Thermal protection structure of dredging coupling semi-open type dissipation structure

Abstract

The invention relates to a heat protection structure of a dredging coupling semi-open type dissipation structure, which belongs to the technical field of heat protection of high-speed aircrafts and comprises a dredging structure shell, a dredging structure capillary core body, a dredging structure working medium, a semi-open type dissipation structure, a semi-open type dissipation working medium, a semi-open type dissipation structure exhaust pipe and a semi-open type dissipation structure control switch. Aiming at a local high-heating part of a hypersonic aircraft, on the basis of semi-active dredging type uniform-temperature heat protection, phase change heat absorption and discharge heat dissipation of an active dissipation working medium are combined, and heat absorption and dissipation ways are increased, so that the total heat amount is effectively reduced while the internal heat distribution of the structure is optimized, and the heat dissipation efficiency is improved. Internal heat control and management of the structure are realized through coupling of dredging semi-active heat protection and active dissipation, the problem of non-ablative heat protection in an extreme environment is solved, and a feasible heat protection technical approach is provided for performance improvement of high-speed aircrafts in the future.

Description

Technical Field

[0001] The invention belongs to the technical field of thermal protection of high-speed aircraft, and in particular relates to a thermal protection structure of a dredge-coupled semi-open dissipative structure. Background Art

[0002] In recent years, as the speed of high-speed aircraft continues to increase, the aerodynamic heating of local high heat flow areas such as the leading edge of the fuselage and the leading edge of the wings and rudders has continued to increase, and the operating temperature has become higher and higher, reaching or even exceeding the upper temperature limit of the existing thermal protection material system.

[0003] Conduit thermal protection is an important way to protect local high heat flux areas of high-speed aircraft. Unlike passive thermal protection, semi-active thermal protection is based on the idea of ​​active thermal management. It achieves rapid heat transfer or efficient heat dissipation through innovative structures, and can effectively solve the problem of non-ablative thermal protection in extreme environments. Conduit thermal protection developed in recent years is a typical innovative way to solve the problem of non-ablative thermal protection in local high heat flux areas. It is a semi-active thermal protection method that embodies the idea of ​​internal heat transfer and dissipation, and shows extremely high application potential.

[0004] The basic principle of the conduction type: Based on the idea of ​​active heat management, it abandons the method of simple heat blocking and on-site consumption, and realizes the rapid transmission and efficient dissipation of the incoming heat through the internal working fluid phase change and transportation, which can significantly improve the system's heat protection ability. Conduction-type thermal protection generally uses high-temperature heat pipes as a heat conduction path, and its main heat dissipation method is radiation heat dissipation, which has the problem of insufficient heat dissipation capacity. In order to improve its ability to cope with extreme environments, conduction-type thermal protection generally uses high-temperature heat pipes as a heat conduction path, and its main heat dissipation method is radiation heat dissipation, which has the problem of insufficient heat dissipation capacity. Summary of the invention

[0005] The technical problem solved by this application is: to overcome the shortcomings of the prior art and provide a thermal protection structure of a dredge-coupled semi-open dissipative structure. For local high-heating components of hypersonic aircraft, on the basis of semi-active dredge-type uniform temperature heat protection, the phase change heat absorption and discharge heat dissipation of active dissipative working fluid are combined to increase the heat absorption and dissipation pathways, thereby optimizing the internal heat distribution of the structure while effectively reducing the total amount of heat. Through the coupling of dredge-type semi-active heat protection and active dissipation, the internal heat control and management of the structure is achieved, solving the problem of non-ablative thermal protection in extreme environments, and providing a feasible thermal protection technology approach for improving the performance of future high-speed aircraft.

