A gas phase sweating cooling thermal protection system based on self-sustaining channel supply

Abstract

The present invention discloses a gas-phase transpiration cooling thermal protection system based on self-sustaining channel supply, which includes a gas source supply device and a gas-phase transpiration cooling thermal protection device; the gas source supply device includes a self-sustaining channel, a gas storage tank, a regenerative cooling channel and a spray cooling assembly, and the gas-phase transpiration cooling thermal protection device includes a porous medium layer and a coolant supply channel; the self-sustaining channel includes a front section and a rear section, which are used to inhale the high-speed oncoming flow and transport it to the gas storage tank; the regenerative cooling channel is arranged around the front section to cool the high-speed oncoming flow for the first time; the spray cooling assembly includes a plurality of spray coolers arranged in the rear section to cool the high-speed oncoming flow for the second time; the porous medium layer is arranged on the outer surface of the aircraft. The present invention is applied to the field of high-speed aircraft thermal protection technology, greatly reducing the mass of the coolant that the aircraft needs to carry, and improving the endurance of the aircraft while ensuring the cooling efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of thermal protection for high-speed aircraft, and specifically to a gas-phase transpiration cooling thermal protection system based on self-sustaining channel supply. Background Art

[0002] High-speed aircraft (Ma≥5) play a crucial role in modern aerospace fields, and have inestimable strategic value for scientific exploration and future space development, etc. With the continuous progress of technology, high-speed aircraft are continuously moving towards the goals of higher speed, longer flight time, and more complex tasks. However, this also causes the aircraft surface to bear extreme thermal loads and suffer strong aerodynamic drag, which poses severe challenges to its material selection, structural design, and thermal protection system.

[0003] For example, when the aircraft flies in the atmosphere at a Mach number of 10, the aerodynamic heating at the leading edge of the nose cone can cause the total temperature to rise to about 3900K, while the combustion heating inside the engine makes the working temperature exceed 3000K. Traditional passive thermal protection technologies, such as heat insulation, heat sink, and radiation heat dissipation, although they can also provide certain thermal protection, have gradually shown their limitations when facing the increasing performance requirements of high-speed aircraft. Therefore, the current research focus must shift to more efficient and reliable active thermal protection technologies to cope with the extreme thermal environment encountered during high-speed flight, and provide higher limit cooling capacity and longer-term stable thermal protection for the aircraft. Summary of the Invention

[0004] Aiming at the deficiencies in the above-mentioned prior art, the present invention provides a gas-phase transpiration cooling thermal protection system based on self-sustaining channel supply, which realizes efficient thermal management of key areas and the whole of high-speed aircraft, and reduces the aerodynamic drag encountered in extreme environments to a certain extent. It can not only cope with the harsh thermal environment during high-speed flight, but also effectively improve the aerodynamic performance and flight efficiency of the aircraft, and meet the thermal protection requirements for high-speed, long-time, and long-distance flight of the aircraft in the atmosphere.

[0005] To achieve the above object, the present invention provides a gas-phase transpiration cooling thermal protection system based on self-sustaining channel supply, including a gas source supply device and a gas-phase transpiration cooling thermal protection device;

[0006] The gas source supply device includes a self-sustaining channel arranged inside the aircraft, a gas storage tank, a regenerative cooling channel, and a spray cooling assembly, and the gas-phase transpiration cooling thermal protection device includes a porous medium layer and a cooling working medium supply channel;

[0007] The self-sustaining channel includes a front section and a rear section. The first end of the front section is open and located at the head of the aircraft. The first end of the rear section is connected to the second end of the front section, and the second end of the rear section is connected to the gas storage tank for inhaling high-speed oncoming flow and delivering it to the gas storage tank.

[0008] The regenerative cooling channel is arranged around the front section to perform regenerative cooling using cryogenic fuel to achieve the first temperature reduction of the high-speed oncoming flow. The spray cooling assembly includes a plurality of spray coolers arranged in the rear section for performing the second temperature reduction of the high-speed oncoming flow.

