Active cooling temperature control type high-temperature-resistant intelligent skin for cross-domain aircraft

Abstract

The invention discloses an active cooling temperature control type high-temperature-resistant intelligent skin for a cross-domain aircraft, and belongs to the field of aerospace. The device comprises a silicone rubber skin structure and a shape memory polymer matrix, the silicone rubber skin structure is attached to the surface of the shape memory polymer matrix, active cooling pipes are distributed in the silicone rubber skin structure in a winding mode, and flowing pipelines are axially distributed in the shape memory polymer matrix. And the active cooling pipe and the flowing pipeline are flexible pipelines made of flexible polymers and are respectively connected with the coolant storage tank and the high-temperature fluid heat storage tank. A smooth continuous deformation wing structure capable of meeting the high bearing requirement and the low-speed large deformation requirement of a cross-domain aircraft in high-speed and high-temperature environments at the same time is designed, and the problems that an existing material is limited and a shape memory intelligent skin is difficult to heat are solved; temperature regulation and control of the structure in different flight states are achieved, heating driving can be conducted without filling a resistance wire or bonding a heating film, and higher engineering application potential is achieved.

Description

TECHNICAL FIELD

[0001] The application relates to an active cooling temperature control type high-temperature-resistant intelligent skin for a cross-domain aircraft, and belongs to the field of aerospace. BACKGROUND

[0002] A cross-domain aircraft is an advanced flight platform capable of freely switching flight modes between different airspaces (such as near space, inside and outside the atmosphere) and various speed ranges (subsonic, supersonic and hypersonic). Through the integration of innovative aerodynamic design, propulsion systems and thermal management technology, the cross-domain aircraft realizes seamless transition from low-speed cruising to high-speed penetration. The importance of the cross-domain aircraft lies in breaking the task boundary of traditional aircraft, combining the flexibility of aircraft and the strategic coverage capability of spacecraft, and can perform high-value tasks such as reconnaissance, rapid global strike and space access. In the military field, the cross-domain aircraft can break through the existing air defense system and form an asymmetric advantage. In the civil field, the cross-domain aircraft lays the foundation for hypersonic transportation and reusable space-air return technology, and is a key embodiment of the national aerospace strategic competitiveness.

[0003] The cross-domain aircraft has a large flight airspace and a wide speed range, and the flight environment is complex. The wide speed range flight working condition determines that the aerodynamic layout of the aircraft must simultaneously consider high and low speed performance. The aircraft must have a high lift-drag ratio at high Mach numbers and be able to generate a large lift at low speed flight conditions, so that the aircraft has the ability to take off and land horizontally. The aerodynamic design experience of subsonic, transonic and supersonic wings shows that for the same configuration, the flow mechanism of lift enhancement and drag reduction is different at different speed ranges. The shape of the upper surface of the wing has a great influence on the lift at low speed, while the shape of the lower surface of the wing has a great influence on the lift at high speed. Therefore, the cross-domain aircraft has contradictory requirements for the wing configuration in the high and low speed range. If the wing configuration remains unchanged, it is undoubtedly a very severe problem to realize the all-airspace and wide-speed-range large maneuvering flight of the aircraft. In contrast, the morphing wing aircraft that can change the wing configuration according to the task requirements and flight environment provides a new solution to solve the above-mentioned contradiction.

[0004] Silicone rubber and shape memory polymer are both representative materials commonly used in the design of morphing wing structures. Silicone rubber is an ideal choice for the morphing skin structure of a morphing aircraft due to its excellent flexibility and elastic deformation capability. Its high elongation (up to more than 500%) can adapt to large-scale deformation of the wing without cracking. Shape memory polymer has two major characteristics: variable stiffness and shape memory. When the temperature of the material is below the glass transition temperature, the material is in a glassy state and has high stiffness. When the temperature of the material is above the glass transition temperature, the material is in a rubbery state and has low stiffness. By changing the temperature, the material can freely switch between the two states. This characteristic enables the intelligent skin structure based on shape memory polymer to overcome the contradiction between high out-of-plane load bearing and large in-plane deformation caused by wing surface morphing design, and achieve smooth and continuous deformation. However, silicone rubber has poor load bearing performance and requires additional load bearing and driving structures, which often leads to design compromises due to weight and space constraints, resulting in suboptimal wing deformation for the aircraft. Shape memory materials face challenges such as heating and driving difficulties and limited high-temperature resistance, making it difficult to adapt to the aerodynamic heating environment of the aircraft flying at high speed in the atmosphere.

