Thermal protection structure of aircraft

Abstract

The invention provides a thermal protection structure of an aircraft, and relates to the field of thermal protection structure design of ultra-high-speed aircrafts. The thermal protection structure comprises a rigid thermal insulation layer, a flexible thermal insulation layer, a thermal insulation layer and a heat conduction layer, the rigid thermal insulation layer comprises a plurality of thermal insulation tiles distributed side by side, and the thermal conductivity of the thermal insulation tiles is smaller than 3 W / m DEG C; the flexible heat insulation layer is arranged on the rigid heat insulation layer and covers the heat insulation tiles, and the heat conductivity of the flexible heat insulation layer is smaller than that of the heat insulation tiles; the heat insulation layer is arranged on the side, away from the rigid heat insulation layer, of the flexible heat insulation layer, and the heat conductivity of the heat insulation layer is smaller than that of the heat insulation tile; the heat conduction layer is arranged on the side, away from the rigid heat insulation layer, of the heat insulation layer, and the heat conductivity of the heat conduction layer is larger than that of the heat insulation tile. The thermal protection structure disclosed by the invention can perform thermal protection on key components.

Description

Technical Field

[0001] The present disclosure relates to the technical field of thermal protection structure design for hypersonic aircraft, and in particular to a thermal protection structure for an aircraft. Background Art

[0002] There are many technical challenges in the development of hypersonic vehicles. In particular, when flying through the atmosphere, key parts of the vehicle, such as the fairing, generate high temperatures due to friction with high-speed airflow. When in a high-temperature environment for a long time, key components may be damaged due to reduced strength and structural thermal deformation, which directly affects the structural safety and aerodynamic shape of the vehicle. Therefore, designing an effective thermal protection structure is the key to ensuring the safe flight of the vehicle.

[0003] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field. Summary of the invention

[0004] The present disclosure provides a thermal protection structure of an aircraft, which can provide thermal protection for key components.

[0005] According to one aspect of the present disclosure, there is provided a thermal protection structure of an aircraft, comprising:

[0006] A rigid thermal insulation layer, comprising a plurality of thermal insulation tiles arranged side by side, wherein the thermal conductivity of the thermal insulation tiles is less than 3W / m°C;

[0007] A flexible thermal insulation layer is provided on the rigid thermal insulation layer and covers each of the thermal insulation tiles, wherein the thermal conductivity of the flexible thermal insulation layer is less than the thermal conductivity of the thermal insulation tile;

[0008] A heat-insulating layer is provided on a side of the flexible heat-insulating layer away from the rigid heat-insulating layer, and the heat conductivity of the heat-insulating layer is less than the heat conductivity of the heat-insulating tile;

[0009] The heat-conducting layer is arranged on a side of the heat-insulating layer away from the rigid heat-insulating layer, and the heat conductivity of the heat-conducting layer is greater than the heat conductivity of the heat-insulating tile.

[0010] In an exemplary embodiment of the present disclosure, the thermal conductivity of the flexible thermal insulation layer is 0.04 W / m°C to 0.1 W / m°C.

[0011] In an exemplary embodiment of the present disclosure, the material of the thermal insulation tile is silicon carbide.

[0012] In an exemplary embodiment of the present disclosure, the flexible thermal insulation layer includes an extension portion and a plurality of convex strips connected to a surface of the extension portion away from the rigid thermal insulation layer; the thermal insulation layer has a plurality of grooves that are recessed inward in a direction perpendicular to the thermal insulation layer, and the convex strips are embedded in the grooves one by one.

[0013] In an exemplary embodiment of the present disclosure, the insulation layer includes a first insulation part and a second insulation part which are sequentially connected and alternately distributed, the thickness of the first insulation part is greater than the thickness of the second insulation part, and the groove is arranged in the first insulation part.

[0014] In an exemplary embodiment of the present disclosure, the thickness of the second thermal insulation part is greater than the thickness of the rigid thermal insulation layer, the thickness of the second thermal insulation part is greater than the thickness of the flexible thermal insulation layer, and the thickness of the second thermal insulation part is greater than the thickness of the thermal conductive layer.