[0009] The porous medium layer is arranged on the outer surface of the aircraft. One end of the cooling working medium supply channel is connected to the gas storage tank, and the other end extends to the inner surface of the porous medium layer. An opening communicating with the inner surface of the porous medium layer is provided on the cooling working medium supply channel.

[0010] In one embodiment, the spray cooling assembly further includes a water storage tank, a water supply pipeline, and a gas supply pipeline. One end of the water supply pipeline is connected to the water storage tank, and the other end is respectively connected to each spray cooler. One end of the gas supply pipeline is connected to the gas storage tank, and the other end is respectively connected to each spray cooler.

[0011] In one embodiment, the water supply pipeline includes a main water supply path and a plurality of water supply branches, and each water supply branch corresponds to a spray cooler. The first end of the main water supply path is connected to the water storage tank, the first end of each water supply branch is connected to the second end of the main water supply path, the second end of each water supply branch is respectively connected to the corresponding spray cooler, a first check valve and a waterway solenoid valve are provided on the main water supply path, and a first flow valve is provided on each water supply branch.

[0012] The gas supply pipeline includes a main gas supply path and a plurality of gas supply branches, and each gas supply branch corresponds to a spray cooler. The first end of the main gas supply path is connected to the gas storage tank, the first end of each gas supply branch is connected to the second end of the main gas supply path, the second end of each gas supply branch is respectively connected to the corresponding spray cooler, a second check valve, a gas path solenoid valve, and a pressure regulating valve are provided on the main gas supply path, and a second flow valve is provided on each gas supply branch.

[0013] In one embodiment, the spray coolers appear in pairs in the rear section and are spaced apart along the gas flow direction. The two spray coolers in a pair are symmetrically arranged on the channel wall of the rear section, and any one of the spray coolers is located within the spray field of the other spray cooler.

[0014] In one embodiment, the spacing between adjacent pairs of the spray coolers gradually increases along the flow direction of the gas.

[0015] In one embodiment, temperature sensors are provided on the channel wall of the rear section part and at positions corresponding to the downstream of each pair of the spray coolers, and the detection surface of the temperature sensor is flush with the channel wall of the rear section part.

[0016] In one embodiment, the regenerative cooling channel is a spiral flow channel coiled around the outer wall of the front section part.

[0017] In one embodiment, a third flow valve is provided in the coolant supply channel.

[0018] In one embodiment, the porosity of the porous medium layer is 10% - 70% and the thickness is 2 - 20 mm.

[0019] Compared with the prior art, the present invention has the following beneficial technical effects:

[0020] 1. The present invention utilizes the high-temperature and high-pressure oncoming flow after introducing the bow shock wave through the self-sustaining channel, and through a unique secondary cooling design and the natural pressurization mechanism of the gas storage tank, realizes the stable delivery of the gaseous coolant. Compared with the traditional transpiration cooling system that often relies on a large amount of coolant to meet the thermal protection requirements, the present invention greatly reduces the mass of the coolant that the aircraft needs to carry, and improves the endurance of the aircraft while ensuring the cooling efficiency;

[0021] 2. The present invention utilizes the natural pressurization of the gas storage tank to provide a stable driving pressure for the coolants of the spray cooling and transpiration cooling, enabling the gas storage tank to not only serve as the storage and delivery unit of the cooling medium, but also provide power for the spray cooler through its natural pressurization characteristics, realizing the integrated supply of the cooling medium and power. In addition, the need for pumping the coolant is eliminated, which not only greatly reduces the overall load of the aircraft, improves the flight performance, but also enhances the overall reliability of the system and the simplicity of maintenance;

[0022] 3. In the preferred embodiment of the present invention, by symmetrically arranging the spray coolers, the gas temperature around the spray cooler is effectively prevented from being too high, thereby improving the service life of the spray cooler and reducing the maintenance cost;

[0023] 4. In the preferred embodiment of the present invention, by arranging temperature sensors in the rear section part, the cooling effect of the high-temperature and high-pressure oncoming flow can be monitored in real time, and then the spray amount of each spray cooler can be adjusted in real time. Description of the Drawings

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0025] Figure 1 It is a schematic diagram of the principle of the gas-phase transpiration cooling thermal protection system in the embodiment of the present invention;

[0026] Figure 2 It is a schematic diagram of the principle of the gas-phase transpiration cooling thermal protection device in the embodiment of the present invention.

