Liquid rocket engine lattice regenerative cooling structure thrust chamber and design method thereof

Abstract

The invention discloses a liquid rocket engine thrust chamber with a lattice regenerative cooling structure and a design method thereof, and belongs to the field of engines, and the design method comprises the following steps: determining the overall structure of the liquid rocket engine thrust chamber according to the project general situation; determining the lattice regenerative cooling structure as a truss lattice structure, selecting the truss lattice structure, and determining a layout mode; designing the determined three-dimensional model of the thrust chamber by using computer aided design software; exporting the three-dimensional model as an STL (Standard Template Library) file, and representing the surface of the three-dimensional model by using triangular grids by the STL file, so as to facilitate subsequent 3D printing treatment; and performing selective laser melting and printing to form a thrust chamber product, and performing post-treatment after printing is completed. The lattice regeneration cooling structure is directly arranged between the inner wall and the outer wall of the thrust chamber, so that the weight is greatly reduced, the effective heat transfer coefficient of the cooling channel is increased, the strength of the inner wall and the cooling channel is improved, and the service life of the thrust chamber is prolonged.

Description

Technical Field

[0001] The invention relates to the field of engines, and in particular to a thrust chamber of a liquid rocket engine lattice regenerative cooling structure and a design method thereof. Background Art

[0002] The thrust chamber is one of the core components of a liquid rocket engine. The thrust chamber is divided into a combustion chamber and a nozzle. The fuel and oxidizer are injected into the combustion chamber to complete the combustion. The high temperature and high pressure generated by the intense combustion can easily exceed the tolerance limit of the existing thrust chamber gas wall material. The throat temperature of the nozzle is also very high. After the convergence section, the temperature and pressure continue to rise, and the heat flow reaches the maximum. For reusable liquid rocket engines, people tend to be more concerned about their service life and use the lifespan as an indicator to evaluate whether the engine can continue to work.

[0003] Most of the liquid rocket engines currently in service and under development use regenerative cooling to cool the thrust chamber, that is, the fuel component or oxidizer component passes through the cooling groove, absorbs part of the heat generated by the combustion, and finally is sprayed into the combustion chamber through the liquid collecting ring for combustion. There are three main structural forms of the thrust chamber cooling groove of the existing liquid rocket engine: rectangular groove with pressure pit, corrugated plate structure and tube bundle structure. The gas side of the inner wall of the thrust chamber is subjected to high temperature, and the coolant side of the inner wall of the thrust chamber is subjected to lower temperature. The temperature difference is large, and under the action of high pressure, the inner wall is easily damaged and destroyed, so the life of the thrust chamber is relatively low. Domestic and foreign research regards the failure of the inner wall as the failure of the thrust chamber, and this is also the case in the life assessment and calculation of liquid rocket engines.

[0004] At present, traditional slot-type regenerative cooling is the most common cooling method for liquid rocket engines. As the wall heat flux gradually increases, simple regenerative cooling technology can no longer meet the demand; and the slot-type regenerative cooling channel is slender and has the characteristics of single-sided heating, which can easily cause serious thermal stratification and local heat transfer deterioration in the fuel. The new generation of liquid rocket engines needs to be lightweight and reusable, and the slot-type regenerative structure can no longer meet the demand.

[0005] In the patent document with publication number CN113153576A and invention name "Radiation Cooling Thrust Chamber Body Structure for Liquid Rocket Engine", a lattice structure is directly added to the outer wall of the thrust chamber to increase the radiation heat exchange area of ​​the outer wall of the thrust chamber. The purpose is only to increase the radiation heat exchange area and enhance the heat exchange. The outer wall of the thrust chamber itself has a low temperature, and the high temperature is mainly in the inner wall material. Not only does it not significantly increase the heat transfer effect, but it also increases the weight of the thrust chamber. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a liquid rocket engine lattice regenerative cooling structure thrust chamber with simple structure and reliable operation, and provides a design method for the liquid rocket engine lattice regenerative cooling structure thrust chamber.

