Single-ended heat concentrated thermal disintegration optimized thermal protection cabin panel structure

Abstract

The application discloses a heat dissipation optimization heat protection cabin plate structure with single-end heat concentration, which comprises an ablation heat protection layer, a heat dissipation structure layer and a bearing heat insulation layer, wherein the ablation heat protection layer, the heat dissipation structure layer and the bearing heat insulation layer are all solid structures, are combined and fixedly installed in a mode of mechanical connection and glue joint, the ablation heat protection layer is located at the outermost layer of the cabin plate and faces the external thermal environment, and the ablation heat protection layer is made of an ablation-resistant composite material. In the application, the internal heat digestion capacity of the structure is enhanced, the heat dissipation layer is added to the structure, the heat concentration area of the ablation layer is uniformly and rapidly diffused, the overall average temperature of the structure is reduced, and the heat stress concentration is reduced. Compared with the existing heat protection structure, the structure of the application can more quickly solve the problem of high heat concentration at one end of the structure, and can reduce the load and thickness of the outermost heat protection layer.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat protection structure, and in particular to a heat dissipation optimized heat protection cabin panel structure for single-end heat concentration. BACKGROUND

[0002] In recent years, deep space exploration and space attack and defense have become the focus of attention of space powers worldwide. Among them, the heat protection of spacecraft return cabin, the high heat energy dissipation problem caused by attack and defense laser weapons and fine scratches has been an important content in spacecraft support at present and in the future. During the process of cabin reentry into the atmosphere and fine scratches that may occur during attack and defense, the spacecraft (or local) will experience very severe heat flow changes, so the rapid response heat dissipation capacity becomes a necessary basic condition for achieving mission reliability.

[0003] The current spacecraft heat protection structure is generally composed of an outer ablation layer and a load-bearing thermal insulation layer, which absorbs or carries away heat through the effects of pyrolysis, ablation, etc. of heat protection materials. The heat protection layer and the load-bearing structure layer are spliced and fixed by adhesive bonding, screwing and other forms. In actual situations, the short-time heat flow change experienced during reentry or attack and defense scratches is very severe, and local heat concentration is prone to occur. Therefore, the development of heat protection structures with good heat protection / insulation performance and rapid response heat dissipation capacity has become a necessary basic condition for achieving mission reliability. SUMMARY

[0004] The purpose of the present application is to solve the above problems and enhance the heat dissipation capacity of the structure. The structure increases a heat dissipation layer to make the heat concentration area of the ablation layer quickly and uniformly diffuse, reduce the overall average temperature of the structure and reduce thermal stress concentration, thereby providing a heat dissipation optimized heat protection cabin panel structure for single-end heat concentration.

[0005] In order to achieve the above purpose, the present application adopts the following technical scheme:

[0006] The heat dissipation optimized heat protection cabin panel structure for single-end heat concentration comprises an ablation heat protection layer, a heat dissipation structure layer and a load-bearing thermal insulation layer, all of which are solid structures and are combined and fixed by mechanical connection and adhesive bonding.

[0007] Preferably, the ablation heat protection layer is located at the outermost layer of the cabin panel and faces the external thermal environment, and is made of ablation-resistant composite material.

[0008] Preferably, the heat dissipation structure layer is an intermediate layer made of high thermal conductivity material combined with light weight and low density material.

[0009] Preferably, the force bearing and heat insulating layer is located at the innermost layer, facing the protected cabin inner structure, made of honeycomb material, and plays a mechanical support role.

[0010] Preferably, the mechanical connection adopts a high-temperature-resistant non-metal screw connection mode.

[0011] Preferably, the thermal delamination structure layer material is laid according to the optimization design result, and the optimization design process comprises the following steps:

[0012] S1, a structure model is established, and a heat exchange structure design area is determined;

[0013] S2, the regional heat conduction attribute is set, the heat conduction calculation formula is determined, the boundary condition of the definition domain is set, and the constraint conditions in the design area, i.e. the maximum temperature difference constraint and the volume fraction of two materials in the region, are added;

[0014] S3, a target function is set up, i.e. the average minimum in the region when the temperature field reaches a steady state, and the minimum maximum temperature difference in the region, and a mathematical model is given;

[0015] S4, a control equation is determined, i.e. a steady-state temperature balance equation;

[0016] S5, the design area and the non-design area in the definition domain are respectively divided into different density grids;

[0017] S6, the unit thermal conductivity is taken as a design variable, and the initial thermal conductivity of the unit in the design area is set;

[0018] S7, the heat flow density in the region is calculated;

[0019] S8, the unit efficiency is determined;

[0020] S9, the high-efficiency unit region material is replaced by a high-thermal-conductivity material;

[0021] S10, the design variable in the design area is iteratively calculated until the target function converges;

[0022] S11, a balanced temperature field distribution is given;

[0023] S12, the material distribution optimization shape calculation result is output.