[0027] Reference numerals in the drawings: aircraft 1, self-sustaining channel 2, gas storage tank 3, regenerative cooling channel 4, porous medium layer 5, cooling working medium supply channel 6, water storage tank 7, water supply pipeline 8, gas supply pipeline 9, spray cooler 10, first check valve 11, waterway solenoid valve 12, first flow valve 13, second check valve 14, gas path solenoid valve 15, pressure regulating valve 16, second flow valve 17, temperature sensor 18, third flow valve 19.

[0028] The realization of the object of the present invention, its functional features and advantages will be further described in conjunction with the embodiments and with reference to the drawings. Detailed implementation manners

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0030] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0031] In addition, in the present invention, descriptions such as "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0032] In the present invention, unless otherwise clearly defined and limited, terms such as "connection" and "fixation" shall be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or an integral one; it may be a mechanical connection, an electrical connection, a physical connection or a wireless communication connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0034] This embodiment discloses a gas-phase transpiration cooling thermal protection system based on self-sustaining channel supply (hereinafter referred to as "gas-phase transpiration cooling thermal protection system"), which mainly includes a gas source supply device and a gas-phase transpiration cooling thermal protection device.

[0035] Reference Figure 1 , the gas source supply device is mainly used to suck the external high-speed oncoming flow into the aircraft 1 as the gas source of the gas-phase transpiration cooling thermal protection system. The gas source supply device in this embodiment includes a self-sustaining channel 2, a gas storage tank 3, a regenerative cooling channel 4 and a spray cooling assembly provided inside the aircraft 1. The self-sustaining channel 2 includes a front section and a rear section, and the length ratio of the front section to the rear section is 1:1 to 2. The first end of the front section is open and located at the head of the aircraft 1, the first end of the rear section is connected to the second end of the front section, and the second end of the rear section is connected to the gas storage tank 3 for sucking the high-speed oncoming flow and transporting it to the gas storage tank 3. The regenerative cooling channel 4 is provided around the front section, and low-temperature fuel flows therein for regenerative cooling, that is, heat exchange is carried out between the low-temperature fuel and the high-speed oncoming flow to achieve the first cooling of the high-speed oncoming flow. The spray cooling assembly includes a plurality of spray coolers 10 provided in the rear section, and sprays are carried out on the high-speed oncoming flow in the rear section through the spray coolers 10 to achieve the second cooling of the high-speed oncoming flow, so that the temperature of the high-speed oncoming flow finally entering the gas storage tank 3 is reduced to a preset range.

[0036] Reference Figure 1, the gas-phase transpiration cooling thermal protection device includes a porous medium layer 5 and a coolant supply channel 6. The porous medium layer 5 is provided on the outer surface of the aircraft 1. One end of the coolant supply channel 6 is connected to the gas storage tank 3, and the other end extends to the inner surface of the porous medium layer 5, and there is an opening on the coolant supply channel 6 that communicates with the inner surface of the porous medium layer 5. The porous medium layer 5 can be designed as a flat plate or an arc to adapt to the shape of the surface of the aircraft 1. Among them, the flat porous medium layer 5 is applicable to the flat area of the aircraft 1, and the arc-shaped porous medium layer 5 is applicable to the curved surface area of the aircraft 1, such as the wing, the leading edge of the fuselage, etc. In the specific application process, the number of the porous medium layers 5 can be flexibly configured according to the thermal protection requirements of the aircraft 1 and distributed in each required area of the aircraft 1. The extended end of the coolant supply channel 6 has extended branches corresponding to each porous medium layer 5 for supplying coolant to the corresponding porous medium layer 5. Reference Figure 2 , during the flight of the aircraft 1, the coolant transported by the coolant supply channel 6 flows out from the porous medium layer 5, thereby forming a relatively thick cooling layer on the surface of the aircraft 1, so as to play a role in heat insulation and protecting the porous medium layer 5, preventing the high-temperature oncoming flow from directly ablating the porous medium layer 5.