[0007] The technical solution of the present invention to solve the above technical problems is: a liquid rocket engine lattice regenerative cooling structure thrust chamber, including an outer shell, a liquid collecting cavity and a propellant tube, the outer shell is surrounded by an inner wall and an outer wall, the inner side of the inner wall is a cavity, the cavity is funnel-shaped, and the cavity is divided into a combustion chamber and a nozzle by the throat, the outer side of the inner wall is the outer wall, a cooling channel is provided between the inner wall and the outer wall, a lattice regenerative cooling structure is provided in the cooling channel, a liquid collecting cavity and a propellant tube are provided on the outer wall, and the propellant tube, the liquid collecting cavity, the cooling channel and the combustion chamber are connected in sequence.

[0008] The above-mentioned liquid rocket engine lattice regenerative cooling structure thrust chamber, the lattice regenerative cooling structure is set as a truss-type lattice structure, adopting one of the six cell structures of Kagome lattice, body-centered cubic lattice BCC, body-centered cubic lattice BCCZ with vertical struts, truncated cube lattice, Kelvin cell lattice, and face-centered cubic lattice FCC.

[0009] The thrust chamber of the above-mentioned liquid rocket engine lattice regenerative cooling structure has an inner wall thickness of 0.4mm-1mm and an outer wall thickness of 1mm-6mm.

[0010] A method for designing a thrust chamber of a liquid rocket engine lattice regenerative cooling structure comprises the following steps: Step S1: Determine the overall structure of the liquid rocket engine thrust chamber according to the engineering overview; Step S2: determining that the lattice regenerative cooling structure is a truss lattice structure, selecting the truss lattice structure and determining a layout mode; Step S3: using computer-aided design software to design a three-dimensional model of the thrust chamber; Step S4: exporting the 3D model as an STL file, in which the surface of the 3D model is represented by a triangular mesh, which is convenient for subsequent 3D printing processing; Step S5: Selective laser melting is used to print the thrust chamber product, and post-processing is performed after printing is completed.

[0011] The design method of the thrust chamber of the lattice regenerative cooling structure of the above-mentioned liquid rocket engine, the specific process of step S2 is: Step S21: Select the manufacturing material, determine the side length of the Kagome, BCC, BCCZ, Truncated cube, kelvin cell, and FCC cell structure, and determine the wall thickness of the inner wall and the outer wall; Step S22: arbitrarily select a cell structure from among Kagome, BCC, BCCZ, Truncated cube, kelvin Cell, and FCC; Step S23: repeatedly arranging the selected cell structure in a three-dimensional space according to a set layout, thereby obtaining a lattice regenerative cooling structure.

[0012] In the above-mentioned method for designing the thrust chamber of the lattice regenerative cooling structure of the liquid rocket engine, in the step S21, the selected manufacturing material is one of titanium alloy, nickel-based alloy, and copper alloy.