[0015] In an exemplary embodiment of the present disclosure, the material of the thermal insulation layer is polyurethane foam.

[0016] In an exemplary embodiment of the present disclosure, the heat conductive layer conformally covers the surface of the heat insulating layer.

[0017] In an exemplary embodiment of the present disclosure, the thermal conductivity of the thermal conductive layer is greater than 110 W / m°C.

[0018] In an exemplary embodiment of the present disclosure, the material of the heat conductive layer includes carbon fiber or a carbon-based matrix.

[0019] The thermal protection structure of the aircraft disclosed in the present invention can isolate a large amount of heat through a rigid thermal insulation layer, a flexible thermal insulation layer, and a heat insulating layer to prevent a large amount of heat from entering the key components inside the thermal protection structure. At the same time, the small amount of heat that has entered can be diffused layer by layer through the rigid thermal insulation layer, the flexible thermal insulation layer, and the heat insulating layer, so that the heat transferred to the heat conductive layer is evenly dispersed. At this time, the heat will not be concentrated at a certain point, which can reduce the damage of the key components protected by the thermal protection structure caused by local high temperature; the heat can be quickly exported through the heat conductive layer, thereby reducing the damage of the heat to the key components that need to be protected. In addition, in the thermal protection structure, the stress in the rigid thermal insulation tile and the heat insulating layer can be released through the flexible thermal insulation layer to avoid stress concentration, reduce the probability of damage to the thermal protection structure, and increase the service life of the thermal protection structure.

[0020] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0022] Figure 1 It is a schematic diagram of the thermal protection structure of the aircraft in the embodiment of the present disclosure.

[0023] Figure 2 It is a three-dimensional diagram of the thermal protection structure of the aircraft in the embodiment of the present disclosure.

[0024] Figure 3 1 is a top view of the rigid thermal insulation layer in the embodiment of the present disclosure.

[0025] Figure 4 It is a left view of the rigid insulation layer in the embodiment of the present disclosure.

[0026] Figure 5 4 is a top view of the flexible thermal insulation layer in the embodiment of the present disclosure.

[0027] Figure 6 It is a left view of the flexible thermal insulation layer in the embodiment of the present disclosure.

[0028] Figure 7 1 is a top view of the thermal insulation layer in the embodiment of the present disclosure.

[0029] Figure 8 It is a left view of the insulation layer in the embodiment of the present disclosure.

[0030] Fig. 9 1 is a top view of the heat-conducting layer in the embodiment of the present disclosure.

[0031] Fig.10 It is a left view of the heat conducting layer in the embodiment of the present disclosure.

[0032] Fig.11 It is a test chart of thermal insulation performance of the thermal protection structure in the embodiment of the present disclosure and the traditional thermal protection structure.

[0033] In the figure: 1, rigid insulation layer; 11, insulation tile; 2, flexible insulation layer; 21, extension part; 22, convex strip; 3, insulation layer; 31, first insulation part; 32, second insulation part; 301, groove; 4, heat conductive layer. DETAILED DESCRIPTION

[0034] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be comprehensive and complete and will fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted.

[0035] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of the illustration to another component, these terms are used in this specification only for convenience, such as according to the orientation of the examples described in the drawings. It is understood that if the device of the illustration is turned upside down, the component described as "upper" will become the component "lower". When a structure is "on" other structures, it may mean that the structure is formed integrally on the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure through another structure.

[0036] The terms "a", "an", "the" and "said" are used to indicate the presence of one or more elements / components / etc.; the terms "including" and "having" are used to indicate an open-ended inclusive meaning and mean that there may be additional elements / components / etc. in addition to the listed elements / components / etc. The terms "first" and "second" are used only as labels and are not intended to limit the quantity of their objects.