[0037] The gas source supply device in this embodiment utilizes the high-temperature and high-pressure oncoming flow after introducing the bow shock wave through the self-sustaining channel 2, and through a unique secondary cooling design and the natural pressurization mechanism of the gas storage tank 3, realizes the stable transportation of the gaseous coolant. Compared with the traditional transpiration cooling system that often relies on a large amount of coolant to meet the thermal protection requirements, the gas-phase transpiration cooling thermal protection system in this embodiment greatly reduces the mass of the coolant that the aircraft 1 needs to carry, while ensuring the cooling efficiency, improves the endurance of the aircraft 1.

[0038] The spray cooler 10 in this embodiment is a gas-liquid two-phase nozzle, which is made of high-temperature resistant and corrosion-resistant stainless steel or ceramic materials to withstand the impact of the high-speed oncoming flow and the high-temperature environment, ensuring the reliability and durability of the system. The spray cooling assembly also includes a water storage tank 7, a water supply pipeline 8 and a gas supply pipeline 9. One end of the water supply pipeline 8 is connected to the water storage tank 7, and the other end is respectively connected to each spray cooler 10; one end of the gas supply pipeline 9 is connected to the gas storage tank 3, and the other end is respectively connected to each spray cooler 10. That is, the natural pressurization of the gas storage tank 3 is used to provide a stable driving pressure for the coolants of spray cooling and transpiration cooling, so that the gas storage tank 3 not only serves as a storage and transportation unit for the cooling medium, but also provides power for the spray cooler 10 through its natural pressurization characteristics, realizing the integrated supply of the cooling medium and power. In addition, the need for pumping coolant is eliminated, which not only greatly reduces the overall load of the aircraft 1, improves the flight performance, but also enhances the overall reliability of the system and the simplicity of maintenance.

[0039] In the specific implementation process, the water supply pipeline 8 includes a main water supply path and several water supply branch paths, and each water supply branch path corresponds to a spray cooler 10 one by one. The first end of the main water supply path is connected to the water storage tank 7, the first end of each water supply branch path is connected to the second end of the main water supply path, the second end of each water supply branch path is respectively connected to the liquid phase inlet of the corresponding spray cooler 10, a first check valve 11 and a water path solenoid valve 12 are arranged on the main water supply path, and a first flow valve 13 is arranged on each water supply branch path. The bottom of the water storage tank 7 is provided with a water outlet, and the main water supply path is connected to the water outlet, so that the spray water in the water storage tank 7 can flow into the main water supply path under the action of its own gravity, and a water level sensor is installed in the water storage tank 7 to be able to monitor the water level in the tank in real time. Among them, the first check valve 11 is used to prevent water from flowing back into the water storage tank 7 and ensure the unidirectionality of the water flow. The water path solenoid valve 12 is used to control the on-off of the water supply pipeline 8, and the first flow valve 13 is used to control the water flow rate flowing to each spray cooler 10.

[0040] In the specific implementation process, the gas supply pipeline 9 includes a main gas supply path and several gas supply branch paths, and each gas supply branch path corresponds to a spray cooler 10 one by one. The first end of the main gas supply path is connected to the gas storage tank 3, the first end of each gas supply branch path is connected to the second end of the main gas supply path, the second end of each gas supply branch path is respectively connected to the gas phase inlet of the corresponding spray cooler 10, a second check valve 14, a gas path solenoid valve 15 and a pressure regulating valve 16 are arranged on the main gas supply path, and a second flow valve 17 is arranged on each gas supply branch path. Among them, the second check valve 14 is used to prevent gas from flowing back into the gas storage tank 3 and ensure the unidirectionality of the gas flow. The gas path solenoid valve 15 is used to control the on-off of the gas supply pipeline 9, the pressure regulating valve 16 is used to adjust the pressure of the gas output from the gas storage tank 3 to ensure the stable driving pressure of the spray cooler 10, and the second flow valve 17 is used to control the gas flow rate flowing to each spray cooler 10.