[0013] In the above-mentioned method for designing a thrust chamber of a lattice regenerative cooling structure of a liquid rocket engine, in step S22, the lattice cells of the six cell structures are as follows: The lattice cell of Kagome is the first equilateral triangle, which is periodic on the plane; six first equilateral triangles form a hexagon. The mathematical expression of Kagome is: the side length of the first equilateral triangle is b, and the coordinates of the three vertices are expressed as: (0,0), ( , ), (b,0), in three-dimensional space, the first equilateral triangle of the plane forms a three-dimensional Kagome structure through rotation and translation; The lattice cell of BCC is the first cube, and there is a first node at the center and eight corners of the first cube. The mathematical expression of BCC is: the side length of the first cube is a, the coordinates of the first node at the center of the first cube are (a / 2, a / 2, a / 2), and the coordinates of the first nodes at the eight corners of the first cube are (0, 0, 0), (a, 0, 0), (0, a, 0), (0, 0, a), (a, a, 0), (a, 0, a), (0, a, a) and (a, a, a) respectively. The lattice cell of BCCZ is based on the lattice cell of BCC. Z-shaped supports are added to the diagonal direction of the lattice cell of BCC, i.e., the first cube. The Z-shaped supports connect the specified vertices and central atoms in the lattice cell of BCC to form a mesh structure. The lattice cell of the truncated cube is the fourth cube. A small cube is cut off from each vertex of the fourth cube. The eight vertices of the fourth cube are cut off by small cubes to form a truncated cube. The lattice cell of Kelvin Cell is a regular octahedron, and the eight faces of the regular octahedron are all equilateral triangles. A regular octahedron is selected as the initial structure, and the regular octahedron is truncated, that is, the triangular vertices of the six vertices of the regular octahedron are cut off to form a plane. After the truncation operation, each vertex position of the regular octahedron becomes a square, and each face of the regular octahedron becomes a regular hexagon; thus, 6 square faces and 8 hexagonal faces are formed; finally, the side length ratio of the hexagonal face and the square face is adjusted to obtain a complete cell structure; The FCC lattice is a symmetrical crystal structure whose lattice cell is a second cube, called the basic cube. There is a second node at the center of each of the six faces and eight vertices of the basic cube. The side length of the basic cube is c, and the coordinates of the second nodes at the centers of the six faces of the basic cube are: (c / 2,0,0), (0,c / 2,0), (0,0,c / 2), (c,c / 2,0), (c,0,c / 2), (c,c,c); the coordinates of the second nodes at the eight vertices of the basic cube are: (0,0,0), (c,0,0), (0,c,0), (0,0,c), (c,c,0), (c,0,c), (0,c,c), (c,c,c).

[0014] In the above-mentioned design method of the thrust chamber of the lattice regenerative cooling structure of the liquid rocket engine, in the step S23, the layout methods include circumferential layout, axial layout, spiral layout, grid layout, and gradient layout, and each layout method is implemented separately.

[0015] In the design method of the thrust chamber of the lattice regenerative cooling structure of the above-mentioned liquid rocket engine, in the step S23, the node spacing of the lattice regenerative cooling structure is designed with a gradient, and gradually changes along the direction of the cooling channel, that is, the node spacing at the combustion chamber position in the cooling channel is consistent, and the node spacing gradually increases as it extends toward the nozzle with the throat as the boundary, so as to achieve the cooling effect and mechanical property optimization of different parts.

[0016] In the above-mentioned method for designing the thrust chamber of the lattice regenerative cooling structure of the liquid rocket engine, in step S5, the post-processing includes support structure removal, heat treatment, surface treatment, dimensional correction and performance testing.

[0017] The beneficial effects of the present invention are: 1. Improved cooling efficiency. The lattice regenerative cooling structure significantly improves cooling efficiency by increasing the surface area of ​​the cooling channel. The complex geometry and high surface area inside the truss-like lattice structure allow the coolant to absorb heat more effectively, thereby maintaining the stability of the thrust chamber under high-temperature working conditions.

[0018] 2. Reduced material weight. The truss-type lattice structure has a high strength-to-weight ratio. Compared with the traditional solid structure, the truss-type lattice structure can significantly reduce the weight of the thrust chamber while maintaining the structural strength, which is of great significance for the overall weight control of the rocket engine and the improvement of the carrying capacity.

[0019] 3. Enhanced structural strength and reliability. The truss-type lattice structure improves the overall structural strength and reliability of the thrust chamber through its uniform distribution and unique geometric shape; the truss-type lattice structure can better disperse and resist external loads and thermal stresses, reducing the risk of deformation and damage of the thrust chamber in high temperature and high pressure environments.

[0020] 4. Improved manufacturing flexibility. The design method uses selective laser melting (SLM) technology to achieve high-precision manufacturing of lattice structures. SLM technology can manufacture complex geometric structures inside the thrust chamber, thereby improving the flexibility of design and manufacturing and meeting the specific needs of different rocket engines.

[0021] 5. Improved thermal management performance. The lattice regenerative cooling structure can achieve more precise thermal management. By designing truss-like lattice structures of different geometric shapes and densities, customized cooling effects can be achieved in different areas of the thrust chamber to ensure that the temperature of each part is controlled within the optimal range.