[0037] At super-Mach speeds, the aerodynamic thermal environment faced by the aircraft is extremely harsh. When the aircraft passes through the atmosphere, the air molecules are quickly squeezed in front of the aircraft, forming an extremely high-pressure area. At the same time, because the flight speed exceeds the speed of sound, the air molecules form strong compression and friction on the surface of the aircraft, causing the air temperature to rise sharply. This aerodynamic heating effect causes the surface temperature of the aircraft to rise sharply, which may reach more than thousands of degrees Celsius, posing a great challenge to the structural strength of the aircraft. Therefore, designing an effective thermal protection structure is the key to ensuring the safe flight of the aircraft.

[0038] In recent years, a variety of thermal protection structures have been developed to meet different needs and application scenarios, including passive thermal protection and active thermal protection. Passive thermal protection relies on the material and structure itself to absorb and radiate heat. It is simple and reliable, but increases the weight of the aircraft and is suitable for short-term work and medium heat flow. Active thermal protection uses coolant and forced convection to remove heat, reduce material mass, increase payload and range, but requires additional energy drive and increases system complexity.

[0039] Based on this, the embodiment of the present disclosure provides a thermal protection structure of an aircraft, such as Figure 1 and Figure 2As shown, the heat protection structure may include a rigid heat insulation layer 1, a flexible heat insulation layer 2, a heat insulating layer 3 and a heat conducting layer 4, wherein:

[0040] The rigid heat-insulating layer 1 comprises a plurality of heat-insulating tiles 11 arranged side by side, and the heat conductivity of the heat-insulating tiles 11 is less than 3W / m°C;

[0041] The flexible thermal insulation layer 2 is arranged on the rigid thermal insulation layer 1 and covers each thermal insulation tile 11, and the thermal conductivity of the flexible thermal insulation layer 2 is less than the thermal conductivity of the thermal insulation tile 11;

[0042] The heat insulating layer 3 is arranged on a side of the flexible heat insulating layer 2 away from the rigid heat insulating layer 1, and the heat conductivity of the heat insulating layer 3 is less than the heat conductivity of the heat insulating tile 11;

[0043] The heat-conducting layer 4 is disposed on a side of the heat-insulating layer 3 away from the rigid heat-insulating layer 1 , and the heat conductivity of the heat-conducting layer 4 is greater than the heat conductivity of the heat-insulating tile 11 .

[0044] The thermal protection structure of the aircraft disclosed in the present invention can isolate a large amount of heat through the rigid thermal insulation layer 1, the flexible thermal insulation layer 2, and the thermal insulation layer 3 to prevent a large amount of heat from entering the key components inside the thermal protection structure. At the same time, the small amount of heat that has entered can be diffused layer by layer through the rigid thermal insulation layer 1, the flexible thermal insulation layer 2, and the thermal insulation layer 3, so that the heat transferred to the thermal conductive layer 4 is evenly dispersed. At this time, the heat will not be concentrated at a certain point, which can reduce the damage of the key components protected by the thermal protection structure caused by local high temperature; the heat can be quickly exported through the thermal conductive layer 4, thereby reducing the damage of the heat to the key components that need to be protected. In addition, in the thermal protection structure, the stress in the rigid thermal insulation tile 11 and the thermal insulation layer 3 can be released through the flexible thermal insulation tile 11 to avoid stress concentration, reduce the probability of damage to the thermal protection structure, and increase the service life of the thermal protection structure.

[0045] The following is a detailed description of the various parts and specific details of the thermal protection structure of the aircraft disclosed in the present invention:

[0046] like Figure 3 and Figure 4 As shown, the rigid thermal insulation layer 1 may include a plurality of thermal insulation tiles 11 arranged side by side, and each thermal insulation tile 11 may be arranged at intervals, that is, there is a gap between adjacent thermal insulation tiles 11. This design can reduce direct contact between the thermal insulation tiles 11, reduce the efficiency of heat conduction, and effectively disperse the thermal stress caused by temperature changes, reducing the risk of cracking of the thermal insulation tiles 11. At the same time, the interval distribution also provides convenience for subsequent maintenance or replacement of a single thermal insulation tile 11.

