4D printed heat pipe leading edge structure

Abstract

The application belongs to the field of additive manufacturing design and manufacturing integration, and particularly relates to a 4D printed heat pipe type leading edge structure. The structure comprises a skin, which comprises an outer skin and an inner skin, the inner skin is arranged on the inner side of the outer skin, the outer skin and the inner skin have a containing cavity therebetween, the containing cavity contains liquid working medium, the inner surface of the outer skin and the inner surface of the inner skin are both provided with fine dot array structures; a plurality of partitions are arranged between the outer skin and the inner skin, and are used for separating the containing cavity, the partitions are provided with through holes, and the through holes are used for the flow of liquid working medium in adjacent containing cavities; a body connecting structure is arranged on the skin, and is used for connecting the skin and a body structure. The application can solve the problem of thermal protection of the leading edge structure of a hypersonic aircraft, and has the advantages of compact structure, high practicability and high reliability.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of additive manufacturing design and manufacturing integration, and particularly relates to a 4D printed heat pipe type leading edge structure. BACKGROUND

[0002] The gas friction at the stagnation point of the leading edge of a hypersonic aircraft produces strong aerodynamic heat, and the surface temperature can reach above 800 DEG C, which brings great pressure to the thermal protection requirements of the aircraft structure; meanwhile, different stages and postures during the flight of the aircraft can cause extreme temperature changes of the leading edge structure, which is easy to cause extreme changes of thermal stress of the structure, and further causes the destruction of the structure.

[0003] Therefore, it is desirable to have a technical solution to overcome or at least alleviate at least one of the aforementioned deficiencies of the prior art. SUMMARY

[0004] The application aims to provide a 4D printed heat pipe type leading edge structure to solve at least one problem existing in the prior art.

[0005] The technical solution of the application is:

[0006] A 4D printed heat pipe type leading edge structure has a wing leading edge shape, comprising:

[0007] A skin comprises an outer skin and an inner skin, the inner skin is arranged on the inner side of the outer skin, and the outer skin and the inner skin have a containing cavity therebetween, the containing cavity contains a liquid working medium, and the inner surface of the outer skin and the inner surface of the inner skin are both provided with a fine dot array structure;

[0008] A plurality of partitions are arranged between the outer skin and the inner skin, and are used to separate the containing cavities, and the partitions are provided with through holes for the flow of the liquid working medium in adjacent containing cavities;

[0009] A body connecting structure is mounted on the skin and is used to connect the skin and the body structure.

[0010] In at least one embodiment of the application, the liquid working medium is a sodium-potassium alloy.

[0011] In at least one embodiment of the application, the material of the fine dot array structure is a copper-based memory alloy.

[0012] In at least one embodiment of the application, the fine dot array structure comprises a plurality of fine units arranged in a dot array, and the fine unit comprises:

[0013] A first rectangular frame has a first connecting point, a second connecting point, a third connecting point and a fourth connecting point.

[0014] a second rectangular frame, the second rectangular frame is arranged in parallel with the first rectangular frame, the second rectangular frame has a fifth connecting point, a sixth connecting point, a seventh connecting point and an eighth connecting point, wherein the fifth connecting point is arranged opposite to the first connecting point, the sixth connecting point is arranged opposite to the second connecting point, the seventh connecting point is arranged opposite to the third connecting point, and the eighth connecting point is arranged opposite to the fourth connecting point;

[0015] a first connecting rod, the first connecting rod connects the first connecting point and the seventh connecting point;

[0016] a second connecting rod, the second connecting rod connects the second connecting point and the eighth connecting point;

[0017] a third connecting rod, the third connecting rod connects the third connecting point and the fifth connecting point;

[0018] a fourth connecting rod, the fourth connecting rod connects the fourth connecting point and the sixth connecting point;

[0019] a first screw rod, the first screw rod connects the first connecting point and the fifth connecting point;

[0020] a second screw rod, the second screw rod connects the second connecting point and the sixth connecting point;

[0021] a third screw rod, the third screw rod connects the third connecting point and the seventh connecting point;

[0022] a fourth screw rod, the fourth screw rod connects the fourth connecting point and the eighth connecting point.

[0023] In at least one embodiment of the present application, the partition plate includes a first partition plate and a second partition plate, wherein,

[0024] the first partition plate includes a plurality of first partition plates, the plurality of first partition plates are uniformly arranged along the span direction, and the plurality of first partition plates divide the accommodation cavity into a plurality of accommodation cavities along the span direction, and a through hole is formed in the first partition plate;

[0025] the second partition plate includes one second partition plate, and the second partition plate is arranged at the front end and divides the accommodation cavity into an upper accommodation cavity and a lower accommodation cavity.

