Engine jet pipe and engine
Through split structure design and optimized material selection, the problem of high cost of existing RBCC engine nozzles is solved, and the effect of reducing use and total cost is achieved. Only the damaged part is replaced, the material cost is reduced, and the structural strength and lightness are improved. Quantification.
Patent Information
- Application Number
- CN202411258472.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-09
- Publication Date
- 2024-12-17
AI Technical Summary
The existing RBCC engine nozzles are made of integral ceramic matrix composite materials, resulting in higher usage costs, increasing the total cost of the engine.
The design of split structure includes inner lining, outer lining and protective cover. The outer lining is installed outside the inner lining and the protective cover is installed outside the outer lining. It is replaced only in the damaged part, which reduces the overall replacement requirement, and the cost of use. Total cost. The inner lining is made of ceramic-based composite material, and the outer lining is a resin-based composite material. The wall thickness design is optimized to reduce the weight and cost of the nozzle.
The use cost and total cost of engine nozzles is achieved, and only the damaged parts are replaced through the split design, which reduces the demand for overall replacement, reduces the cost of materials, and improves structural strength and lightweight through optimizing material and structural design.
Smart Images
Figure CN119145980A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of aerospace engines, and in particular to an engine nozzle and an engine. Background Art
[0002] In order to adapt to the working requirements in a wide speed range, the nozzle of the RBCC (Rocket-Based Combined Cycle) engine is generally designed as a pure expansion configuration. Compared with the Laval nozzle, the severity of its working environment (such as the local maximum heat flux density) is reduced.
[0003] However, the RBCC engine nozzle in the prior art is generally made of ceramic-based composite materials, which often have high usage costs and increase the cost of the engine. Summary of the invention
[0004] The object of the present invention is to provide an engine nozzle and an engine, which are used to reduce the use cost of the engine nozzle and further reduce the cost of the engine.
[0005] In order to achieve the above-mentioned object, in a first aspect, the present invention provides an engine nozzle having an inlet end and an outlet end connected to each other. The engine nozzle comprises an inner liner, an outer liner and a protective cover, wherein the inner liner has a cavity that passes through from the inlet end to the outlet end. The outer liner is sleeved outside the inner liner, and the protective cover is sleeved outside the outer liner.
[0006] When the above technical solution is adopted, the engine nozzle includes an inner lining, an outer lining and a protective cover. The outer lining is arranged outside the inner lining, and the protective cover is arranged outside the outer lining. This shows that the structure of the engine nozzle is split. When the outer lining or protective cover of the engine nozzle is damaged and needs to be replaced, only the damaged part needs to be replaced, and there is no need to replace the engine nozzle as a whole, which reduces the use cost of the engine nozzle and further reduces the cost of the engine.
[0007] In a possible implementation, the material of the lining is a ceramic-based composite material.
[0008] In a possible implementation, the material of the lining is carbon fiber with silicon carbide deposited on the surface.
[0009] In a possible implementation, the material of the outer lining is a resin-based composite material.
[0010] In a possible implementation, the composite material matrix of the outer lining is phenolic resin, and the reinforcement of the outer lining is quartz fiber, high silica fiber or carbon fiber.
[0011] In a possible implementation, the outer wall of the inner liner and the inner wall of the outer liner are bonded and connected via a transition layer.
[0012] In a possible implementation, the transition layer is a carbon fiber cloth impregnated with phenolic resin.
[0013] In a possible implementation, the ratio of the wall thickness of the inner liner, the wall thickness of the carbon fiber cloth impregnated with phenolic resin, and the wall thickness of the outer liner is 1.5:1:3 to 2:1:3.
[0014] In a possible implementation, the wall thickness of the inner liner and / or the wall thickness of the outer liner gradually decreases along the direction from the inlet end to the outlet end.
[0015] In a second aspect, the present invention provides an engine, comprising a combustion chamber and an engine nozzle as described in the first aspect and any possible implementation of the first aspect, wherein an inlet end of the engine nozzle is arranged at an outlet end of the combustion chamber.
[0016] The beneficial effects of the engine described in the second aspect can refer to the beneficial effects of the engine nozzle described in the first aspect, and will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:
[0018] Figure 1 A schematic diagram of an engine nozzle provided in an embodiment of the present invention.
[0019] Reference numerals:
[0020] 1-Inner lining, 2-Outer lining, 3-Protective cover, 4-Transition layer. DETAILED DESCRIPTION
[0021] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0022] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.
[0023] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The meaning of "several" is one or more, unless otherwise clearly and specifically defined.
[0024] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "up", "down", "front", "back", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.
[0025] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0026] The rocket-based combined cycle engine (RBCC engine for short) organically combines the ramjet engine and the rocket engine, taking into account both high specific impulse and large thrust-to-weight ratio, and has good application prospects in the future. Compared with a simple ramjet engine, the RBCC engine, as a missile power device, can enable the missile body to have good acceleration and maneuverability.