[0047] In an exemplary embodiment of the present disclosure, the insulation tiles 11 can be arranged in an array, and the position of each insulation tile 11 is precisely arranged according to a predetermined geometric pattern (such as a rectangle, a hexagon, etc.). This regularity is not only beautiful, but more importantly, it can ensure the overall uniformity of the insulation layer, avoid excessive accumulation of heat in local areas, and thus improve the consistency of the insulation effect in different areas.

[0048] In an exemplary embodiment of the present disclosure, the number of thermal insulation tiles 11 may be 12, and the 12 thermal insulation tiles 11 may be arranged in rows and columns. For example, the 12 thermal insulation tiles 11 may be distributed in four rows and three columns, and the spacing between different columns may be equal, and the spacing between different rows may also be equal; the row spacing and column spacing may be equal or unequal, and the row spacing and column spacing may be adjusted specifically according to the direction of thermal stress. For example, when the thermal stress in the row direction is larger and the thermal stress in the column direction is smaller, the row spacing may be set to be larger than the column spacing; for example, when the thermal stress in the column direction is larger and the thermal stress in the row direction is smaller, the column spacing may be set to be larger than the row spacing.

[0049] The material of the thermal insulation tile 11 may be a material with a relatively low thermal conductivity. For example, the thermal conductivity of the thermal insulation tile 11 may be less than 3W / m°C. The lower thermal conductivity can isolate a large amount of heat from entering the body, and can effectively prevent the conduction of high-temperature fluids. For example, the material of the thermal insulation tile 11 may be silicon carbide (whose thermal conductivity is 2.837W / m°C). This material has the characteristics of high temperature resistance, light weight, high strength, and corrosion resistance. It can reduce the weight of the structure while ensuring the thermal insulation performance, and improve the overall stability and durability. In addition, the thermal insulation tile 11 can also block or reflect part of the thermal radiation, which can further reduce the impact of heat on key components inside the thermal protection structure.

[0050] The thermal conductivity of the flexible thermal insulation layer 2 is less than the thermal conductivity of the thermal insulation tile 11. For example, the thermal conductivity of the flexible thermal insulation layer 2 may be 0.04W / m°C to 0.1W / m°C. For example, the thermal conductivity of the flexible thermal insulation tile 11 may be 0.04W / m°C, 0.06W / m°C, 0.08W / m°C or 0.1W / m°C. Of course, the thermal conductivity of the flexible thermal insulation layer 2 may also be other values, which are not listed here one by one.

[0051] In an exemplary embodiment of the present disclosure, the material of the flexible thermal insulation layer 2 may be thermal insulation fiber (e.g., II-XS-Z-1 fiber flexible thermal insulation felt). In a high temperature environment, the II-XS-Z-1 fiber can maintain the stability of its structure and will not experience significant performance degradation due to temperature increase. At the same time, the thermal insulation fiber also has good resistance to a variety of chemical substances and can maintain a long-term stable thermal insulation effect in a complex environment.

[0052] Please continue to see Figure 1 and Figure 2As shown, the flexible thermal insulation layer 2 can be provided on the rigid thermal insulation layer 1, and can cover each thermal insulation tile 11. The flexible thermal insulation layer 2 can be fixed on the thermal insulation tile 11 in the rigid thermal insulation layer 1 by bonding. For example, the flexible thermal insulation layer 2 can be bonded to the rigid thermal insulation layer 1 by a two-component modified epoxy adhesive (model: DG-3S; manufacturer: Zhonglan Chenguang). The heat passing through the rigid thermal insulation layer 1 can enter the flexible thermal insulation layer 2, and in the process of interlayer transfer, the heat is dispersed layer by layer by the rigid thermal insulation layer 1 and the flexible thermal insulation layer 2, thereby avoiding heat concentration. At the same time, the stress in the rigid thermal insulation tile 11 can be released through the flexible thermal insulation layer 2 to avoid stress concentration, thereby reducing the probability of damage to the thermal protection structure and increasing the service life of the thermal protection structure.

