and a support structure 2. The support structure 2, parallel to the airflow direction, is fixed to the outside of the inner tube 1. The outer tube 3 is fixed to the outside of the support structure 2. A detachable docking structure 4 is provided at the front end of the inner tube 1 for connecting the inner tube 1 to the engine tail. The docking structure 4 can be connected by threaded connections, bolted connections, clamp connections, flange connections, etc.

[0026] The supporting structure 2 extends parallel to the airflow direction of the sandwich structure nozzle, dividing the hollow airflow channel between the inner pipe 1 and the outer pipe 3 into several parts. The radial cross-sectional shape of the supporting structure 2 can be set according to actual strength and weight requirements. The radial cross-sectional shape of the supporting structure 2 can be wavy, L-shaped, I-shaped, or Z-shaped, etc. (Reference) Figure 2 In this embodiment, a support structure 2 with a wavy cross-section is used. Because the radial cross-section of the tail nozzle is approximately square, to ensure that all four sides of the inner pipe 1 and outer pipe 3 can be positioned and connected, the number of support structures 2 is typically no less than four. For example... Figure 2 As shown, this embodiment uses 6 ribs. If the sandwich structure nozzle requires greater rigidity, the number of support structures 2 can be increased. It should be noted that increasing the number of support structures 2 will correspondingly increase the weight of the entire sandwich structure nozzle, so it needs to be set according to the actual application scenario.

[0027] The exhaust end of the sandwich structure nozzle is inserted into the corresponding opening of the aircraft skin 5. The aircraft skin 5 and the sandwich structure nozzle are only in contact but not fixedly connected. The radial dimension of the outer tube 3 of the sandwich structure nozzle is slightly smaller than the opening size of the aircraft skin 5. When the aircraft engine is working, the sandwich structure nozzle expands axially due to heat. The sandwich structure nozzle can slide relative to the aircraft skin 5 along the airflow direction.

[0028] refer to Figure 3The outer tube 3 is a thin-walled structure, fixed to the outside of the supporting structure 2. In this embodiment, the outer tube 3 is a continuous and complete tubular structure. The inner tube 1 is also a thin-walled structure, with its inner surface serving as a high-temperature combustion gas passage for the engine. It is connected to the outer tube 3 through the supporting structure 2, forming an integral sandwich structure. The sandwich structure provides good structural rigidity and forms an airflow channel between the inner tube 1 and the outer tube 3. When the high-temperature combustion gas from the engine is ejected at high speed through the inner tube 1, the pressure at the end of the sandwich structure's nozzle decreases, allowing the airflow in the engine compartment to flow through the airflow channel between the inner and outer tubes to the outlet end of the sandwich structure's nozzle, forming an ejector airflow. The ejector airflow not only helps dissipate heat from the engine compartment but also continuously removes heat from the nozzle, achieving long-term heat insulation and cooling of the nozzle. A smooth airflow channel can be formed between the outer tube 3 and the inner tube 1. By adjusting the cross-sectional dimensions of the outer tube 3, the size of the airflow channel can be adjusted so that the final ejector airflow can meet the heat dissipation requirements of the nozzle.

[0029] In other embodiments, to reduce the overall weight of the sandwich structure nozzle, the outer tube 3 can also be a multi-segment annular structure with intervals, used to improve overall rigidity at key locations or for connection with other parts. That is, along the airflow direction of the sandwich structure nozzle, there are structural segments with the inner tube 1 and the support structure 2 covered by the outer tube 3, and there are also structural segments consisting only of the inner tube 1 and the support structure 2.

[0030] It should be noted that, for overall stealth considerations, the tail nozzle should not exceed the aerodynamic shape of the aircraft; that is, the tail nozzle of the sandwich structure should not extend beyond the aircraft skin. (Reference) Figure 4 In the enlarged view of the tail section of the sandwich structure nozzle, at the junction of the sandwich structure nozzle and the aircraft skin 5, the lengths of the inner tube 1, the support structure 2, and the outer tube 3 of the sandwich structure nozzle do not exceed the length of the aircraft skin 5.

[0031] In some implementations, the aircraft engine exhaust temperature is high, and the sandwich structure tail nozzle can be made of high-temperature resistant alloys or high-temperature resistant stainless steel and formed using sheet metal processing. Correspondingly, the connection between the inner tube 1, the support structure 2 and the outer tube 3 is a metal welding process such as argon arc welding.