[0024] As described above, due to the adoption of the above technical solutions, the present application has the following beneficial effects:

[0025] 1, The application makes the internal heat of the structure quickly digest the ability to enhance, the structure through increasing a layer of heat resolution layer, makes the heat concentration area of the ablation layer energy quickly and evenly spread, makes the overall average temperature of the structure drop and reduces the thermal stress concentration, compared with the existing heat protection structure, the structure of the application can more quickly resolve the problem of heat high concentration at one end of the structure, can reduce the load and thickness of the outermost heat protection layer. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The single-end heat concentration heat resolution optimization heat protection cabin panel ablation heat protection layer perspective view provided by the embodiment of the application is shown;

[0027] Figure 2 The heat resolution structure layer perspective view provided by the embodiment of the application is shown;

[0028] Figure 3 The load-bearing heat insulation layer perspective view provided by the embodiment of the application is shown;

[0029] Figure 4 The Figures 1-3 middle heat protection cabin panel a view is shown;

[0030] Figure 5 The Figures 1-3 middle heat protection cabin panel b / c view is shown;

[0031] Figure 6 The Figures 1-3 middle heat protection cabin panel d view is shown;

[0032] Figure 7 The Figure 2 middle heat protection cabin panel e section b view is shown;

[0033] Figure 8 The heat resolution structure material optimization design flow chart is shown.

[0034] Legend:

[0035] 1, Ablation heat protection layer; 2, Heat resolution structure layer; 3, Load-bearing heat insulation layer. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the application.

[0037] Please refer to Figures 1-8 , the application provides a technical solution:

[0038] The heat dissipation-optimized heat protection cabin panel structure is optimized by single-end heat concentration, and comprises an ablative heat protection layer 1, a heat dissipation structure layer 2 and a load-bearing heat insulation layer 3. The ablative heat protection layer 1, the heat dissipation structure layer 2 and the load-bearing heat insulation layer 3 are all solid structures, which are combined and fixed by mechanical connection and adhesive bonding. The mechanical connection adopts high-temperature-resistant non-metal screw connection. The layers are connected by SiC screws and supplemented by cured silicone adhesive.

[0039] Specifically, as shown in Figures 1-7 The ablative heat protection layer 1 is located at the outermost layer of the cabin panel and faces the external thermal environment, and is used to provide a heat protection boundary. The ablative heat protection layer 1 is made of ablative composite material.

[0040] The ablative heat protection layer 1 realizes efficient heat protection by physical processes of the material itself and chemical reactions with the environment gas, so as to avoid direct heat entering the cabin wall interior and protect the interior structure with relatively stable (or slowly rising) temperature. The layer is made of C / C-SiC material (C / C porous body prepared by CVI+PIC impregnation and carbonization densification of carbon fiber needle-punched preform, and C / C-SiC obtained by LSI reaction infiltration process on the C / C porous body), and the thickness is, for example, 3 mm.

[0041] The heat dissipation structure layer 2 is an intermediate layer made of high-thermal-conductivity material combined with lightweight and low-density material, which plays a role in rapidly dissipating and diffusing local heat. In the figure, the d direction is the heat concentration end, and the a direction is the end away from the heat source. The heat dissipation structure layer 2 plays a role in rapidly dissipating heat, reducing temperature difference in the region, and reducing average temperature in the region.

[0042] The load-bearing heat insulation layer 3 is located at the innermost layer and faces the protected cabin interior structure, and plays a role in supporting the cabin space structure. It is made of honeycomb material and plays a role in mechanical support.

[0043] The load-bearing heat insulation layer 3 plays a role in fixing the cabin panel configuration, bearing and heat insulation. For example, in the scenario of debris impact, the aircraft cabin panel needs to withstand the increasing or instantaneous internal and external pressure difference, while also trying to block the heat transferred from kinetic energy caused by friction to the cabin interior space. The material is very unfavorable for weight reduction of the spacecraft by thickening to strengthen its force / heat carrying capacity. The honeycomb structure has excellent mechanical properties and ultra-lightweight structure characteristics, so a phenolic foam filled and closed hexagonal glass steel honeycomb core material structure is adopted, so as to obtain good mechanical bearing capacity while enhancing the blocking ability of heat transfer to the structure interior. The thickness is, for example, 6 mm.