[0006] The technical solutions provided by this application are as follows:

[0007] A thermal protection structure of a drainage-coupled semi-open dissipative structure, comprising a drainage structure shell, a drainage structure capillary core, a drainage structure working medium, a semi-open dissipative structure, a dissipative working medium, an exhaust pipe and a control switch, wherein the interior of the drainage structure shell is a closed space, the drainage structure capillary core covers the entire inner wall of the drainage structure shell and is tightly connected thereto, the drainage structure capillary core has a porous capillary structure, and the drainage structure working medium is within the porous capillary structure of the drainage structure capillary core; the semi-open dissipative structure is connected to the inner wall of the drainage structure shell, the semi-open dissipative structure, the dissipative working medium is within the semi-open dissipative structure, one end of the exhaust pipe is located within the semi-open dissipative structure, and the other end extends out of the drainage structure shell, and the control switch is connected to the exhaust pipe for controlling the opening and closing of the exhaust pipe.

[0008] The housing of the drainage structure is made of high-temperature alloy.

[0009] The porous capillary structure of the capillary core of the drainage structure is formed by screen weaving, sintering or 3D printing.

[0010] The working medium of the drainage structure is alkali metal.

[0011] The dissipative working medium is an alkali metal.

[0012] The semi-open dissipation structure includes a dissipation shell and a dissipation capillary core. One side of the dissipation shell is fixedly connected to the inner wall of the drainage structure shell. The dissipation capillary core covers the inner wall of the dissipation shell. The dissipation capillary core is a porous capillary structure. One end of the exhaust pipe is located in the dissipation shell and passes through the fixed side to the outside of the drainage structure shell.

[0013] The semi-open dissipative structure also includes a liquid storage structure. The side where the dissipative shell is fixedly connected to the inner wall of the drainage structure shell is the fixed side. The dissipative capillary core covers the inner wall of the dissipative shell that does not contain the fixed side and is tightly connected to the dissipative shell. The liquid storage structure is connected to the inner wall of the dissipative shell on the fixed side. The liquid storage structure is a porous capillary structure. The liquid storage structure is connected to the dissipative capillary core, and the thickness of the liquid storage structure is greater than the dissipative capillary core.

[0014] The semi-open dissipative structure also includes a filling pipe, one end of which extends into the dissipative shell and the other end passes through the outside of the drainage structure shell, and is used to fill the dissipative working medium into the dissipative shell.

[0015] A reinforcing rib is fixedly connected inside the dissipation shell.

[0016] In summary, this application at least includes the following beneficial technical effects:

[0017] 1. High heat protection capability. The thermal protection structure with dredge-coupled semi-open dissipation structure can meet the leading edge thermal protection requirements in extreme environments.

[0018] 2. Good designability. The conducting medium and dissipating medium can be changed according to the actual thermal environment of the leading edge, and the design range is wide. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of a thermal protection structure of a dredge-coupled semi-open dissipative structure;

[0020] Figure 2 Embodiment calculation model;

[0021] Figure 3 Temperature field distribution results of passive solid metal state;

[0022] Figure 4 Temperature field distribution results of pure dredging heat protection structure state;

[0023] Figure 5 Temperature field distribution results of semi-open dissipative structure with equivalent power of 1.0kW;

[0024] Figure 6 Temperature field distribution results of semi-open dissipative structure with equivalent power of 2.0kW;

[0025] Figure 7 Temperature field distribution results of semi-open dissipative structure with equivalent power of 6.0kW;

[0026] Figure 8 The schematic diagram of the active-passive coupled heat conduction protection structure;

[0027] Fig. 9 This is the structural diagram of the semi-open dissipative structure. DETAILED DESCRIPTION

[0028] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments disclosed in the present invention will be further described in detail below with reference to the accompanying drawings.