[0032] In other embodiments, where the aircraft engine exhaust temperature is relatively low, the sandwich-structured tailpipe can be made of high-temperature resistant carbon fiber composite material. Correspondingly, the connection between the inner tube 1, the support structure 2, and the outer tube 3 employs co-curing or co-bonding processes. It should be noted that co-curing is a process where two or more composite material parts with a connection relationship are simultaneously cured and bonded into a single part within a single curing cycle. Co-bonding involves bonding one or more cured parts with one or more uncured parts together using an adhesive.

[0033] The sandwich structure tail nozzle combines high rigidity and lightweight characteristics, while also meeting the long-term heat dissipation requirements of the tail nozzle and aiding in the heat dissipation of the engine compartment, thus well meeting the various performance requirements of modern stealth aircraft.

[0034] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on describing the differences from other embodiments. In particular, the method embodiments described later are relatively simple in description because they correspond to the system; relevant parts can be referred to the descriptions in the system embodiments.

[0035] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An aircraft with a sandwich-structured tail nozzle, characterized in that, include: The inner tube (1), outer tube (3) and support structure (2) are coaxial and interlocked tubular structures. The support structure (2) is fixedly installed in the annular cavity between the outer wall of the inner tube (1) and the inner wall of the outer tube (3). The support structure (2) can connect the inner tube (1) and the outer tube (3) into a whole. The extension direction of the support structure (2) is parallel to the airflow direction of the sandwich structure tail nozzle, and the radial section of the support structure (2) is one or a combination of wave-shaped, L-shaped, I-shaped and Z-shaped. The inner tube (1), outer tube (3) and support structure (2) allow the airflow in the engine compartment to flow through the airflow channel between the inner tube (1) and the outer tube (3) to the end of the tail nozzle, forming an ejector airflow. The ejector airflow can be used to continuously dissipate heat from the tail nozzle and reduce the temperature of the outer tube of the tail nozzle. The outer tube (3) is a multi-segment tubular structure that extends along the axial direction of the inner tube (1) and is distributed at intervals; The materials of the inner tube (1), outer tube (3) and support structure (2) are all high-temperature resistant carbon fiber composite materials, and the connection process of the inner tube (1), outer tube (3) and support structure (2) is co-curing or co-bonding. The lengths of the inner tube (1), outer tube (3) and support structure (2) do not exceed the aircraft skin (5). The sandwich structure tail nozzle is disposed between the engine exhaust end and the aircraft skin (5). The exhaust end of the sandwich structure tail nozzle is inserted into the corresponding opening of the aircraft skin (5) and is flush with the corresponding opening of the aircraft skin (5). The aircraft skin (5) and the sandwich structure tail nozzle are only in contact but not fixedly connected. The radial dimension of the outer tube (3) is slightly smaller than the opening size of the aircraft skin (5), so that when the engine is working, the sandwich structure tail nozzle can slide relative to the aircraft skin (5) along the airflow direction when it is heated and axially expanded.

2. The aircraft with a sandwich-structured tail nozzle according to claim 1, characterized in that, The supporting structure (2) has at least 4 components.

3. The aircraft with a sandwich-structured tail nozzle according to claim 1, characterized in that, The sandwich structure tail nozzle also includes a docking structure (4), and the inner tube (1) is connected to the exhaust end of the engine through the docking structure (4).

4. The aircraft with a sandwich-structured tail nozzle according to claim 3, characterized in that, The docking structure (4) is a radially outward flange set at one end of the inner tube (1). The connection method between the docking structure (4) and the exhaust end of the engine is one or a combination of threaded connection, bolt connection, clamp connection, and flange connection.

5. The aircraft with a sandwich-structured tail nozzle according to claim 1, characterized in that, The outer tube (3) is a tubular structure that extends along the axial direction of the inner tube (1) and is continuously distributed.

6. The aircraft with a sandwich-structured tail nozzle according to claim 1, characterized in that, The materials of the inner tube (1), outer tube (3) and support structure (2) are all high-temperature resistant alloys, and the connection process of the inner tube (1), outer tube (3) and support structure (2) is argon arc welding.

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