[0005] Therefore, there is an urgent need for an active cooling temperature-controlled high-temperature-resistant intelligent skin for cross-domain aircraft to solve the above technical problems. SUMMARY

[0006] The purpose of the present application is to design a smooth and continuous deformation wing structure that can simultaneously meet the high load bearing requirements of cross-domain aircraft at high speed and high temperature environments and the low speed large deformation requirements. To overcome the limitations of existing materials such as silicone rubber and shape memory polymer, which have poor load bearing and poor temperature resistance, a brief overview of the present application is given below to provide a basic understanding of certain aspects of the present application. It should be understood that this summary is not an exhaustive summary of the present application. It is not intended to determine the key or important parts of the present application, nor is it intended to limit the scope of the present application.

[0007] Technical scheme of the present application:

[0008] An active cooling temperature-controlled high-temperature-resistant intelligent skin for cross-domain aircraft, comprising a silicone rubber skin structure and a shape memory polymer matrix, the silicone rubber skin structure is attached to the surface of the shape memory polymer matrix, the silicone rubber skin structure has a serpentine distribution of active cooling pipes, the shape memory polymer matrix has an axial distribution of flow pipes, the active cooling pipes and the flow pipes are flexible pipes made of flexible polymer, and each is connected to a coolant tank and a high-temperature fluid heat storage tank.

[0009] Preferably, the shape memory polymer matrix is formed by curing shape memory epoxy resin in a mold, and has a carbon fiber skeleton inside.

[0010] Preferably, the silicone rubber skin structure is prepared by a molding process, and has an internal aluminum oxide filler.

[0011] Preferably, the silicone rubber skin structure and the shape memory polymer matrix are connected by a polyimide-based adhesive.

[0012] Preferably, the flexible pipe is a fluororubber pipe.

[0013] Preferably, the fluororubber pipe has an internal boron nitride filler.

[0014] Preferably, the flow pipe is arranged in an axial direction and has a gradient in thickness, i.e., the flow pipe is denser on the side closer to the silicone rubber skin structure than on the side farther from the silicone rubber skin structure.

[0015] Preferably, the coolant tank contains coolant, which is injected into the flexible pipe during active cooling, and the fluid is injected from the flexible pipe into the coolant tank after the structure is heated during deformation of the high-temperature fluid heating structure at low speed.

[0016] Preferably, the high-temperature fluid storage tank is a high-temperature fluid storage device with heat preservation function, and the completed coolant is injected from the flexible pipe into the high-temperature fluid storage tank during active cooling, and the fluid is injected from the high-temperature fluid storage tank during deformation of the high-temperature fluid heating structure at low speed.

[0017] Preferably, the temperature adjustment method is different during deformation at high speed and during deformation at low speed, and during deformation at low speed, the coolant tank does not work, and the shape memory polymer matrix is heated by injecting high-temperature fluid from the high-temperature fluid storage tank; during deformation at high speed, the coolant tank starts to work, and the coolant is injected into the silicone rubber skin structure and the shape memory polymer matrix from the coolant tank through the active cooling pipe and the flow pipe, respectively, to maintain the internal temperature of the shape memory polymer matrix, and during deformation, the flow rate of the coolant is reduced, and high-temperature fluid does not need to be injected.

[0018] The present application has the following advantages:

[0019] 1. The present application improves the adaptability of the thermally induced shape memory intelligent skin structure in high-temperature environments, and overcomes the shortcomings that it is difficult to adapt to changes in a wide range of flight conditions.