[0027] In order to reduce system complexity and product structural quality, RBCC engines need to use a large number of new high-temperature resistant low-density composite materials, which leads to a significant increase in engine cost. At present, missile RBCC engine nozzles are usually made of high-temperature resistant ceramic-based composite materials, which means that the current missile RBCC engine nozzles are generally an integral structure, and the material is high-temperature resistant ceramic-based composite materials. Due to the high cost of high-temperature resistant ceramic-based composite materials, the cost of the engine increases.
[0028] In order to adapt to the working requirements in a wide speed range (taking into account both subsonic and scramjet modes), the RBCC engine nozzle is generally designed as a pure expansion configuration. Compared with the traditional Laval nozzle, the severity of its working environment (such as the local maximum heat flux density) is reduced, thus making it possible to use low-cost materials.
[0029] In view of this, see Figure 1 As shown, an embodiment of the present invention provides an engine nozzle, which has an inlet end and an outlet end that are connected to each other. The engine nozzle includes an inner liner 1, an outer liner 2 and a protective cover 3, as shown in FIG. Figure 1 As shown, the inner liner 1 has a cavity that runs through from the inlet end to the outlet end. The outer liner 2 is sleeved outside the inner liner 1 , and the protective cover 3 is sleeved outside the outer liner 2 .
[0030] When the above technical solution is adopted, the engine nozzle includes an inner lining 1, an outer lining 2 and a protective cover 3. The outer lining 2 is sleeved on the outside of the inner lining 1, and the protective cover 3 is sleeved on the outside of the outer lining 2. This shows that the structure of the engine nozzle is a split type. When the outer lining 2 or the protective cover 3 of the engine nozzle is damaged and needs to be replaced, only the damaged part needs to be replaced, and there is no need to replace the engine nozzle as a whole, which reduces the use cost of the engine nozzle and further reduces the cost of the engine.
[0031] In specific implementation, the outermost layer of the nozzle provided by the embodiment of the present invention can be a metal protective cover 3. The protective cover 3 serves as a reinforced protective cover to further improve the structural strength margin of the nozzle, and the nozzle structure mass can be reduced as much as possible by optimizing the design of the protective cover 3. For example, the material of the protective cover 3 can be titanium alloy TC4, and the wall thickness of the protective cover 3 can be 0.8mm to 1.5mm. In actual situations, see Figure 1 As shown, along the axial extension direction of the nozzle, the protective cover 3 can be designed with a multi-section metal shell, which can be divided into 2 to 4 sections for easy installation, and a section of the metal shell near the inlet end can be produced by 3D printing technology, and the remaining metal shells can be processed by sheet metal technology, and the two adjacent sections of the metal shell can be connected by flanges. In addition, the metal shell can be hollowed out or topologically optimized to further reduce the weight of the nozzle, while saving material usage and saving the cost of the nozzle.
[0032] In a possible implementation, the material of the liner 1 is a ceramic-based composite material, so that the liner 1 has excellent properties such as high temperature resistance, high specific strength, high specific stiffness, low density, and ablation resistance, and can adapt to the working conditions of the engine. Specifically, the material of the liner 1 can be carbon fiber with silicon carbide deposited on the surface.
[0033] In some embodiments, the material of the outer lining 2 is a resin-based composite material, so that the outer lining 2 has the characteristics of lower density, good thermal insulation performance, high specific strength, short production cycle, and low manufacturing cost.
[0034] For example, the composite material matrix of the outer lining 2 may be phenolic resin, and the reinforcement of the outer lining may be quartz fiber, high silica fiber or carbon fiber. Of course, the invention is not limited thereto. Compared with the high temperature resistant ceramic matrix composite material used in the prior art, the cost is relatively low, which reduces the cost of the engine nozzle provided by the embodiment of the present invention.
[0035] As an optional method, the outer wall of the inner liner 1 and the inner wall of the outer liner 2 are bonded together through the transition layer 4. The inner liner 1 and the outer liner 2 are bonded together, which is simple and quick to operate and can shorten the production cycle of the nozzle. At the same time, the outer liner 2 can also be separated from the inner liner 1 by preheating and mechanical stripping, and is replaceable. In specific implementation, the transition layer 4 can be a carbon fiber cloth impregnated with phenolic resin. In this way, the transition layer 4 is a high temperature resistant bonding transition layer 4, which can bond the inner liner 1 and the outer liner 2.
[0036] In summary, compared with the prior art, the engine nozzle adopts an integral structure. When the nozzle is damaged and needs to be replaced, the entire nozzle needs to be replaced, which increases the use cost of the nozzle. The engine nozzle provided by the present application is split. When the outer liner 2 or the protective cover 3 is damaged and needs to be replaced, the damaged parts can be replaced separately, and the remaining undamaged parts do not need to be replaced, which can save the cost of the nozzle. In addition, the nozzle in the prior art adopts high-temperature resistant ceramic-based composite materials, while in the present application, only the material of the inner liner 1 adopts ceramic-based composite materials, and the material of the outer liner 2 can be phenolic resin-based composite materials. Compared with the prior art, the nozzle provided by the present application is cheap, which can reduce the use cost of the engine nozzle.