[0041] As a preferred implementation manner, the nozzle aperture of the spray cooler 10 is 0.5 - 2 mm, the spray angle is 90° - 120°, and the spray coolers 10 appear in pairs in the latter part and are spaced apart along the gas flow direction. Among them, the two paired spray coolers 10 are symmetrically arranged on the channel wall of the latter part, and any one of the spray coolers 10 is located in the spray field of the other spray cooler 10, so as to effectively avoid the gas temperature around the spray cooler 10 from being too high, thereby increasing the service life of the spray cooler 10 and reducing the maintenance cost.

[0042] Further preferably, the distance between adjacent pairs of spray coolers 10 gradually increases along the gas flow direction. Since the high-speed air flow will gradually decelerate due to resistance during the flow process, in this embodiment, increasing the downstream distance can compensate for the extended residence time caused by the reduced flow rate, ensuring that the contact time between the air flow and the droplets in each cooling stage tends to be consistent, and avoiding insufficient front-end contact or excessive back-end accumulation.

[0043] Further preferably, temperature sensors 18 are provided on the channel walls of the rear section and at positions corresponding to the downstream of each pair of spray coolers 10. The detection surface of the temperature sensor 18 is flush with the channel wall of the rear section to ensure that the flow field boundary layer is not disturbed. The leads of the temperature sensors 18 are led out through preset lead grooves, and the lead grooves are filled with high-temperature-resistant insulating materials to ensure the stable transmission of sensor signals. By setting the temperature sensors 18 at the positions downstream of each pair of spray coolers 10, the cooling effect of each pair of spray coolers 10 is monitored, so as to guide the opening and closing of other spray coolers 10 or the adjustment of the spray volume. For example, if the temperature sensor 18 downstream of the first pair of spray coolers 10 detects that the temperature of the air flow has been reduced to the preset range, other spray coolers 10 downstream can be controlled to stop spraying. For another example, if the temperature sensor 18 downstream of the last pair of spray coolers 10 detects that the temperature of the air flow has not been reduced to the preset range, some or all of the spray coolers 10 can be controlled to increase the spray volume. In this embodiment, the temperature sensors 18 are high-precision and high-reliability thermocouple temperature sensors 18, such as platinum-rhodium-platinum thermocouples.

[0044] In the specific implementation process, the regenerative cooling channel 4 is a spiral flow channel wound around the outer wall of the front section to increase the heat exchange area and heat exchange time between the fuel and the oncoming flow.

[0045] In the specific implementation process, the structure of the gas storage tank 3 is designed as a spherical or cylindrical shape to withstand the pressure of the internal high-pressure gas, and the inner wall surface of the gas storage tank 3 is subjected to anti-corrosion treatment to prevent the corrosion of the inner wall of the tank by the moisture in the gas. At the same time, the gas storage tank 3 is equipped with a pressure gauge for real-time monitoring of its internal pressure to ensure that the system operates within a safe pressure range.

[0046] In the specific implementation process, third flow valves 19 are provided on each extension branch of the cooling working medium supply channel 6 to control the flow rate of the cooling working medium supplied by the gas storage tank 3 for transpiration cooling and ensure the cooling demand.

[0047] In this embodiment, the porous medium layer has two implementation modes:

[0048] In the first implementation mode, the porous medium layers in each area of the aircraft are all made of high-temperature alloy or composite ceramic materials with a certain porosity, so that they can work stably for a long time in a high-temperature and high-heat flux environment. At this time, the porosity of the porous medium layer is 10% - 70% and the thickness is 2 - 20 mm, which can be determined according to the heat load and cooling requirements.

[0049] In the second implementation mode, the porous medium layer in the leading edge area of the aircraft adopts an intermittent transpiration layout and a gradient porosity design, and the porous medium layers in other areas adopt the first implementation mode described above.

[0050] The intermittent sweating layout means that the porous medium layer includes a number of porous medium units and a number of solid walls. Each porous medium unit is arranged at intervals along the flow direction of the aircraft surface, and there is a solid wall between every two adjacent porous medium units. Among them, the porous medium unit is made of a high-temperature alloy or composite ceramic material with a certain porosity, and the solid wall is made of a non-porous high-temperature alloy.