[0020] 2. The present application drives by adjusting the flow rate of the coolant in the active cooling pipe, which has higher reliability and engineering realizability compared with the traditional method of filling resistance wires or bonding heating films and electrifying to heat.

[0021] 3. This invention integrates deformation and load-bearing functions, eliminating the need for additional design of separate load-bearing and driving structures, thereby minimizing design compromises caused by weight and space limitations;

[0022] 4. This invention can realize the recovery and utilization of aerodynamic thermal energy, effectively improving the energy utilization rate throughout the flight process;

[0023] 5. This invention enables rapid, smooth, and continuous deformation across a wide speed range, providing a key skin foundation for the variable configuration design of various cross-domain aircraft, and has extremely high engineering application value. Attached Figure Description

[0024] Figure 1 This is a 3D view of an active cooling temperature-controlled high-temperature resistant smart skin for cross-domain aircraft;

[0025] Figure 2 This is a schematic diagram showing the combination of the silicone rubber skin structure and the active cooling pipe;

[0026] Figure 3 This is a schematic diagram of the fit between the shape memory polymer matrix and the flow channel;

[0027] Figure 4 This is a flowchart illustrating the deformation method under high-speed flight conditions as described in Specific Implementation Method Two;

[0028] Figure 5 This is a flowchart illustrating the deformation method under high-speed flight conditions as described in Specific Implementation Method 3.

[0029] In the diagram: 1-Silicone rubber skin structure, 2-Shape memory polymer matrix, 3-Active cooling pipe, 4-Flow pipe, 5-Coolant storage tank, 6-High temperature fluid heat storage tank. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0031] Specific implementation method one: Combining Figures 1-3To illustrate the embodiment, the active cooling temperature-controlled high-temperature-resistant intelligent skin for cross-domain aircraft of the embodiment comprises a silicone rubber skin structure 1 and a shape memory polymer matrix 2, the silicone rubber skin structure 1 is attached to the surface of the shape memory polymer matrix 2, the silicone rubber skin structure 1 has active cooling pipes 3 distributed in a meandering manner, and the shape memory polymer matrix 2 has flow channels 4 distributed in an axial direction, the active cooling pipes 3 and the flow channels 4 are flexible channels made of flexible polymers, and are respectively connected to a coolant storage tank 5 and a high-temperature fluid heat storage tank 6.

[0032] The shape memory polymer matrix 2 is formed by curing shape memory epoxy resin in a mold, and has a carbon fiber skeleton inside to improve the mechanical properties.

[0033] The silicone rubber skin structure 1 is made of methylphenyl silicone rubber by a molding process, and has aluminum oxide fillers inside to improve the thermal stability of the silicone rubber material.

[0034] The silicone rubber skin structure 1 and the shape memory polymer matrix 2 are connected by a polyimide-based adhesive, which has high-temperature resistance and flexibility.

[0035] The flexible channel is a fluororubber channel, and boron nitride fillers are added inside the fluororubber channel to improve the heat conduction capacity.

[0036] The active cooling pipes 3 are distributed in a meandering manner in the silicone rubber skin structure 1 to increase the contact area between the pipes and the silicone rubber skin structure 1, thereby improving the active cooling efficiency.

[0037] The flow channels 4 are arranged in an axial direction and have a gradient characteristic in thickness, that is, the flow channels 4 close to the silicone rubber skin structure 1 are denser than the flow channels 4 far from the silicone rubber skin structure 1, which is related to the gradient distribution of the internal temperature of the structure. When the structure is applied, the internal temperature distribution of the aircraft should be considered first to guide the arrangement design of the flow channels in the skin, and the ultimate goal is to realize the uniform distribution of the internal temperature of the structure.

[0038] The coolant storage tank 5 contains a coolant such as liquid water, and the coolant is injected into the flexible channel during active cooling. When the structure is deformed by heating the high-temperature fluid at low speed, the fluid is injected into the coolant storage tank 5 after the structure is heated.