[0022] 6. Reduced thermal stress concentration. The traditional channel cooling structure is prone to thermal stress concentration in the sharply changing geometric area, leading to structural fatigue and failure. The truss-type lattice structure can effectively reduce the thermal stress concentration phenomenon and increase the service life of the thrust chamber due to its continuous and uniform characteristics.

[0023] 7. Improved overall performance. The truss-type lattice structure not only has advantages in cooling effect and structural strength, but also can optimize the aerodynamic performance and combustion efficiency of the thrust chamber, thereby improving the overall performance of the rocket engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the thrust chamber of the lattice regenerative cooling structure of the liquid rocket engine of the present invention.

[0025] Figure 2 This is a three-dimensional schematic diagram of six cell structures: Kagome, BCC, BCCZ, Truncatedcube, Kelvin cell, and FCC from left to right.

[0026] Figure 3 This is a cross-sectional view of the thrust chamber of the lattice regenerative cooling structure of a liquid rocket engine when the lattice regenerative cooling structure of the present invention adopts BCC.

[0027] Figure 4 This is a side view of the lattice regenerative cooling structure of the present invention when using BCC.

[0028] Figure 5 It is a schematic diagram of the overall model when the lattice regenerative cooling structure of the present invention adopts BCC.

[0029] In the figure, 1 is the liquid collecting chamber, 2 is the propellant tube, 3 is the inner wall, 4 is the outer wall, 5 is the throat, 6 is the combustion chamber, 7 is the nozzle, 8 is the cooling channel, and 9 is the lattice regeneration cooling structure. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0031] like Figure 1 As shown, a thrust chamber of a lattice regenerative cooling structure of a liquid rocket engine comprises an outer shell, a liquid collecting cavity 1 and a propellant tube 2, wherein the outer shell is enclosed by an inner wall 3 and an outer wall 4, the inner side of the inner wall 3 is a cavity, the cavity is funnel-shaped, and the cavity is divided into a combustion chamber 6 and a nozzle 7 by a throat 5, the outer side of the inner wall 3 is an outer wall 4, a cooling channel 8 is provided between the inner wall 3 and the outer wall 4, a lattice regenerative cooling structure 9 is provided in the cooling channel 8, a liquid collecting cavity 1 and a propellant tube 2 are provided on the outer wall 4, and the propellant tube 2, the liquid collecting cavity 1, the cooling channel 8 and the combustion chamber 6 are sequentially connected.

[0032] The lattice regenerative cooling structure 9 is set as a truss-type lattice structure, and adopts one of the six cell structures of Kagome, body-centered cubic (BCC), body-centered cubic with vertical struts (BCCZ), truncated cube, kelvin cell, and face-centered cubic (FCC).

[0033] The thickness of the inner wall 3 is 0.4 mm-1 mm, and the thickness of the outer wall 4 is 1 mm-6 mm.

[0034] The hole diameters of the liquid collecting chamber 1 and the propellant tube 2 can be flexibly designed according to the actual engineering application requirements.

[0035] A method for designing a thrust chamber of a liquid rocket engine lattice regenerative cooling structure comprises the following steps: Step S1: Determine the overall structure of the liquid rocket engine thrust chamber according to the engineering overview.

[0036] Step S2: Determine that the lattice regenerative cooling structure is a truss-type lattice structure, select the truss-type lattice structure and determine the layout mode.

[0037] The specific process of step S2 is: Step S21: Select the manufacturing material, such as titanium alloy, nickel-based alloy, copper alloy, etc., which has high strength, high heat resistance and good thermal conductivity. Determine the side length of the Kagome, BCC, BCCZ, Truncated cube, kelvin Cell, FCC cell structure, and determine the wall thickness of the inner wall and outer wall. The wall thickness needs to be reduced as much as possible while ensuring the structural strength to improve the cooling effect.