[0044] Specifically, as shown in Figure 8 The material of the heat dissipation structure layer 2 is arranged according to the optimization design result. The optimization design process comprises the following steps:

[0045] S1, establish a structure model, and determine a heat exchange structure design region;

[0046] S2, set a region heat conduction attribute, determine a heat conduction calculation formula, set a boundary condition of a definition domain, and add a constraint condition in the design region, that is, a maximum temperature difference constraint and a volume fraction of two materials in the region;

[0047] S3, set a target function, that is, the average minimum in the region when the temperature field reaches a steady state, and the minimum maximum temperature difference in the region, and give its mathematical model;

[0048] S4, determine the control equation, that is, the steady-state temperature balance equation;

[0049] S5, divide the design region and the non-design region in the definition domain into different density grids respectively;

[0050] S6, take the unit thermal conductivity as a design variable, and set the initial thermal conductivity of the unit in the design region;

[0051] S7, perform a heat flow density calculation in the region;

[0052] S8, determine the unit performance;

[0053] S9, replace the high-performance unit region material with a high thermal conductivity material;

[0054] S10, perform an iterative calculation on the design variable in the design region until the target function converges;

[0055] S11, give a balanced temperature field distribution;

[0056] S12, output the material distribution optimization shape calculation result.

[0057] The heat dissipation structure layer 2 is made of material A and material B, the material A is a high thermal conductivity material, for example, metal Gu; one end is in direct contact with the heat source, and the heat is quickly conducted and diffused along the A material distribution area through heat conduction; the material B is a low density material, which satisfies the lightweight filling support function of the layer, for example, Ti or AlSi10Mg. The layer is produced by integral forming additive manufacturing process, and the thickness is, for example, 2mm.

[0058] The heat dissipation protection wallboard structure designed in the application adds a heat dissipation structure layer 2 for the requirement of single-end heat concentration and rapid dissipation, which can quickly digest the thermal damage pressure caused by local heat concentration, improve the short-time heat digestion response capability, and reduce the overall balance temperature of the ablation layer, thereby reducing the thickness of the ablation layer and reducing the weight of the overall wallboard structure.

[0059] The foregoing description of the embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A single-ended heat concentrated thermally disassociated optimized thermal protection pod panel structure, characterized by, It comprises an ablation heat protection layer (1), a heat dissipation structure layer (2) and a load bearing heat insulation layer (3), all of which are solid structures and are combined and fixed by mechanical connection and glue jointing; The material of the heat dissipation structure layer (2) is given according to the optimization design, and the optimization design process comprises the following steps: S1, establishing a structure model and determining a heat exchange structure design region; S2, setting the region heat conduction attribute, determining the heat conduction calculation formula, setting the boundary condition of the definition domain, and adding the constraint conditions in the design region, i.e. the maximum temperature difference constraint and the volume fraction of two materials in the region; S3, setting the objective function, i.e. the average minimum in the region and the minimum maximum temperature difference in the region when the temperature field reaches a steady state, and giving the mathematical model thereof; S4, determining the control equation, i.e. the steady state temperature balance equation; S5, dividing the design region and the non-design region in the definition domain into grids with different densities respectively; S6, taking the unit thermal conductivity as the design variable and setting the initial thermal conductivity of the unit in the design region; S7, performing heat flow density calculation in the region; S8, judging the unit performance; S9, replacing the material in the high performance unit region with a high thermal conductivity material; S10, performing iterative calculation on the design variable in the design region until the objective function converges; S11, giving the balanced temperature field distribution; S12, outputting the material distribution optimization shape calculation result.

2. The single-ended heat concentrated thermal lysis optimized thermal protection cabin panel structure according to claim 1, wherein, The ablation heat protection layer (1) is located at the outermost layer of the cabin plate and faces the external thermal environment, and is made of ablation-resistant composite material.

3. The single-ended heat concentrated, thermally dissociated optimized thermal protection panel structure of claim 2, wherein, The heat dissipation structure layer (2) is an intermediate layer and is made of high thermal conductivity material in cooperation with light weight and low density material.

4. The single-ended heat concentrated, thermally dissociated optimized thermal protection panel structure of claim 3, wherein, The load bearing heat insulation layer (3) is located at the innermost layer and faces the protected cabin structure, is made of honeycomb material and plays a mechanical support role.

5. The single-ended heat concentrated, thermally dissociated optimized thermal protection panel structure of claim 4, wherein, The mechanical connection adopts high temperature resistant non-metal screw connection mode.

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