[0039] The high-temperature fluid heat storage tank 6 is a high-temperature fluid storage device with heat preservation function, and the high-temperature fluid is, for example, heated liquid water. During active cooling, the completed coolant is injected into the high-temperature fluid heat storage tank 6, and the fluid flows out of the high-temperature fluid heat storage tank 6 when the structure is deformed by heating the high-temperature fluid at low speed.

[0040] The silicon rubber skin structure 1 can realize deformation / carrying integration through internal shape memory polymer. When carrying is needed, the shape memory temperature is adjusted to be below the glass transition temperature, the silicon rubber skin structure 1 keeps a high stiffness state to meet the carrying requirement; when deformation is needed, the shape memory temperature is adjusted to the glass transition temperature to realize temperature deformation of the silicon rubber skin structure 1.

[0041] The silicon rubber skin structure 1 is different from the driving mode of the thermal type shape memory skin structure in that the structure does not need to fill resistance wires or bond heating films to realize deformation driving through power heating of the skin structure, but realizes deformation driving of the structure by adjusting the flow rate of the coolant in the active cooling pipe 5 to regulate the internal temperature of the structure.

[0042] The temperature adjustment method is different when deforming in the high-speed flight state and when deforming in the low-speed flight state. In the low-speed flight state, the coolant tank 5 does not work, and when the aircraft structure needs to carry, i.e. deforms, the high-temperature fluid storage tank 6 injects high-temperature fluid to heat the shape memory polymer matrix 2; in the high-speed flight state, the coolant tank 5 starts to work, and in order to maintain the internal temperature of the shape memory polymer matrix 2, the coolant is injected into the silicon rubber skin structure 1 and the shape memory polymer matrix 2 through the active cooling pipe 3 and the flow pipe 4 from the coolant tank 5, and when deforming, the flow rate of the coolant is reduced, and there is no need to inject high-temperature fluid.

[0043] The silicon rubber skin structure 1 can realize recovery and utilization of aerodynamic thermal energy. The fluid in the fluid pipe 4 connected with the coolant tank 5 and the high-temperature fluid storage tank 6 can be stored as high-temperature fluid for use in subsequent low-speed flight.

[0044] There are two ways for the silicon rubber skin structure 1 to recover and utilize aerodynamic thermal energy:

[0045] When the aircraft needs to be heated in the high-speed flight state, the cooling effect of the shape memory polymer matrix 2 is reduced, and the aerodynamic heat brought by high-speed flight is directly used to heat the silicon rubber skin structure 1;

[0046] When the aircraft is flying in the high-speed flight state, the coolant is injected into the silicon rubber skin structure 1 from the coolant tank 5 and heated into high-temperature fluid, which is then recovered into the high-temperature fluid storage tank 6. These high-temperature fluids are used to heat the silicon rubber skin structure 1 in the low-speed flight state, realizing recovery and reuse of aerodynamic thermal energy.

[0047] Specific implementation method two: combination Figure 4 This embodiment is based on the specific implementation method one. The deformation method of the active cooling temperature control type high-temperature resistant intelligent skin for the cross-domain aircraft in the high-speed flight state is as follows:

[0048] When the aircraft is cruising at high speed, the coolant tank 5 connected to the silicone rubber skin structure 1 starts to work, and the coolant is injected into the shape memory polymer matrix 2 through the flow channel 4 at the same time;

[0049] When the aircraft structure needs to bear, the flow rate of the coolant in the active cooling pipe 3 is increased, so that the internal temperature of the shape memory polymer matrix 2 is below the glass transition temperature, at this time the silicone rubber skin structure 1 can maintain a high stiffness state to maintain the aerodynamic shape of the aircraft;

[0050] When the aircraft needs to adjust the wing surface configuration to obtain a new aerodynamic layout, the flow rate of the coolant in the active cooling pipe 3 is slowed down, and the internal temperature of the silicone rubber skin structure 1 is increased. When the shape memory polymer matrix 2 reaches the glass transition temperature, the shape memory polymer matrix 2 triggers the shape memory effect, and realizes the smooth and continuous deformation of the aircraft wing surface;

[0051] After the aircraft obtains a new wing surface configuration, the flow rate of the coolant in the active cooling pipe is adjusted, so that the internal temperature of the shape memory polymer matrix 2 is below the glass transition temperature again, and a high stiffness is maintained to maintain the aerodynamic shape of the aircraft.

