Flexible thermal protection structure for a fuselage of a high-speed morphing aircraft and method of operation

Abstract

This invention relates to a flexible thermal protection structure and operating method for the fuselage of high-speed morphing aircraft, belonging to the field of aircraft structure technology. The invention uses fish-scale-shaped heat-insulating tiles as the flexible thermal protection structure to protect the aircraft's interior from high temperatures during high-speed flight; a C-shaped frame and woven heat-insulating felt serve as the thermal sealing structure between the fish-scale-shaped heat-insulating tiles, ensuring no heat leakage occurs between the tiles during operation; an outer sleeve and an inner sleeve form a thin-walled sleeve structure to support the flexible skin, enabling it to withstand large loads in multiple stable states; and SMA wires and springs serve as the driving mechanism to actively control the flexible skin to different deformation shapes. This invention has a compact structure, strong thermal protection capabilities, and flexible deformation capabilities, making it of significant application value in the field of aircraft thermal protection design.

Description

Technical Field

[0001] This invention relates to a flexible thermal protection structure and operation method for the fuselage of a high-speed morphing aircraft. The fuselage is designed based on a fish-scale distributed high-load-bearing thermal protection structure and a multi-stable thin-walled sleeve support structure. It is applicable to the design of flexible thermal protection structures for modern aircraft and belongs to the field of aircraft structure technology. Background Technology

[0002] Faced with the development requirements of rapid penetration military aircraft and low-cost intelligent spacecraft, the development of high-speed morphing aircraft has become an important research direction. Flexible thermal protection structures, which adapt to changes in the shape of morphing aircraft through compliant deformation, are a key technology for ensuring structural load-bearing capacity and deformation coordination under high-speed morphing conditions. Smooth, continuous, and compliant fuselage deformation can effectively increase fuel capacity and volumetric efficiency, more precisely meeting fuel and aerodynamic requirements. At low speeds, the bulging fuselage configuration provides good lift characteristics and can carry a large amount of fuel; at high speeds, the fuselage contracts to a flat shape, reducing aerodynamic drag, increasing skin thickness, and enhancing thermal protection. This research is innovative. Currently, high-speed aircraft thermal protection structures have a certain degree of flexibility and can be bent, but they cannot guarantee consistent surface contact under any stable condition. There is currently no relevant research in China on the engineering application of deformable structure thermal protection. Summary of the Invention

[0003] The purpose of this invention is to design a mechanism capable of protecting against the high temperatures generated by air friction at hypersonic speeds while simultaneously allowing for flexible deformation. Addressing the shortcomings of existing rigid heat-resistant tile structures that cannot simultaneously achieve both thermal protection and flexible deformation, this invention proposes a flexible thermal protection scheme for the fuselage that combines a fish-scale distributed high-load-bearing thermal protection structure with a multi-stable thin-walled sleeve support structure. This scheme is compact, possesses strong thermal protection capabilities, and can flexibly deform, making it of significant application value in the field of aircraft thermal protection design.

[0004] The technical solution of the present invention is a flexible thermal protection structure suitable for the fuselage of a high-speed variable-speed aircraft, comprising heat-insulating tiles 101, flexible skin 102, heat-sealing structure 103, and multistable driving cells; multiple heat-insulating tiles 101 are overlapped on the upper surface of the flexible skin 102 in the form of fish scales, and a heat-sealing structure 103 is installed at the overlap of every two adjacent heat-insulating tiles 101, and multiple multistable driving cells are fixedly installed on the lower surface of the flexible skin 102 in an array.

[0005] The multi-stable driving cell includes an outer sleeve 112, an inner sleeve 113, an SMA wire 110, a spring 109, and a heating sleeve 111. The heating sleeve 111, spring 109, inner sleeve 113, and outer sleeve 112 are sequentially sleeved on the SMA wire 110, and the two ends of the spring 109 are connected to the two ends of the SMA wire 110.

[0006] The outer sleeve 112 and the inner sleeve 113 form a thin-walled sleeve structure. The inner surface of the outer sleeve 112 is evenly distributed with multiple grooves that are adapted to the protrusions on the outer surface of the inner sleeve 113.

[0007] The multistable driving cells are arranged in an array to form a multistable driving structure.

[0008] The heat-sealing structure 103 includes a C-shaped frame 104 and a woven heat insulation felt 105; the woven heat insulation felt 105 is fixedly installed on the concave surfaces of two parallel C-shaped frames 104, and the upper and lower surfaces of the C-shaped frames 104 are respectively connected to the adjacent heat insulation tiles 101.

[0009] The height of the heat-sealing structure 103 is 1cm-20cm.

[0010] The C-shaped frame 104 is elastic. When the gap between the heat insulation tiles 101 is small, the C-shaped frame 104 is compressed; when the gap between the heat insulation tiles 101 is large, the C-shaped frame 104 opens.

[0011] The angle of the C-shaped frame 104 in its open state is consistent with the angle formed by the heat insulation tile 101 and the flexible skin 102.