[0051] By spatially discontinuously arranging the porous medium, the discontinuous discharge of the coolant on the leading edge surface is realized, which not only effectively reduces the entrainment effect of the mainstream on the coolant, enhances the coverage ability of the coolant on the hot end wall surface, but also optimizes the distribution of the coolant, making the coolant more effectively utilized in the high heat flux region and significantly improving the overall cooling efficiency.

[0052] The gradient porosity design means that according to the spatial distribution characteristics of the heat flux density, the flow rate and distribution of the coolant are adjusted by designing gradient porosity materials. Specifically, the porous medium unit in the leading edge stagnation region is defined as the first porous medium, the porous medium unit in the leading edge region close to the stagnation point is defined as the second porous medium, and the porous medium unit in other leading edge regions is defined as the third porous medium. Among them, the porosity of the second porous medium is greater than that of the first porous medium and the third porous medium, and the porosity of each second porous medium gradually increases along the arc radius direction, and the porosity of each third porous medium decreases in turn along the flow direction. In the specific implementation process, three regions can be divided according to the peak region of the heat flux density. For example: the entire leading edge is divided into a high heat region, a medium heat region and a low heat region. Among them, starting from the very front end (stagnation point) of the aircraft leading edge, the region corresponding to the position where the flow extends along the flow direction to the position where the heat flux density reaches 90% of the maximum heat flux density in the stagnation region is the high heat region, and the porous medium unit in the high heat region is the first porous medium; starting from the end of the high heat region, the region corresponding to the position where the flow extends along the flow direction to the position where the heat flux density drops to 50% of the maximum heat flux density in the stagnation region is the medium heat region, and the porous medium unit in the medium heat region is the second porous medium; starting from the end of the medium heat region, the region corresponding to the position where the flow extends along the flow direction to the end of the leading edge is the low heat region, and the porous medium unit in the low heat region is the third porous medium.

[0053] The working mechanism of single-phase transpiration cooling consists of two aspects. On the one hand, it is the convective heat transfer between the coolant and the solid skeleton in the porous medium. On the other hand, it is the heat blocking effect formed on the surface of the medium after flowing out of the porous medium. The position of the bow shock is closer to the nose cone stagnation point, and at this time, the pressure difference between the inside and outside of the porous medium is the smallest, so the heat blocking effect is almost lost. In this case, transpiration cooling relies more on convective heat transfer. The increase in porosity will lead to a decrease in the specific surface area inside the porous medium, insufficient heat transfer between the coolant and the solid skeleton, a decrease in the effective thermal conductivity of the porous medium, a reduction in the heat that the coolant can carry away, and a weakening of the cooling effect. Therefore, a porous medium with a smaller porosity should be selected at the stagnation point. For the leading edge area close to the stagnation point, the porosity distribution should show a rapid increasing trend along the arc radius direction because the permeability increases with the increase in porosity, and the coolant can more easily enter the porous medium with a larger porosity, rapidly increasing the thickness of the gas film layer in this area, protecting the wall surface by the coolant film, and reducing the heat that the mainstream can transfer to the wall surface. Finally, a gradually decreasing porosity arrangement is adopted for the middle and rear parts of the leading edge because the pressure difference between the inside and outside of the porous medium gradually increases along the flow direction, and the flow resistance of the coolant in the porous medium gradually decreases. Therefore, by gradually reducing the porosity, the trend of increasing coolant flow is offset, enabling more coolant to flow to the leading edge stagnation point area, improving the temperature uniformity on the surface of the porous medium, reducing the temperature gradient, and enhancing the overall thermal protection effect on the leading edge wall surface. This method can basically increase the temperature drop of the leading edge peak by about 5% and the temperature drop of the average temperature by 10% - 15% on the basis of intermittent transpiration cooling.

[0054] The above are only the preferred embodiments of the present invention, and do not limit the protection scope of the present invention. Any equivalent structural transformation made under the inventive concept of the present invention, or direct / indirect application in other related technical fields, is included in the protection scope of the present invention.