[0053] In an exemplary embodiment of the present disclosure, Figure 5 and Figure 6 As shown, the flexible thermal insulation layer 2 may include an extension portion 21 and a plurality of convex strips 22 connected to the surface of the extension portion 21 away from the rigid thermal insulation layer 1. The extension portion 21 may be in the form of a sheet and may extend in a direction parallel to the thermal insulation tile 11, and the convex strips 22 may also be in the form of a sheet and may be distributed perpendicularly to the extension portion 21. The plurality of convex strips 22 may be arranged at intervals and arranged in parallel. In an exemplary embodiment of the present disclosure, the extension portion 21 and the convex strips 22 may be an integrated structure.

[0054] Please continue to see Figure 1 and Figure 2 As shown, the insulation layer 3 can be arranged on the side of the flexible insulation layer 2 away from the rigid insulation layer 1, and the thermal conductivity of the insulation layer 3 is less than the thermal conductivity of the insulation tile 11. For example, the thermal conductivity of the insulation layer 3 can be 0.05W / m℃. A large amount of heat can be isolated by the rigid insulation layer 1, the flexible insulation layer 2, and the insulation layer 3 to prevent a large amount of heat from entering the key components inside the thermal protection structure. At the same time, the small amount of heat that has entered can be diffused layer by layer through the rigid insulation layer 1, the flexible insulation layer 2, and the insulation layer 3, which can greatly improve the uniformity of heat dispersion. In the present disclosure, the insulation layer 3 can be in contact with the flexible insulation layer 2, and the stress in the insulation layer 3 can be released through the flexible insulation layer 2, which can avoid stress concentration, thereby further reducing the probability of damage to the thermal protection structure and improving the service life of the thermal protection structure.

[0055] In an exemplary embodiment of the present disclosure, Figure 7 and Figure 8As shown, the insulation layer 3 has a plurality of grooves 301 that are recessed inward in a direction perpendicular to the insulation layer 3. The grooves 301 may be strip-shaped and may extend in a direction parallel to the insulation tile 11. The size of the grooves 301 matches the size of the convex strips 22 in the flexible insulation layer 2, and the convex strips 22 may be embedded in each groove 301 one by one. In this process, the convex strips 22 on the flexible insulation layer 2 cooperate with the grooves 301 in the insulation layer 3, thereby achieving a tight fitting connection between the flexible insulation layer 2 and the insulation layer 3. This connection method not only ensures good contact between the insulation layer 3 and the flexible insulation layer 2, reduces the gap for heat transfer, but also provides additional mechanical support through the fitting of the convex strips 22 and the grooves 301, thereby enhancing the stability of the entire insulation structure. In addition, this connection method is also convenient for construction, and can quickly achieve precise docking of the insulation layer 3 and the flexible insulation layer 2.

[0056] At the same time, since the insulation layer 3 and the flexible insulation layer 2 are connected in a chimeric manner, the contact area between the flexible insulation layer 2 and the insulation layer 3 is increased. Since the flexible insulation layer 2 has a certain elasticity, it can effectively release the stress caused by temperature changes, external pressure and other factors. Especially in a high temperature environment, the thermal protection structure may be deformed due to thermal expansion and contraction. The chimeric connection method can allow a certain displacement and deformation, thereby avoiding structural damage caused by stress concentration. At the same time, the chimeric connection between the convex strip 22 and the groove 301 can also disperse the stress, so that the stress is evenly distributed in the insulation structure, which can improve the durability and reliability of the thermal protection structure.

[0057] In an exemplary embodiment of the present disclosure, please continue to refer to Figure 7 and Figure 8 The heat insulating layer 3 may include a first heat insulating portion 31 and a second heat insulating portion 32 which are sequentially connected and alternately distributed in a direction parallel to the heat insulating tile 11, and the first heat insulating portion 31 and the second heat insulating portion 32 may be an integrated structure. The thickness of the first heat insulating portion 31 may be greater than the thickness of the second heat insulating portion 32, so that the surface of the heat insulating layer 3 away from the flexible heat insulating layer 2 presents an uneven shape.