[0029] like Figure 1 As shown, the embodiment of the present application provides a thermal protection structure of a drainage-coupled semi-open dissipative structure proposed by the present invention, including a drainage structure shell 1, a drainage structure capillary core 2, a drainage structure medium 3, a semi-open dissipative structure 4, a dissipative medium 5, an exhaust pipe 6, and a control switch 7. Among them, the drainage structure shell 1 is a part of the leading edge structure of the aircraft, and one end of the drainage structure shell 1 is a tip. The interior of the drainage structure shell 1 is a closed space, the drainage structure capillary core 2 is closely connected to the drainage structure shell 1, the drainage structure medium 3 is inside the drainage structure capillary core 2, the semi-open dissipative structure 4 is connected to the inner wall of the drainage structure shell 1, the dissipative medium 5 is inside the semi-open dissipative structure 4, the semi-open dissipative structure 4 is connected to the exhaust pipe 6, and the exhaust pipe 6 extends out of the drainage structure shell 1 and is isolated from the external environment by the control switch 7.

[0030] The housing 1 of the drainage structure is made of high-temperature alloy, and its shape includes but is not limited to wedge-shaped, conical or special-shaped, and the minimum leading edge radius can be up to millimeter level.

[0031] The drainage structure shell 1 is formed into a hollow enclosed space by welding or 3D printing, preferably 3D printing.

[0032] The capillary core 2 of the drainage structure is formed into a porous capillary structure by screen weaving, sintering or 3D printing, preferably by 3D printing.

[0033] The working medium 3 of the drainage structure is an alkali metal.

[0034] The semi-open dissipative structure 4 includes a dissipative shell 41, a dissipative capillary core 42, a liquid storage structure 43 and a filling pipe 44. One side of the dissipative shell 41 is fixedly connected to the inner wall of the drainage structure shell 1, and the side of the dissipative shell 41 fixedly connected to the inner wall of the drainage structure shell 1 is the fixed side; the dissipative capillary core 42 covers the inner wall of the dissipative shell 41 without the fixed side and is closely connected to the dissipative shell 41; one end of the exhaust pipe 6 is located in the dissipative shell 41 and passes through the fixed side to the outside of the drainage structure shell 1. The dissipative shell 41 is also provided with a liquid storage structure 43 on the inner wall of the fixed side. The liquid storage structure 43 is a porous capillary structure. The liquid storage structure 43 is connected to the dissipative capillary core 42, and the thickness of the liquid storage structure 43 is greater than that of the dissipative capillary core 42. One end of the filling pipe 44 extends into the dissipative shell 41 and the other end passes through the outside of the drainage structure shell 1, which is used to fill the dissipative working medium 5 into the dissipative shell 41. The dissipative capillary core 42 allows the liquid dissipative medium 5 to have a larger contact area with the drainage structure shell 1, thereby improving the heat exchange efficiency, and the liquid dissipative medium 5 in the liquid storage structure 43 can be replenished into the dissipative capillary core 42 in time through capillary action. A reinforcing rib 45 is fixedly connected inside the dissipative shell 41.

[0035] The shape of the semi-open dissipative structure 4 is determined according to actual use requirements, including but not limited to spherical, rectangular or special shapes.

[0036] The dissipative working medium 5 is an alkali metal.

[0037] The control switch 7 is an adaptive control switch, which can be opened adaptively according to pressure and temperature.

[0038] In order to improve its ability to cope with extreme environments, this patent has developed Figure 8 The active-passive coupled heat dissipation system shown in the figure. Among them, the self-starting active heat dissipation draws on the design of the capillary core transport system to realize the working fluid storage, gas-liquid separation and transport functions, overcoming the shortcomings of the working fluid drive supply system required by traditional active thermal protection, such as system complexity and large use compensation. The overall structure is as follows Fig. 9 As shown in the figure.