[0026] In at least one embodiment of the present application, the through hole in the first partition plate is an oblong hole.

[0027] In at least one embodiment of the present application, the partition plate is provided with the fine point array structure at a position close to the outer skin.

[0028] In at least one embodiment of the present application, the outer skin, the inner skin, the fine and dense dot array structure and the partition plate are integrally formed structures using 4D printing technology.

[0029] The present application has at least the following beneficial technical effects:

[0030] The 4D printed heat pipe type leading edge structure of the present application can solve the thermal protection problem of the leading edge structure of a hypersonic aircraft, has the advantages of compact structure, strong practicability, high reliability, etc. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a schematic diagram of the 4D printed heat pipe type leading edge structure of an embodiment of the present application as a whole;

[0032] Figure 2 is a sectional view of the 4D printed heat pipe type leading edge structure of an embodiment of the present application;

[0033] Figure 3 is a schematic diagram of the outer skin of an embodiment of the present application;

[0034] Figure 4 is a schematic diagram of the inner skin of an embodiment of the present application;

[0035] Figure 5 is a schematic diagram of the fine and dense dot array structure of an embodiment of the present application;

[0036] Figure 6 is a schematic diagram of the partition plate of an embodiment of the present application.

[0037] Wherein:

[0038] 1-outer skin; 2-inner skin; 3-fine and dense dot array structure; 4-partition plate; 5-body connecting structure. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the embodiments of the present application will be described in more detail below in combination with the drawings of the embodiments of the present application. In the drawings, the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some of the embodiments of the present application, not all of the embodiments. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application. The embodiments of the present application will be described in detail below in combination with the drawings.

[0040] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limiting the scope of protection of this application.

[0041] The following is in conjunction with the appendix Figures 1 to 6 This application will be described in further detail.

[0042] This application provides a 4D printed heat pipe leading edge structure with a wing leading edge shape, including: skin, partition 4 and fuselage connection structure 5.

[0043] Specifically, such as Figure 2 As shown, the skin includes an outer skin 1 and an inner skin 2. The inner skin 2 is disposed inside the outer skin 1. There is a cavity between the outer skin 1 and the inner skin 2, which contains a liquid working medium. The inner surfaces of both the outer skin 1 and the inner skin 2 are provided with a fine dot matrix structure 3. Multiple partitions 4 are provided between the outer skin 1 and the inner skin 2. The partitions 4 are connected to the inner and outer skins respectively (no fine dot matrix structure 3 is provided at the connection between the inner and outer skins and the partitions 4). The partitions 4 can divide the cavity. Through holes are provided on the partitions 4 for the flow of liquid working medium in adjacent cavities. The body connection structure 5 is installed on the skin and is used to connect the skin to the body structure.

[0044] The city's 4D printed parts feature a heat pipe-type leading edge structure, and the liquid working fluid can be selected according to the actual working conditions of the leading edge. In the preferred embodiment of this application, the liquid working fluid is a sodium-potassium alloy.

[0045] In a preferred embodiment of this application, the fine dot matrix structure 3 is made of copper-based shape memory alloy. The fine dot matrix structure 3 includes multiple fine units arranged in a dot matrix pattern. Each fine unit includes two rectangular frames, four connecting rods, and four spiral rods. Specifically, the first rectangular frame has a first connecting point, a second connecting point, a third connecting point, and a fourth connecting point; the second rectangular frame is arranged parallel to the first rectangular frame and has a fifth connecting point, a sixth connecting point, a seventh connecting point, and an eighth connecting point. The fifth connecting point is opposite to the first connecting point, the sixth connecting point is opposite to the second connecting point, the seventh connecting point is opposite to the third connecting point, and the eighth connecting point is opposite to the fourth connecting point; the first connecting rod connects the first connecting point and the seventh connecting point; the second connecting rod connects the second connecting point and the eighth connecting point; the third connecting rod connects the third connecting point and the fifth connecting point; the fourth connecting rod connects the fourth connecting point and the sixth connecting point; the first spiral rod connects the first connecting point and the fifth connecting point; the second spiral rod connects the second connecting point and the sixth connecting point; the third spiral rod connects the third connecting point and the seventh connecting point; and the fourth spiral rod connects the fourth connecting point and the eighth connecting point.