[0037] In a specific implementation, the ratio of the wall thickness of the inner liner 1, the wall thickness of the carbon fiber cloth impregnated with phenolic resin, and the wall thickness of the outer liner 2 is 1.5:1:3 to 2:1:3. For example, the ratio of the wall thickness of the inner liner 1, the wall thickness of the carbon fiber cloth impregnated with phenolic resin, and the wall thickness of the outer liner 2 can be 1.5:1:3, 1.6:1:3, 1.75:1:3, 1.8:1:3, 1.9:1:3, 2:1:3, etc.
[0038] In some embodiments, the wall thickness of the inner liner 1 and / or the wall thickness of the outer liner 2 gradually decreases from the inlet end to the outlet end. In order to reduce costs as much as possible, the wall thickness of the inner liner 1 of the nozzle can be appropriately reduced and the wall thickness of the outer liner 2 can be increased according to the gas parameters (temperature, pressure, etc.) at the inlet end of the nozzle and the working time. In addition, the static pressure of the gas on the inner wall of the nozzle gradually decreases along the nozzle, and the inner liner 1 of the nozzle can adopt a variable wall thickness design, that is, the wall thickness of the inner liner 1 is gradually reduced from the inlet end to the outlet end along the axis of the nozzle. Similarly, the outer liner 2 of the nozzle can adopt a variable wall thickness design, that is, the wall thickness of the outer liner 2 is gradually reduced from the inlet end to the outlet end along the axis of the nozzle.
[0039] The following describes a method for processing a nozzle provided in an embodiment of the present invention in a possible implementation manner. Of course, this is only an example and is not intended to be a specific limitation.
[0040] Step 1, making a lining 1 preform, obtaining a ceramic matrix composite lining 1 by chemical vapor deposition (CVI) and other processes; performing rough machining on the outer surface of the lining 1 to ensure the design size;
[0041] Step 2, using the lining 1 obtained in step 1 as the first core mold, using carbon fiber cloth impregnated with phenolic resin to make a transition layer 4 by winding method, and heating (150° C. to 175° C.) to cure;
[0042] Step 3, using the inner lining 1 obtained in step 2 and provided with a transition layer 4 as the second core mold, a composite material preform is manufactured by a winding method, a phenolic resin base is manufactured by a polycondensation reaction, and then the outer lining 2 is manufactured by hot pressing and curing, and finally the outer surface of the outer lining 2 is machined to ensure the assembly size;
[0043] Step 4, installing the metal shell in sections to provide a protective cover 3 outside the outer lining 2, thereby obtaining the nozzle provided in the embodiment of the present invention.
[0044] In addition to the above, an embodiment of the present invention further provides an engine, comprising a combustion chamber and the above-mentioned engine nozzle, wherein the inlet end of the engine nozzle is arranged at the outlet end of the combustion chamber. Specifically, the inner liner, outer liner, transition layer and one end of the protective cover of the engine nozzle close to the inlet end are installed on the combustion chamber.
[0045] The beneficial effects of the engine provided by the embodiment of the present invention can refer to the beneficial effects of the engine nozzle described in the first aspect, and will not be elaborated here.
[0046] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.
[0047] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.
Claims
1. An engine nozzle, It is characterized in that Having an inlet end and an outlet end connected to each other; the engine nozzle comprises: A liner having a cavity extending from the inlet end to the outlet end; An outer lining, sleeved outside the inner lining; The protective cover is sleeved outside the outer lining.
2. The engine nozzle according to claim 1, It is characterized in that The material of the lining is a ceramic-based composite material.
3. The engine nozzle according to claim 2, It is characterized in that The material of the lining is carbon fiber with silicon carbide deposited on the surface.
4. The engine nozzle according to claim 1, It is characterized in that The material of the outer lining is a resin-based composite material.
5. The engine nozzle according to claim 4, It is characterized in that The composite material matrix of the outer lining is phenolic resin, and the reinforcement of the outer lining is quartz fiber, high silica fiber or carbon fiber.
6. The engine nozzle according to claim 1, It is characterized in that The outer wall of the inner lining is bonded to the inner wall of the outer lining via a transition layer.
7. The engine nozzle according to claim 6, It is characterized in that The transition layer is a carbon fiber cloth impregnated with phenolic resin.
8. The engine nozzle according to claim 7, It is characterized in that The ratio of the wall thickness of the inner liner, the wall thickness of the carbon fiber cloth impregnated with phenolic resin, and the wall thickness of the outer liner is 1.5:1:3 to 2:1:
3.
9. The engine nozzle according to claim 1, It is characterized in that Along the direction from the inlet end to the outlet end, the wall thickness of the inner liner and / or the wall thickness of the outer liner gradually decreases.
10. An engine, It is characterized in that include: The engine nozzle according to any one of claims 1 to 9; The combustion chamber has an inlet end of the engine nozzle arranged at an outlet end of the combustion chamber.