[0039] Example

[0040] In order to illustrate the feasibility of this method, we designed a thermal protection structure of a canalization-coupled semi-open dissipative structure and calculated its active cooling performance. The relevant parameters are set as follows: The thermal protection structure of the canalization-coupled semi-open dissipative structure includes a canalization structure shell, a canalization structure capillary core, a canalization structure working fluid, a semi-open dissipative structure, a semi-open dissipative working fluid, a semi-open dissipative structure exhaust pipe, and a semi-open dissipative structure control switch. Among them, the canalization structure is a closed space, the canalization structure capillary core is closely connected to the canalization structure shell, the canalization structure working fluid is inside the canalization structure capillary core, the semi-open dissipative working fluid is inside the semi-open dissipative structure, the semi-open dissipative structure exhaust pipe is connected to the semi-open dissipative structure, and is isolated from the external environment through the semi-open dissipative structure control switch.

[0041] In this embodiment, the housing of the drainage structure is made of niobium-based high-temperature alloy, lithium is selected as the drainage working fluid, the calculation state is Ma8, H=30km, the equivalent power of the semi-open dissipative structure is 1.0, 2.0, and 6.0kW respectively, and the passive solid metal state without any heat protection structure and the state with only the drainage heat protection structure (corresponding to the equivalent power of the semi-open dissipative structure is 0) are calculated at the same time. The calculation model is as follows: Figure 2 The working principle is as follows: in the working state, the stagnation point and large area of ​​the drainage structure are heated, and the heat is transferred from the stagnation point area to the inside of the heat pipe cavity, the drainage working medium evaporates and gradually starts to work, the local high-heated stagnation point is the evaporation point, the local low-heated point and the semi-open dissipation structure are the condensation point, and the steam in the cavity transfers the heat of the local high heat flow part to the local low heat flow part and the surface of the semi-open dissipation structure through convection and phase change heat transfer, so that the entire heat protection structure is isothermal, and the heat is effectively dissipated through the semi-open dissipation structure, reducing the thermal protection pressure of the sharp leading edge stagnation point area and improving the thermal protection performance.

[0042] Figure 3 This is the temperature field calculation result of a passive solid metal state without any heat protection structure. Figure 4 The temperature field calculation results are as follows: Figure 5-Figure 7The temperature field calculation results of the semi-open dissipative structure with equivalent powers of 1.0, 2.0, and 6.0kW are shown. Passive solid metals only rely on the heat transfer characteristics of metals to dissipate heat, and the stagnation temperature is about 1920K. Too high a stagnation temperature will damage the appearance of the thermal protection structure. After adding the drainage heat protection, the stagnation temperature is significantly reduced to 1350K, which is 570K lower than the passive heat protection scheme. After coupling the semi-open dissipative structure heat protection, the corresponding equivalent powers are 1.0, 2.0, and 6.0kW, respectively. The stagnation temperatures are 992K, 809K, and 797K, respectively, which are 358K, 541K, and 553K lower than the pure drainage scheme, and 928K, 1111K, and 1123K lower than the pure passive heat protection scheme. It can be seen that the cooling capacity provided by the semi-open dissipation mechanism is very considerable. On the basis of the cooling effect, the semi-open dissipation mechanism can continue to significantly reduce the leading edge stagnation temperature and improve thermal safety. However, the calculation results also show that the stagnation temperature cannot continue to decrease with the increase of the heat absorption power of the semi-open dissipation structure. When the heat absorption power exceeds 2.0kW, the stagnation temperature will tend to stabilize. At this time, the temperature of a large area behind the stagnation point is low, and the temperature of the tail cover plate has dropped to below 100K. The temperature difference of the entire structure mainly comes from the thermal resistance introduced by the wall thickness at the stagnation point. In fact, the heat absorption power provided by the semi-open dissipation structure cannot always maintain a constant value. When the structure drops to a lower temperature, the heat absorption power will also decrease until it reaches equilibrium. Therefore, in actual design, a reasonable design of the semi-open dissipation structure is very critical to the overall thermal protection structure.

[0043] The contents not described in detail in this application specification belong to the common knowledge of those skilled in the art.