[0052] Specific implementation three: combination Figure 5 Based on the specific implementation one, the deformation method of the active cooling temperature control type high temperature resistant intelligent skin for the cross-domain aircraft in the specific implementation one is as follows:

[0053] When the aircraft is flying at low speed, the coolant tank 5 connected to the silicone rubber skin structure 1 starts to stop working, and there is no coolant injection in the flow channel, and the shape memory polymer matrix 2 is in a normal temperature state. At this time, the silicone rubber skin structure 1 can maintain a high stiffness state to maintain the aerodynamic shape of the aircraft;

[0054] When the aircraft needs to adjust the wing surface configuration to obtain a new aerodynamic layout, high temperature fluid is injected from the high temperature fluid storage tank 6 through the flow channel 4 to heat the shape memory polymer matrix 2, so that the shape memory polymer matrix 2 reaches the glass transition temperature and triggers the shape memory effect, realizing the smooth and continuous deformation of the aircraft wing surface;

[0055] After the aircraft obtains a new wing surface configuration, the injection of high temperature fluid is stopped, and the completed fluid is recovered from the shape memory polymer matrix 2 to the coolant tank 5, so that the internal temperature is below the glass transition temperature again, and a high stiffness is maintained to maintain the aerodynamic shape of the aircraft.

[0056] Specific implementation four: combination Figures 1-5The embodiment is described based on the specific embodiment one. The active cooling temperature control type high-temperature-resistant intelligent skin for the cross-domain aircraft in the embodiment is used for a trans-atmosphere aircraft. Due to a wide air domain and a wide speed domain, the high- and low-speed domains have inconsistent requirements for the airfoil shape:

[0057] When taking off, the aircraft is in a full fuel state, has the heaviest weight, and has a prominent lift-weight contradiction. Therefore, the airfoil needs to have a high lift to meet the requirement of the maximum weight during takeoff.

[0058] When flying at a hypersonic speed, the weight of the aircraft is reduced with the consumption of fuel, and the lift-weight contradiction is gradually eased. However, at this time, the engine thrust and the drag are close to each other, and the thrust-drag contradiction is prominent. Therefore, the airfoil needs to reduce the drag as much as possible and improve the lift-drag ratio to meet the requirement of the thrust-drag matching design.

[0059] The high-temperature-resistant intelligent skin structure of the application can overcome the contradiction. When taking off, the airfoil adopts a high-lift airfoil to meet the requirement of the maximum weight during takeoff.

[0060] When flying at a hypersonic speed, the flow rate of the coolant is adjusted, the stiffness of the skin is reduced, and the airfoil of the aircraft is changed into a high-lift-drag-ratio airfoil under the action of the mechanism.

[0061] The embodiment improves the high-temperature-resistant performance of the shape memory intelligent skin and can be applied to the variable-configuration design of various hypersonic aircrafts.

[0062] If the airfoil of a hypersonic missile is designed by using the embodiment, the flight drag of the missile can be reduced, and a farther striking range can be obtained.

[0063] If the airfoil of a hypersonic reconnaissance aircraft is designed by using the embodiment, the cruising time and the cruising range of the aircraft can be greatly improved.

[0064] It should be noted that, in the above embodiments, any non-contradictory technical solution can be arranged and combined. Those skilled in the art can exhaust all possibilities according to the mathematical knowledge of arrangement and combination. Therefore, the application does not need to describe all the technical solutions after the arrangement and combination. However, it should be understood that the technical solutions after the arrangement and combination have been disclosed in the application.