[0012] The described operation method for the flexible thermal protection structure applicable to the fuselage of a high-speed variator aircraft involves the fuselage 108 deforming under the action of a multi-stable driving structure. The flexible skin deforms, the heat insulation tiles warp, the gaps between the heat insulation tiles increase, and the C-shaped skeleton 104 of the heat-sealing structure 103 at the overlap of adjacent heat insulation tiles opens. When the fuselage 108 returns to its shape under the action of the multi-stable driving structure, the flexible skin deformation recovers, the gaps between the heat insulation tiles decrease, and the C-shaped skeleton 104 of the heat-sealing structure 103 at the overlap of adjacent heat insulation tiles closes. The outer sleeve 112 and the inner sleeve 113 constitute a thin-walled sleeve structure. Under axial load, the thin-walled sleeve structure deforms, achieving multiple stable radial deformation states. The SMA wire 110 is heated and contracts, driving the thin-walled sleeve structure to maintain multiple stable states. When the SMA wire 110 cools, a spring drives the thin-walled sleeve structure to return to its initial state.

[0013] The beneficial effects of this invention are as follows: This invention provides a flexible thermal protection structure suitable for the fuselage of a high-speed morphing aircraft. It uses fish-scale-shaped heat-insulating tiles as the flexible thermal protection structure to protect the aircraft's interior from high temperatures during high-speed flight. A C-shaped frame and woven heat-insulating felt serve as the thermal sealing structure between the fish-scale-shaped heat-insulating tiles, ensuring that heat leakage does not occur between the tiles during operation. An outer sleeve and an inner sleeve form a thin-walled sleeve structure to support the flexible skin, enabling it to withstand large loads in multiple stable states. SMA wires and springs serve as the driving mechanism to actively control the flexible skin to different deformation shapes. Attached Figure Description

[0014] Figure 1 Schematic diagram of fish-scale patterned heat insulation tile distribution;

[0015] Figure 2 Schematic diagram of a fish-scale thermal protection scheme;

[0016] Figure 3 Schematic diagram of the heat sealing structure between insulation tiles;

[0017] Figure 4 Schematic diagram of a multistable structure driving scheme.

[0018] Among them: 101-heat insulation tile, 102-flexible skin, 103-heat sealing structure, 107-wing, 108-fuselage, 109-spring, 110-SMA wire, 111-heating sleeve, 112-outer sleeve, 113-inner sleeve. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] like Figure 2 As shown, a flexible thermal protection structure suitable for the fuselage of a high-speed variable-speed aircraft includes heat-insulating tiles 101, a flexible skin 102, a heat-sealing structure 103, and multistable actuation cells. Multiple heat-insulating tiles 101 are overlapped on the upper surface of the flexible skin 102 in a fish-scale pattern and fixed to the flexible skin 102 with pins to form a cantilever beam structure. A heat-sealing structure 103 is installed at the overlap of every two adjacent heat-insulating tiles 101, sealing the gaps between the heat-insulating tiles 101 during movement. Multiple multistable actuation cells are fixedly installed in an array on the lower surface of the flexible skin 102.

[0021] The multistable structure driving scheme of the present invention is as follows: Figure 4 As shown, the wing 107 is connected to the fuselage 108. The fuselage 108 can change shape under the action of a actuator. The multistable actuation cell includes an outer sleeve 112, an inner sleeve 113, an SMA wire 110, a spring 109, and a heating sleeve 111. The heating sleeve 111, spring 109, inner sleeve 113, and outer sleeve 112 are sequentially fitted onto the SMA wire 110, with both ends of the spring 109 connected to both ends of the SMA wire 110. The outer sleeve 112 and inner sleeve 113 form a thin-walled sleeve structure. Multiple grooves are evenly distributed on the inner surface of the outer sleeve 112 to fit the protrusions on the outer surface of the inner sleeve 113. The multistable actuation cells are arranged in an array to form a multistable actuation structure, enabling it to withstand large loads in multiple stable states. The SMA wire 110 and spring 109 act as a driving mechanism, actively controlling the flexible skin to different deformation shapes. The heating sleeve 111 heats the SMA wire 110 for actuation.

[0022] like Figure 3As shown, the heat-sealing structure 103 includes a C-shaped frame 104 and a woven heat insulation felt 105. The woven heat insulation felt 105 is fixedly installed on the concave surfaces of two parallel C-shaped frames 104. The upper and lower surfaces of the C-shaped frames 104 are respectively connected to adjacent heat insulation tiles 101. The C-shaped frames 104 are elastic. When the gap between the heat insulation tiles 101 is small, the C-shaped frames 104 are compressed; when the gap between the heat insulation tiles 101 is large, the C-shaped frames 104 open. The angle of the C-shaped frames 104 in the open state is consistent with the angle formed by the heat insulation tiles 101 and the flexible skin 102. The height of the heat-sealing structure 103 is 1cm-20cm.