[0046] In a preferred embodiment of this application, the partition 4 includes a first partition and a second partition. Multiple first partitions are evenly arranged along the longitudinal direction, dividing the receiving cavity into multiple sections. Multiple through holes are provided on the first partitions. In this embodiment, the through holes on the first partitions are preferably elongated elliptical holes. One second partition is located at the front end, dividing the receiving cavity into an upper receiving cavity and a lower receiving cavity. Advantageously, in this embodiment, a fine lattice structure 3 is also provided on the partition 4 near the outer skin 1, which, together with the fine lattice structures 3 on the outer skin 1 and the inner skin 2, constitutes a three-layer fine lattice structure 3.

[0047] The 4D printed part heat pipe leading edge structure of this application, such as Figure 3 As shown, the outer surface of the outer skin 1 is smooth, which structurally maintains the aerodynamic shape and bears the load, and functionally absorbs the aerodynamic heat of the leading edge outer surface, causing the working fluid to evaporate. The inner surface of the outer skin 1 is provided with a fine lattice structure 3, which can increase the skin stiffness and load-bearing capacity. At the same time, it uses the wetting effect of the relatively rough surface to absorb the liquid working fluid. Combined with the porous state of the fine lattice structure 3, it can absorb the liquid working fluid and promote the reflux of the liquid working fluid. The fine lattice structure 3 has a spiral connector in the height direction (the structure is similar to a spring). Utilizing the memory effect of the copper-based shape memory alloy, it shrinks at high temperature, further densifying the fine lattice structure 3, increasing the capillary force for liquid reflux, increasing the gas flow channel in the tube, and improving the thermal conductivity. At lower temperatures, the fine lattice structure 3 is relatively loose, reducing the resistance to liquid reflux.

[0048] The 4D printed part heat pipe leading edge structure of this application, such asFigure 4 As shown, the outer surface of the inner skin 2 is a smooth surface, which plays a role of bearing and connecting with the internal structure of the body in structure; the inner surface of the inner skin 2 is a fine lattice structure 3, which plays a role of absorbing liquid working medium and promoting the backflow of the liquid working medium, and forms a liquid working medium layer on the inner side of the inner skin 2, thereby playing a certain heat insulation role to avoid heat transfer to the inside of the body.

[0049] The 4D printed heat pipe type leading edge structure of the present application is integrally formed with the fine lattice structure 3 and the whole structure, which plays a role of bearing and increasing the structural rigidity in structure, and the inner and outer skins and the fine lattice structure 3 jointly play a role of absorbing liquid working medium and promoting the backflow of the liquid working medium in function, and also play a role of space division, thereby ensuring the uniformity of the distribution of the internal liquid working medium and high-temperature steam.

[0050] The 4D printed heat pipe type leading edge structure of the present application is integrally formed with the partition plate 4, which plays a role of bearing and can conduct the heat of the outer skin 1 to the inside to promote the evaporation of the working medium, plays a role of space division, and the openings on the partition plate 4 are long elliptical, which can realize printing without support, and can promote the convection of high-temperature steam to make the working medium distribute uniformly and promote the uniformity of temperature distribution without seriously reducing the bearing capacity.

[0051] The 4D printed heat pipe type leading edge structure of the present application is integrally formed with the partition plate 4, which plays a role of bearing and can conduct the heat of the outer skin 1 to the inside to promote the evaporation of the working medium, plays a role of space division, and the openings on the partition plate 4 are long elliptical, which can realize printing without support, and can promote the convection of high-temperature steam to make the working medium distribute uniformly and promote the uniformity of temperature distribution without seriously reducing the bearing capacity.

[0052] In the preferred embodiment of the present application, the outer skin 1, the inner skin 2, the fine lattice structure 3 and the partition plate 4 are integrally formed by using the 4D printing technology.