[0058] In an exemplary embodiment of the present disclosure, the groove 301 can be provided in the first heat insulating part 31, and the depth of the groove 301 is less than half of the thickness of the first heat insulating part 31. Since the thickness of the first heat insulating part 31 is relatively large, it is not easy to generate cracks by providing the groove 301 in the first heat insulating part 31, which helps to improve the service life of the thermal protection structure. The thickness of the second heat insulating part 32 is greater than the thickness of the rigid heat insulating layer 1; the thickness of the second heat insulating part 32 is greater than the thickness of the flexible heat insulating layer 2; at the same time, the thickness of the second heat insulating part 32 is greater than the thickness of the heat conductive layer 4.

[0059] In some embodiments of the present disclosure, the material of the thermal insulation layer 3 may be a light material, which helps to reduce the weight of the aircraft and improve fuel efficiency. At the same time, the material of the thermal insulation layer 3 is a material with good thermal insulation performance, which can isolate heat to a certain extent. For example, the material of the thermal insulation layer 3 may be polyurethane foam, which has extremely low thermal conductivity and can effectively prevent the transfer of heat. At the same time, it also has the characteristics of light weight and high strength, so that the thermal insulation layer 3 will not bring too much burden to the entire structure while maintaining good thermal insulation performance. In addition, polyurethane foam also has good chemical corrosion resistance and anti-aging performance, and can maintain stable performance in harsh environments.

[0060] It should be noted that the heat insulating layer 3 (made of polyurethane foam) in the present disclosure is not in direct contact with the outermost rigid heat insulating layer 1, and thus will not be affected by the relatively high heat in the rigid heat insulating layer 1, and its structural stability is relatively strong.

[0061] Please continue to see Figure 1 and Figure 2 As shown, the heat-conducting layer 4 can be arranged on the side of the heat-insulating layer 3 away from the rigid heat-insulating layer 1. For example, the heat-conducting layer 4 can cover the surface of the heat-insulating layer 3 in a conformal manner. Fig. 9 and Fig.10 As shown, when the surface of the thermal insulation layer 3 is an uneven surface, the contact area between the thermal conductive layer 4 and the thermal insulation layer 3 is relatively large, which can reduce stress concentration; at the same time, the thermal resistance between the thermal insulation layer 3 and the thermal conductive layer 4 can be reduced, and the heat transfer rate of the thermal conductive layer 4 is faster.

[0062] It should be noted that the surface shape and size of the heat insulating layer 3 away from the heat insulating tile 11 match the surface shape and size of the key component protected by the heat protection structure, so as to facilitate the subsequent configuration of the heat protection structure on the key component. That is, the shape and size of the surface of the heat conductive layer 4 can be changed according to the shape and size of the key component, that is, the surface shape of the heat conductive layer 4 can also be other shapes, which are not specifically limited here.

[0063] The thermal conductivity of the heat-conducting layer 4 is greater than the thermal conductivity of the thermal insulation tile 11. For example, the thermal conductivity of the heat-conducting layer 4 may be greater than 110W / m℃, and the heat can be quickly discharged through the heat-conducting layer 4 to keep the temperature of the aircraft within a controllable range, effectively protect the aircraft from high temperature and other external environmental influences, and reduce the damage of heat to key components that need to be protected. At the same time, the material of the heat-conducting layer 4 may be a material with a certain rigidity. For example, the material of the heat-conducting layer 4 may include carbon fiber or a carbon-based matrix (with a thermal conductivity of 117W / m℃). Carbon fiber or a carbon-based matrix can support and protect the thermal protection structure while reducing the mass of the aircraft due to its high strength and light weight.