[0023] The described operation method for the flexible thermal protection structure applicable to the fuselage of a high-speed variator aircraft involves the fuselage 108 deforming under the action of a multi-stable driving structure. The flexible skin deforms, the heat insulation tiles warp, the gaps between the heat insulation tiles increase, and the C-shaped skeleton 104 of the heat-sealing structure 103 at the overlap of adjacent heat insulation tiles opens. When the fuselage 108 returns to its shape under the action of the multi-stable driving structure, the flexible skin deformation recovers, the gaps between the heat insulation tiles decrease, and the C-shaped skeleton 104 of the heat-sealing structure 103 at the overlap of adjacent heat insulation tiles closes. The outer sleeve 112 and the inner sleeve 113 constitute a thin-walled sleeve structure. Under axial load, the thin-walled sleeve structure deforms, achieving multiple stable radial deformation states. The SMA wire 110 is heated and contracts, driving the thin-walled sleeve structure to maintain multiple stable states. When the SMA wire 110 cools, a spring drives the thin-walled sleeve structure to return to its initial state.

[0024] Fish scale type heat insulation tiles Figure 1 As shown, it is composed of multiple heat insulation tiles 101 arranged in an array. The heat insulation tiles 101 are all fixed to the flexible skin 102 by pins. During the movement, gaps will be formed between the heat insulation tiles 101, thereby ensuring flexible movement.

[0025] The above description is merely a preferred embodiment of the present invention, and the present invention should not be limited to the content disclosed in this embodiment and the accompanying drawings. Any equivalent or modified embodiments made without departing from the spirit of the present invention fall within the scope of protection of the present invention.

Claims

1. A flexible thermal protection structure suitable for the fuselage of a high-speed variator aircraft, characterized in that, The system includes heat insulation tiles (101), a flexible skin (102), a heat-sealing structure (103), and multistable drive cells. Multiple heat insulation tiles (101) overlap the upper surface of the flexible skin (102) in a fish-scale pattern. A heat-sealing structure (103) is installed at the overlap of every two adjacent heat insulation tiles (101). Multiple multistable drive cells are fixedly installed on the lower surface of the flexible skin (102) in an array. The multistable drive cells include an outer sleeve (112), an inner sleeve (113), an SMA wire (110), a spring (109), and a heating sleeve (111). The heating sleeve (111), spring (109), and inner sleeve... (113) The outer sleeve (112) is sequentially sleeved on the SMA wire (110), and the two ends of the spring (109) are connected to the two ends of the SMA wire (110); the outer sleeve (112) and the inner sleeve (113) form a thin-walled sleeve structure, and the inner surface of the outer sleeve (112) is evenly distributed with multiple grooves that are adapted to the protrusions on the outer surface of the inner sleeve (113); the heat-sealing structure (103) includes a C-shaped frame (104) and a woven heat insulation felt (105); the woven heat insulation felt (105) is fixedly installed on the concave surface of two parallel C-shaped frames (104), and the upper and lower surfaces of the C-shaped frames (104) are respectively connected to the adjacent heat insulation tiles (101).

2. The flexible thermal protection structure for the fuselage of a high-speed variator aircraft according to claim 1, characterized in that, The multistable driving cells are arranged in an array to form a multistable driving structure.

3. The flexible thermal protection structure for the fuselage of a high-speed variator aircraft according to claim 1, characterized in that, The height of the heat-sealing structure (103) is 1 cm-20 cm.

4. The flexible thermal protection structure suitable for the fuselage of a high-speed variator aircraft according to claim 1, characterized in that, The C-shaped frame (104) is elastic. When the gap between the heat insulation tiles (101) is small, the C-shaped frame (104) is compressed; when the gap between the heat insulation tiles (101) is large, the C-shaped frame (104) opens.

5. The flexible thermal protection structure suitable for the fuselage of a high-speed variator aircraft according to claim 1, characterized in that, The angle of the C-shaped frame (104) in its open state is consistent with the angle formed by the heat insulation tile (101) and the flexible skin (102).

6. The method of operating the flexible thermal protection structure for the fuselage of a high-speed variator aircraft according to any one of claims 1-5, characterized in that, The fuselage (108) deforms under the action of the multi-stable driving structure, the flexible skin deforms, the heat insulation tiles lift up, the gap between the heat insulation tiles increases, and the C-shaped skeleton (104) of the heat-sealing structure (103) at the overlap of adjacent heat insulation tiles opens; when the fuselage (108) recovers its shape under the action of the multi-stable driving structure, the flexible skin deforms and recovers, the gap between the heat insulation tiles decreases, and the C-shaped skeleton (104) of the heat-sealing structure (103) at the overlap of adjacent heat insulation tiles closes; the outer sleeve (112) and the inner sleeve (113) constitute a thin-walled sleeve structure, which deforms under axial load to achieve multiple stable radial deformation states, the SMA wire (110) is heated and shrinks, driving the thin-walled sleeve structure to maintain multiple stable states; the SMA wire (110) is cooled, and the spring drives the thin-walled sleeve structure to return to its initial state.

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