[0053] The 4D printed heat pipe type leading edge structure of the present application has the characteristics of modularity, simple structure and high reliability compared with the general leading edge structure, and can absorb a large amount of heat in a short time to realize rapid temperature control; compared with the combined split structure of the general heat pipe structure "shell (bearing, heat conduction) + wire mesh (liquid absorption, backflow)", the three layers of fine lattice structures 3 are arranged inside and integrally formed with the skin, which can effectively reduce the heat transfer to the inside; the fine lattice structure 3 plays a role of increasing the overall rigidity of the structure, and the fine lattice structure 3 has a near spring structure state in the height direction, which utilizes the memory effect of copper-based memory alloy, when the temperature rises, the spring gradually shrinks, further densifies the lattice, increases the liquid capillary force, increases the gas flow channel, improves the heat transfer efficiency, keeps the temperature of the leading edge structure relatively stable, avoids the thermal stress damage of the body structure caused by frequent extreme temperature changes; in the use process, a large amount of aerodynamic heat can be absorbed in a short time, the matching degree with the working condition at the stagnation point of the leading edge is high, and it can be applied on a hypersonic vehicle.

[0054] The heat pipe structure is a technology for transferring heat by using the phase change heat absorption principle of materials. The application can transfer a large amount of heat in a high temperature area to a low temperature area in a short time, thereby realizing the temperature reduction of the high temperature area, and has the advantages of fast response, high heat transfer power and the like. The patent is based on the 4D printing copper-based memory alloy forming technology. Based on the process constraints, the design and manufacture of the integrated heat pipe type leading edge structure are completed, the real-time change of the heat pipe efficiency with the temperature change is realized, the relative stability of the temperature of the leading edge structure is maintained, the service life is improved, and a new thermal protection technology scheme is formed.

[0055] The above is only a specific embodiment of the application, but the protection scope of the application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed in the application, which should be covered within the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A 4D printed heat pipe leading edge structure having an airfoil leading edge shape, characterized by, The application relates to a skin structure of a liquid metal heat pipe, which comprises the following parts: a skin structure, which comprises an outer skin (1) and an inner skin (2), the inner skin (2) is arranged on the inner side of the outer skin (1), the outer skin (1) and the inner skin (2) are provided with a containing cavity, the containing cavity contains liquid working medium, the inner surface of the outer skin (1) and the inner surface of the inner skin (2) are provided with fine lattice structures (3); a plurality of partitions (4) are arranged between the outer skin (1) and the inner skin (2) and are used for separating the containing cavities, the partitions (4) are provided with through holes, and the through holes are used for the flow of liquid working medium in adjacent containing cavities; a body connecting structure (5) is arranged on the skin structure and is used for connecting the skin structure and a body structure; the liquid working medium is sodium-potassium alloy; the material of the fine lattice structure (3) is copper-based memory alloy; the fine lattice structure (3) comprises a plurality of fine units arranged in a lattice, and the fine unit comprises: a first rectangular frame, which is provided with a first connecting point, a second connecting point, a third connecting point and a fourth connecting point; a second rectangular frame, which is arranged in parallel with the first rectangular frame and is provided with a fifth connecting point, a sixth connecting point, a seventh connecting point and an eighth connecting point, wherein the fifth connecting point is arranged opposite to the first connecting point, the sixth connecting point is arranged opposite to the second connecting point, the seventh connecting point is arranged opposite to the third connecting point, and the eighth connecting point is arranged opposite to the fourth connecting point; a first connecting rod, which connects the first connecting point and the seventh connecting point; a second connecting rod, which connects the second connecting point and the eighth connecting point; a third connecting rod, which connects the third connecting point and the fifth connecting point; a fourth connecting rod, which connects the fourth connecting point and the sixth connecting point; a first spiral rod, which connects the first connecting point and the fifth connecting point; a second spiral rod, which connects the second connecting point and the sixth connecting point; a third spiral rod, which connects the third connecting point and the seventh connecting point; a fourth spiral rod, which connects the fourth connecting point and the eighth connecting point.

2. The 4D printed heat pipe leading edge structure of claim 1, wherein, The partitions (4) comprise a first partition and a second partition, wherein the first partition comprises a plurality of first partitions, the first partitions are uniformly arranged along the span direction, the containing cavities are divided into a plurality of containing cavities along the span direction, and the first partitions are provided with through holes; the second partition comprises one second partition, which is arranged at the front end and divides the containing cavities into an upper containing cavity and a lower containing cavity.

3. The 4D-printed heat pipe leading edge structure of claim 2, wherein, The through holes on the first partition are long-elliptical holes.

4. The 4D-printed heat pipe leading edge structure of claim 3, wherein, The fine lattice structure (3) is arranged on the position close to the outer skin (1).

5. The 4D-printed heat pipe leading edge structure of claim 1, wherein, The outer skin (1), the inner skin (2), the fine lattice structure (3) and the partitions (4) are integrally formed by using 4D printing technology.

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