[0064] The following article compares the thermal protection performance of the new conductive thermal protection structure (i.e., the thermal protection structure in this application) with that of the traditional conductive thermal protection structure through simulation analysis. Fig.11 The thermal insulation performance test graph of the new thermal protection structure and the traditional thermal protection structure is shown. It can be seen that at 400°C, the thermal insulation effect of the new thermal protection structure and the traditional thermal protection structure is not much different, but as the aircraft re-enters the atmosphere, the temperature will rise rapidly, and the cold surface temperature of the traditional thermal protection structure will rise sharply. On the other hand, in the process of rapid temperature rise, the new dredging thermal protection structure can quickly transfer heat from the high temperature area (i.e., the thermal conductive layer) to the low temperature area in a short time, avoiding the damage and deformation of the aircraft structure strength caused by the rapid rise in high temperature, which shows that the new dredging thermal protection structure has more efficient characteristics in terms of thermal insulation performance. This means that under the same heat flow conditions, the new dredging thermal protection structure can more effectively reduce the rise in internal temperature and provide more reliable thermal protection. This is attributed to the fact that the new dredging thermal protection structure adopts a series of designs of layer-by-layer thermal insulation and heat diffusion to evenly distribute the heat in the thermal conductive layer 4, and quickly extracts the heat through the thermal conductive layer 4 with high thermal conductivity, thereby improving the thermal insulation performance of the thermal protection structure. These improvements include optimized heat transfer paths, more efficient insulation materials, or more sophisticated structural designs. Therefore, the thermal protection structure in this application can provide more reliable protection when facing high temperature environments or other thermal stresses, reducing the risk of thermal damage to the system or equipment.

[0065] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the invention disclosed herein. This application is intended to cover any modification, use or adaptation of the present disclosure, which follows the general principles of the present disclosure and includes common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present disclosure are indicated by the appended claims.

Claims

1. A thermal protection structure for an aircraft, characterized in that: include: A rigid thermal insulation layer, comprising a plurality of thermal insulation tiles arranged side by side, wherein the thermal conductivity of the thermal insulation tiles is less than 3W / m°C; A flexible thermal insulation layer is provided on the rigid thermal insulation layer and covers each of the thermal insulation tiles, wherein the thermal conductivity of the flexible thermal insulation layer is less than the thermal conductivity of the thermal insulation tile; A heat-insulating layer is provided on a side of the flexible heat-insulating layer away from the rigid heat-insulating layer, and the heat conductivity of the heat-insulating layer is less than the heat conductivity of the heat-insulating tile; The heat-conducting layer is arranged on a side of the heat-insulating layer away from the rigid heat-insulating layer, and the heat conductivity of the heat-conducting layer is greater than the heat conductivity of the heat-insulating tile.

2. The heat protection structure according to claim 1, characterized in that: The thermal conductivity of the flexible heat-insulating layer is 0.04W / m°C to 0.1W / m°C.

3. The heat protection structure according to claim 1, characterized in that: The material of the thermal insulation tile is silicon carbide.

4. The heat protection structure according to claim 1, characterized in that: The flexible thermal insulation layer includes an extension portion and a plurality of convex strips connected to a surface of the extension portion away from the rigid thermal insulation layer; the thermal insulation layer has a plurality of grooves that are recessed inward in a direction perpendicular to the thermal insulation layer, and the convex strips are embedded in the grooves one by one.

5. The heat protection structure according to claim 4, characterized in that: The heat-insulating layer includes a first heat-insulating portion and a second heat-insulating portion which are sequentially connected and alternately distributed. The thickness of the first heat-insulating portion is greater than the thickness of the second heat-insulating portion. The groove is disposed in the first heat-insulating portion.

6. The heat protection structure according to claim 5, characterized in that: The thickness of the second heat insulating portion is greater than the thickness of the rigid heat insulating layer, the thickness of the second heat insulating portion is greater than the thickness of the flexible heat insulating layer, and the thickness of the second heat insulating portion is greater than the thickness of the heat conductive layer.

7. The heat protection structure according to any one of claims 1 to 6, characterized in that: The material of the heat insulation layer is polyurethane foam.

8. The heat protection structure according to any one of claims 1 to 6, characterized in that: The heat conductive layer conformally covers the surface of the heat insulating layer.

9. The heat protection structure according to claim 8, characterized in that: The thermal conductivity of the thermal conductive layer is greater than 110 W / m°C.

10. The heat protection structure according to claim 8, characterized in that: The material of the heat conducting layer includes carbon fiber or a carbon-based matrix.

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