Claims

1. A gas phase sweating cooling thermal protection system based on self-sustaining channel supply, characterized in that: It includes a gas source supply device and a gas phase sweating cooling heat protection device; The gas source supply device includes a self-sustaining channel, a gas storage tank, a regenerative cooling channel and a spray cooling component arranged inside the aircraft, and the gas phase sweat cooling heat protection device includes a porous medium layer and a cooling medium supply channel; The self-sustaining channel comprises a front section and a rear section, wherein the first end of the front section is open and located at the head of the aircraft, the first end of the rear section is connected to the second end of the front section, and the second end of the rear section is connected to the gas tank for sucking high-speed incoming flow and delivering it to the gas tank; The regenerative cooling channel is arranged around the front section to utilize low-temperature fuel for regenerative cooling to achieve the first cooling of the high-speed incoming flow; the spray cooling assembly includes a plurality of spray coolers arranged in the rear section to perform the second cooling of the high-speed incoming flow; The porous medium layer is arranged on the outer surface of the aircraft, one end of the cooling medium supply channel is connected to the gas storage tank, and the other end extends to the inner surface of the porous medium layer, and the cooling medium supply channel has an opening connected to the inner surface of the porous medium layer; The spray cooling assembly also includes a water storage tank, a water supply pipeline and an air supply pipeline; One end of the water supply pipeline is connected to the water storage tank, and the other end is connected to each of the spray coolers; One end of the gas supply pipeline is connected to the gas storage tank, and the other end is respectively connected to each of the spray coolers.

2. The gas phase sweating cooling thermal protection system based on self-sustaining channel supply according to claim 1 is characterized in that: The water supply pipeline includes a main water supply line and a plurality of water supply branches, each of which corresponds to the spray cooler one by one; the first end of the main water supply line is connected to the water storage tank, the first end of each of the water supply branches is connected to the second end of the main water supply line, and the second end of each of the water supply branches is respectively connected to the corresponding spray cooler, the main water supply line is provided with a first check valve and a water circuit solenoid valve, and each of the water supply branches is provided with a first flow valve; The gas supply pipeline includes a main gas supply line and a plurality of gas supply branches, each of the gas supply branches corresponds to the spray cooler one by one; the first end of the main gas supply line is connected to the gas storage tank, the first end of each of the gas supply branches is connected to the second end of the main gas supply line, the second end of each of the gas supply branches is respectively connected to the corresponding spray cooler, the main gas supply line is provided with a second check valve, a gas circuit solenoid valve and a pressure regulating valve, and each of the gas supply branches is provided with a second flow valve.

3. The gas phase sweating cooling thermal protection system based on self-sustaining channel supply according to claim 1 or 2, characterized in that: The spray coolers appear in pairs in the rear section and are spaced apart along the flow direction of the gas; The two spray coolers in a pair are symmetrically arranged on the channel wall of the rear section, and any one of the spray coolers is located in the spray field of the other spray cooler.

4. The gas phase sweating cooling thermal protection system based on self-sustaining channel supply according to claim 3 is characterized in that: The distance between two adjacent pairs of the spray coolers gradually increases along the flow direction of the gas.

5. The gas phase sweating cooling thermal protection system based on self-sustaining channel supply according to claim 3 is characterized in that: A temperature sensor is provided on the channel wall of the rear section and at a position corresponding to the downstream of each pair of the spray coolers, and the detection surface of the temperature sensor is flush with the channel wall of the rear section.

6. The gas phase sweating cooling thermal protection system based on self-sustaining channel supply according to claim 1 or 2, characterized in that: The regeneration cooling channel is a spiral flow channel coiled on the outer wall of the front section.

7. The gas phase sweating cooling thermal protection system based on self-sustaining channel supply according to claim 1 or 2, characterized in that: The cooling medium supply channel is provided with a third flow valve.

8. The gas phase sweating cooling thermal protection system based on self-sustaining channel supply according to claim 1 or 2, characterized in that: The porous medium layer has a porosity of 10% to 70% and a thickness of 2 to 20 mm.

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