[0065] The above description is only the preferred embodiments of the application and is not used to limit the application. Those skilled in the art can make various changes and modifications to the application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application should be included in the protection scope of the application.

Claims

1. A high-temperature resistant smart skin with active cooling and temperature control for cross-domain aircraft, characterized in that: It includes a silicone rubber skin structure (1) and a shape memory polymer matrix (2). The silicone rubber skin structure (1) is attached to the surface of the shape memory polymer matrix (2). Active cooling pipes (3) are distributed meanderingly inside the silicone rubber skin structure (1). Flow pipes (4) are distributed axially inside the shape memory polymer matrix (2). The active cooling pipes (3) and flow pipes (4) are flexible pipes made of flexible polymer, and they are respectively connected to a coolant storage tank (5) and a high-temperature fluid heat storage tank (6).

2. The active cooling temperature-controlled high-temperature resistant smart skin for cross-domain aircraft according to claim 1, characterized in that: The shape memory polymer matrix (2) is formed by curing shape memory epoxy resin in a mold, and has a carbon fiber skeleton inside.

3. The active cooling temperature-controlled high-temperature resistant smart skin for cross-domain aircraft according to claim 1, characterized in that: The silicone rubber skin structure (1) is made of methylphenyl silicone rubber by molding process, and has alumina filler inside.

4. The active cooling temperature-controlled high-temperature resistant smart skin for cross-domain aircraft according to claim 1, characterized in that: The silicone rubber skin structure (1) and the shape memory polymer matrix (2) are connected by a polyimide adhesive.

5. The active cooling temperature-controlled high-temperature resistant smart skin for cross-domain aircraft according to claim 1, characterized in that: The flexible pipe is a fluororubber pipe.

6. The active cooling temperature-controlled high-temperature resistant smart skin for cross-domain aircraft according to claim 5, characterized in that: Boron nitride filler is added inside the fluororubber pipe.

7. The active cooling temperature-controlled high-temperature resistant smart skin for cross-domain aircraft according to claim 1, characterized in that: The flow channels (4) are arranged axially with a gradient in thickness, that is, the flow channels (4) closer to the silicone rubber skin structure (1) are more densely packed than the flow channels (4) farther away from the silicone rubber skin structure (1).

8. The active cooling temperature-controlled high-temperature resistant smart skin for cross-domain aircraft according to claim 1, characterized in that: The coolant tank (5) contains coolant. During active cooling, the coolant is injected from the coolant tank (5) into the flexible pipe. During low-speed flight, when the structure is deformed by high-temperature fluid heating, the fluid is injected from the flexible pipe into the coolant tank (5) after the structure is heated.

9. The active cooling temperature-controlled high-temperature resistant smart skin for cross-domain aircraft according to claim 8, characterized in that: The high-temperature fluid heat storage tank (6) is a high-temperature fluid storage device with heat preservation function. During active cooling, the completed coolant is injected into the high-temperature fluid heat storage tank (6) through a flexible pipe. During low-speed flight, when the high-temperature fluid heating structure deforms, the fluid flows out from the high-temperature fluid heat storage tank (6).

10. The active cooling temperature-controlled high-temperature resistant smart skin for cross-domain aircraft according to claim 9, characterized in that: The temperature regulation methods differ between high-speed flight deformation and low-speed flight deformation. In low-speed flight, the coolant tank (5) does not work, and the shape memory polymer matrix (2) is heated by high-temperature fluid injected into the high-temperature fluid storage tank (6) during deformation. In high-speed flight, the coolant tank (5) starts to work. In order to maintain the internal temperature of the shape memory polymer matrix (2), the coolant is injected from the coolant tank (5) into the silicone rubber skin structure (1) and the shape memory polymer matrix (2) through the active cooling pipe (3) and the flow pipe (4). During deformation, the coolant flow rate is reduced, and there is no need to inject high-temperature fluid.

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