[0044] The present application is described in detail above in conjunction with specific implementation methods and exemplary examples, but these descriptions cannot be understood as limiting the present application. Those skilled in the art understand that, without departing from the spirit and scope of the present application, a variety of equivalent replacements, modifications or improvements can be made to the technical solution of the present application and its implementation methods, all of which fall within the scope of the present application. The scope of protection of the present application shall be subject to the attached claims.

Claims

1. A thermal protection structure of a dredge-coupled semi-open dissipative structure, characterized in that: The invention comprises a drainage structure shell (1), a drainage structure capillary core (2), a drainage structure working medium (3), a semi-open dissipative structure (4), a dissipative working medium (5), an exhaust pipe (6) and a control switch (7); the interior of the drainage structure shell (1) is a closed space; the drainage structure capillary core (2) covers the entire inner wall of the drainage structure shell (1) and is closely connected thereto; the drainage structure capillary core (2) has a porous capillary structure; the drainage structure working medium (3) is in the porous capillary structure of the drainage structure capillary core (2); the semi-open dissipative structure (4) is connected to the inner wall of the drainage structure shell (1); the semi-open dissipative structure (4) and the dissipative working medium (5) are in the semi-open dissipative structure (4); one end of the exhaust pipe (6) is located in the semi-open dissipative structure (4) and the other end extends out of the drainage structure shell (1); the control switch (7) is connected to the exhaust pipe (6) and is used to control the opening and closing of the exhaust pipe (6).

2. The thermal protection structure of the conductive coupled semi-open dissipation structure according to claim 1, characterized in that: The drainage structure shell (1) is made of high-temperature alloy.

3. The thermal protection structure of the conductive coupled semi-open dissipation structure according to claim 1, characterized in that: The porous capillary structure of the drainage structure capillary core (2) is formed by screen weaving, sintering or 3D printing.

4. The thermal protection structure of the conductive coupled semi-open dissipation structure according to claim 1, characterized in that: The working medium (3) of the drainage structure is an alkali metal.

5. The thermal protection structure of the conductive coupled semi-open dissipation structure according to claim 1, characterized in that: The dissipative working medium (5) is an alkali metal.

6. The thermal protection structure of the conductive coupled semi-open dissipation structure according to claim 1, characterized in that: The semi-open dissipation structure (4) comprises a dissipation shell (41) and a dissipation capillary core (42); one side of the dissipation shell (41) is fixedly connected to the inner wall of the drainage structure shell (1); the dissipation capillary core (42) covers the inner wall of the dissipation shell (41); the dissipation capillary core (42) is a porous capillary structure; one end of the exhaust pipe (6) is located in the dissipation shell (41) and passes through the fixed side to the outside of the drainage structure shell (1).

7. The thermal protection structure of the conductive coupled semi-open dissipation structure according to claim 6, characterized in that: The semi-open dissipative structure (4) further comprises a liquid storage structure (43); the side of the dissipative shell (41) fixedly connected to the inner wall of the drainage structure shell (1) is the fixed side; the dissipative capillary core (42) covers the inner wall of the dissipative shell (41) not including the fixed side and is tightly connected to the dissipative shell (41); the liquid storage structure (43) is connected to the inner wall of the dissipative shell (41) on the fixed side; the liquid storage structure (43) is a porous capillary structure; the liquid storage structure (43) is connected to the dissipative capillary core (42); and the thickness of the liquid storage structure (43) is greater than that of the dissipative capillary core (42).

8. The thermal protection structure of the conductive coupled semi-open dissipation structure according to claim 6, characterized in that: The semi-open dissipation structure (4) further comprises a filling pipe (44), one end of which extends into the dissipation shell (41) and the other end of which passes through the outside of the drainage structure shell (1), and is used to fill the dissipation working medium (5) into the dissipation shell (41).

9. The thermal protection structure of the conductive coupled semi-open dissipation structure according to claim 6, characterized in that: A reinforcing rib (45) is fixedly connected inside the dissipation shell (41).

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