[0038] Step S22: arbitrarily select a cell structure from among Kagome, BCC, BCCZ, Truncated cube, kelvin Cell, and FCC; like Figure 2 As shown, Figure 2 From left to right in the figure are Kagome, BCC, BCCZ, Truncated cube, kelvinCell, and FCC cell structures. The lattice cells of the six cell structures are as follows: The lattice cell of Kagome is the first equilateral triangle, which is periodic on the plane; six first equilateral triangles form a hexagon. The mathematical expression of Kagome is: the side length of the first equilateral triangle is b, and the coordinates of the three vertices are expressed as: (0,0), ( , ), (b,0), in three-dimensional space, the first equilateral triangle of the plane forms a three-dimensional Kagome structure through rotation and translation; The lattice cell of BCC is the first cube, and there is a first node at the center and eight corners of the first cube. The mathematical expression of BCC is: the side length of the first cube is a, the coordinates of the first node at the center of the first cube are (a / 2, a / 2, a / 2), and the coordinates of the first nodes at the eight corners of the first cube are (0, 0, 0), (a, 0, 0), (0, a, 0), (0, 0, a), (a, a, 0), (a, 0, a), (0, a, a) and (a, a, a) respectively. The lattice cell of BCCZ is based on the lattice cell of BCC. Z-shaped supports are added to the diagonal direction of the lattice cell of BCC, i.e., the first cube. The Z-shaped supports connect the specified vertices and central atoms in the lattice cell of BCC to form a mesh structure. The lattice cell of the truncated cube is the fourth cube. A small cube is cut off from each vertex of the fourth cube. The eight vertices of the fourth cube are cut off by small cubes to form a truncated cube. The lattice cell of Kelvin Cell is a regular octahedron, and the eight faces of the regular octahedron are all equilateral triangles. A regular octahedron is selected as the initial structure, and the regular octahedron is truncated, that is, the triangular vertices of the six vertices of the regular octahedron are cut off to form a plane. After the truncation operation, each vertex position of the regular octahedron becomes a square, and each face of the regular octahedron becomes a regular hexagon; thus, 6 square faces and 8 hexagonal faces are formed; finally, the side length ratio of the hexagonal face and the square face is adjusted to obtain a complete cell structure; The FCC lattice is a symmetrical crystal structure whose lattice cell is a second cube, called the basic cube. There is a second node at the center of each of the six faces and eight vertices of the basic cube. The side length of the basic cube is c, and the coordinates of the second nodes at the centers of the six faces of the basic cube are: (c / 2,0,0), (0,c / 2,0), (0,0,c / 2), (c,c / 2,0), (c,0,c / 2), (c,c,c); the coordinates of the second nodes at the eight vertices of the basic cube are: (0,0,0), (c,0,0), (0,c,0), (0,0,c), (c,c,0), (c,0,c), (0,c,c), (c,c,c).

[0039] Step S23: repeatedly arranging the selected cell structure in a three-dimensional space according to a set layout, thereby obtaining a lattice regenerative cooling structure.

[0040] The layout modes include circumferential layout, axial layout, spiral layout, grid layout, and gradient layout, and each layout mode is implemented separately.

[0041] The rod diameter, inclination angle, cell size and node spacing of the lattice regenerative cooling structure are designed with a gradient and gradually change along the cooling channel direction. That is, the node spacing in the cooling channel located in the combustion chamber is consistent, and the node spacing gradually increases as it extends from the throat to the nozzle direction, so as to achieve cooling effects and mechanical properties optimization in different parts.

[0042] Step S3: Using computer-aided design software to design the determined three-dimensional model of the thrust chamber.

[0043] Step S4: Export the 3D model as an STL file. The STL file represents the surface of the 3D model with a triangular mesh, which is convenient for subsequent 3D printing. Select suitable metal powder materials, such as nickel-based alloys, titanium alloys, copper alloys, etc. The metal powder needs to have good fluidity and appropriate particle size distribution to ensure the smooth progress of the printing process.

[0044] Step S5: Selective laser melting (SLM) is used to print the thrust chamber product, and post-processing is performed after printing is completed. Post-processing includes support structure removal, heat treatment, surface treatment, size correction and performance testing.

[0045] The present invention designs a thrust chamber with a lattice regenerative cooling structure using BCC and conducts numerical simulation calculation research. A three-dimensional finite element analysis (FEA) software (such as workbench or ABAQUS) is used to perform a thermal-mechanical coupling simulation. The simulation is divided into four working stages: pre-cooling, hot operation, post-cooling, and relaxation. Each stage considers the transient effects of temperature changes and fluid flow. The numerical simulation is set to multiple cycles according to the working conditions, and the temperature field and stress-strain field distribution of the thrust chamber structure under thermal and mechanical loads are analyzed. It is found that the inner wall of the thrust chamber with a lattice regenerative cooling structure does not have the "dog chamber" phenomenon in the traditional groove thrust chamber, and the service life of the inner wall material reaches 202 times.

[0046] The present invention replaces the traditional cooling channel structure (pressed rectangular groove, corrugated plate structure and tube bundle structure), and directly arranges a lattice regenerative cooling structure between the inner and outer walls of the thrust chamber. The lattice regenerative cooling structure is set as a truss-type lattice structure, which greatly reduces the weight and achieves lightweight and high strength. It can solve the defects of the slender channel-type regenerative cooling channel and the single-sided heating that easily cause serious thermal stratification and local heat transfer deterioration of the fuel, increase the effective heat transfer coefficient of the cooling channel, greatly improve the heat transfer effect, and have good stability; improve the strength of the inner wall and the cooling channel, and the inner wall of the thrust chamber is evenly stressed, thereby delaying the occurrence of the "dog room" effect on the inner wall, increasing the service life of the thrust chamber, and greatly increasing the service life of the liquid rocket engine.

Claims

1. A liquid rocket engine lattice regenerative cooling structure thrust chamber, comprising a shell, a liquid collecting chamber and a propellant tube, characterized in that: The outer shell is surrounded by an inner wall and an outer wall. The inner side of the inner wall is a cavity, which is funnel-shaped. The cavity is divided into a combustion chamber and a nozzle by the throat. The outer side of the inner wall is the outer wall. A cooling channel is provided between the inner wall and the outer wall. A lattice regenerative cooling structure is provided in the cooling channel. A liquid collecting chamber and a propellant tube are provided on the outer wall. The propellant tube, the liquid collecting chamber, the cooling channel and the combustion chamber are connected in sequence.

2. The liquid rocket engine lattice regenerative cooling structure thrust chamber according to claim 1, characterized in that: The lattice regenerative cooling structure is set as a truss-type lattice structure, using one of the six cell structures of Kagome lattice, BCC body-centered cubic lattice, BCCZ body-centered cubic lattice with vertical struts, Truncated cube lattice, kelvinCell, and FCC face-centered cubic lattice.

3. The liquid rocket engine lattice regenerative cooling structure thrust chamber according to claim 2, characterized in that: The inner wall thickness is 0.4mm-1mm, and the outer wall thickness is 1mm-6mm.

4. A method for designing a thrust chamber of a liquid rocket engine lattice regenerative cooling structure, applied to the thrust chamber of a liquid rocket engine lattice regenerative cooling structure as claimed in claim 3, characterized in that: The following steps are involved: Step S1: Determine the overall structure of the liquid rocket engine thrust chamber according to the engineering overview; Step S2: determining that the lattice regenerative cooling structure is a truss lattice structure, selecting the truss lattice structure and determining a layout mode; Step S3: using computer-aided design software to design a three-dimensional model of the thrust chamber; Step S4: exporting the 3D model to an STL file, where the STL file represents the surface of the 3D model with a triangular mesh, which is convenient for subsequent 3D printing processing; Step S5: Selective laser melting is used to print the thrust chamber product, and post-processing is performed after printing is completed.

5. The design method of the thrust chamber of the lattice regenerative cooling structure of a liquid rocket engine according to claim 4, characterized in that: The specific process of step S2 is: Step S21: Select the manufacturing material, determine the side length of the Kagome, BCC, BCCZ, Truncated cube, kelvin cell, and FCC cell structure, and determine the wall thickness of the inner wall and the outer wall; Step S22: arbitrarily select a cell structure from among Kagome, BCC, BCCZ, Truncated cube, kelvin Cell, and FCC; Step S23: repeatedly arranging the selected cell structure in a three-dimensional space according to a set layout, thereby obtaining a lattice regenerative cooling structure.

6. The method for designing a thrust chamber of a liquid rocket engine lattice regenerative cooling structure according to claim 5, characterized in that: In the step S21, the selected manufacturing material is one of titanium alloy, nickel-based alloy and copper alloy.

7. The method for designing a thrust chamber of a liquid rocket engine lattice regenerative cooling structure according to claim 5, characterized in that: In step S22, the lattice cells of the six cell structures are as follows: The lattice cell of Kagome is the first equilateral triangle, which is periodic on the plane; six first equilateral triangles form a hexagon. The mathematical expression of Kagome is: the side length of the first equilateral triangle is b, and the coordinates of the three vertices are expressed as: (0,0), ( , ), (b,0), in three-dimensional space, the first equilateral triangle of the plane forms a three-dimensional Kagome structure through rotation and translation; The lattice cell of BCC is the first cube, and there is a first node at the center and eight corners of the first cube. The mathematical expression of BCC is: the side length of the first cube is a, the coordinates of the first node at the center of the first cube are (a / 2, a / 2, a / 2), and the coordinates of the first nodes at the eight corners of the first cube are (0, 0, 0), (a, 0, 0), (0, a, 0), (0, 0, a), (a, a, 0), (a, 0, a), (0, a, a) and (a, a, a) respectively. The lattice cell of BCCZ is based on the lattice cell of BCC. Z-shaped supports are added to the diagonal direction of the lattice cell of BCC, i.e., the first cube. The Z-shaped supports connect the specified vertices and central atoms in the lattice cell of BCC to form a mesh structure. The lattice cell of the truncated cube is the fourth cube. A small cube is cut off from each vertex of the fourth cube. The eight vertices of the fourth cube are cut off by small cubes to form a truncated cube. The lattice cell of Kelvin Cell is a regular octahedron, and the eight faces of the regular octahedron are all equilateral triangles. A regular octahedron is selected as the initial structure, and the regular octahedron is truncated, that is, the triangular vertices of the six vertices of the regular octahedron are cut off to form a plane. After the truncation operation, each vertex position of the regular octahedron becomes a square, and each face of the regular octahedron becomes a regular hexagon; thus, 6 square faces and 8 hexagonal faces are formed; finally, the side length ratio of the hexagonal face and the square face is adjusted to obtain a complete cell structure; The FCC lattice is a symmetrical crystal structure whose lattice cell is a second cube, called the basic cube. There is a second node at the center of each of the six faces and eight vertices of the basic cube. The side length of the basic cube is c, and the coordinates of the second nodes at the centers of the six faces of the basic cube are: (c / 2,0,0), (0,c / 2,0), (0,0,c / 2), (c,c / 2,0), (c,0,c / 2), (c,c,c); the coordinates of the second nodes at the eight vertices of the basic cube are: (0,0,0), (c,0,0), (0,c,0), (0,0,c), (c,c,0), (c,0,c), (0,c,c), (c,c,c).

8. The method for designing a thrust chamber of a liquid rocket engine lattice regenerative cooling structure according to claim 5, characterized in that: In step S23, the layout modes include circumferential layout, axial layout, spiral layout, grid layout, and gradient layout, and each layout mode is implemented separately.

9. The method for designing a thrust chamber of a liquid rocket engine lattice regenerative cooling structure according to claim 5, characterized in that: In step S23, the node spacing of the lattice regenerative cooling structure is designed with a gradient and gradually changes along the cooling channel direction, that is, the node spacing at the combustion chamber position in the cooling channel is consistent, and the node spacing gradually increases from the throat to the nozzle direction, so as to achieve cooling effects and mechanical performance optimization of different parts.

10. The method for designing a thrust chamber of a liquid rocket engine lattice regenerative cooling structure according to claim 5, characterized in that: In step S5, post-processing includes support structure removal, heat treatment, surface treatment, size correction and performance testing.

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