Multifunctional experimental device for acquiring ablation data of solid rocket engine under multiple conditions

Abstract

The invention discloses a multifunctional experimental device for acquiring ablation data of a solid rocket engine under multiple conditions, which comprises a combustion chamber section, a primary convergence section which is of a conical structure with a large upper opening and a small lower opening, an eddy current experimental section which is of an L-shaped cylindrical structure with a square cross section, and a secondary convergence section which is of a cylindrical structure with a large left end opening and a small right end opening, the left end is coaxial and mutually communicated with the right end of the transverse section of the eddy current experiment section, and the right end is sequentially communicated with a high-speed experiment section and an overload section which are inclined upwards from left to right; wherein the eddy current experiment section is used for generating eddy current in the eddy current experiment section and generating overload in the overload section after the eddy current passes through the high-speed experiment section, and then ablation data is obtained according to the ablation condition of each test piece; according to the invention, airflow vortex, high-speed fuel gas flow and fuel gas overload generated in the engine can be simulated at the same time, so that thermal insulation layer ablation data under various conditions can be obtained.

Description

Technical Field

[0001] This invention belongs to the field of rocket engine peripheral experiments, and in particular relates to a multifunctional experimental device for obtaining ablation data of solid rocket engines under multiple conditions. Background Technology

[0002] Solid rocket motor insulation layers operate in extremely harsh environments, enduring the ablation of high-temperature, high-pressure combustion gases and the erosion of condensed particles. Therefore, the ablation problem of insulation materials has always been a major concern. New-generation aircraft have increasingly higher requirements for maneuverability, and these aircraft must withstand high overloads during maneuvers. Currently, most solid rocket motors use aluminum-containing composite propellants. The combustion gases generated during engine operation contain a large number of alumina condensed particles, and the flow within the engine is a typical two-phase flow. High overloads can alter the motion patterns of these condensed particles, potentially leading to high localized aggregation and, in severe cases, failure of the inner insulation layer. In recent years, there have been frequent test failures in domestic flight tests and engine ground tests due to thermal protection failures, drawing significant attention.

[0003] Therefore, experimental research on the ablation of the insulation layer under different conditions of solid rocket motors can effectively increase the launch success rate and promote the development of high-performance solid rocket motors. However, existing experimental conditions often cannot simultaneously conduct ablation tests on the insulation layer considering two-phase flow vortices and condensed material deposition, high-speed two-phase flow scouring, and high overload conditions. It is difficult to obtain multiple sets of data from a single test, and independent tests are very costly in terms of manpower and financial resources. Summary of the Invention

[0004] The purpose of this invention is to provide a multifunctional experimental device for obtaining ablation data of solid rocket engines under multiple conditions, so as to solve the problem of high cost of insulation layer ablation test, and to obtain insulation layer ablation data under multiple conditions in one test.

[0005] This invention employs the following technical solution: a multifunctional experimental device for acquiring ablation data of solid rocket motors under multiple conditions, comprising:

[0006] The combustion chamber section is a cylindrical structure with a closed top, and the propellant is fixed inside it;

[0007] The first-stage convergence section is a conical structure with a larger opening at the top and a smaller opening at the bottom. Its upper opening is connected to and coaxially arranged with the combustion chamber section. It is used for the gas flow after propellant combustion to enter from the upper opening and exit from the lower opening, thereby accelerating the gas flow for the first time.

[0008] The eddy current test section is an L-shaped cylindrical structure with a square cross-section. Its top opening is coaxially arranged and interconnected with the lower opening of the first-stage convergence section. The specimen is placed at the bottom of its vertical section, and its horizontal section extends to the right, forming a eddy current at the junction of the vertical and horizontal sections.

[0009] The secondary convergence section is a cylindrical structure with a large opening at the left end and a small opening at the right end. Its left end is coaxial with and connected to the right end of the transverse section of the eddy current test section. Its right end is connected to the high-speed test section and the overload section, which slope upward from left to right.

[0010] The eddy test section is used to generate eddies in the airflow, and after passing through the high-speed test section, it generates overload in the overload section, thereby obtaining ablation data through the ablation of each specimen.

[0011] Furthermore, a support is installed inside the combustion chamber section, the support is horizontally positioned, and propellant is fixed to its lower side.

[0012] Furthermore, the high-speed test section consists of a first extension section, a high-speed section, and a second extension section, all with square cross-sections. The first extension section is horizontally positioned, with its left end coaxial with and connected to the right end of the second-order convergence section, and its right end connected to the high-speed section. The right end of the high-speed section is inclined upwards, and the angle between it and the axis of the first extension section is 45°. The second extension section is horizontally positioned, with its left end connected to the right end of the high-speed section, and the angle between the second extension section and the high-speed section is 45°. Specimens are placed on the lower sidewalls of both the first extension section and the high-speed section.

[0013] Furthermore, the overload section consists of a third extension section and an inclined section. The left end of the third extension section is coaxial with and connected to the right end of the second extension section. The left end of the inclined section is connected to the right end of the third extension section, and its right end is inclined upward. The angle between the third extension section and the inclined section is 45°. A test specimen is placed on the lower side wall of the inclined section.

[0014] The beneficial effects of this invention are:

[0015] This invention can acquire data on insulation layer ablation under two-phase flow vortex and condensed material deposition conditions within a solid rocket engine; it can also acquire data on insulation layer ablation under high-speed two-phase flow scouring conditions within a solid rocket engine; it can also acquire data on insulation layer ablation under high overload conditions within a solid rocket engine; and it can also acquire the pressure change curve of the internal flow field over time during the operation of the test engine through a pressure sensor installed in the combustion chamber section; this invention can simultaneously simulate airflow vortices, high-speed gas flow, and gas overload generated inside the engine, thereby obtaining insulation layer ablation data under various conditions. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention;

[0017] Figure 2 This is the engine computation domain of Embodiment 1 of the present invention;

[0018] Figure 3 This is a cloud map showing the distribution of condensed particle concentration on the engine center surface in Embodiment 1 of the present invention;

[0019] Figure 4 The curves showing the convective heat transfer changes of each heat transfer wall surface of the engine in Embodiment 1 of the present invention are shown.

[0020] Figure 5 The condensed particle trajectory of Example 1 of the present invention;

[0021] Figure 6 This is a streamline diagram of the gas phase flow field in Embodiment 1 of the present invention.

[0022] Among them: 10. Combustion chamber section; 11. First-stage convergence section; 12. Eddy test section; 13. Second-stage convergence section; 14. High-speed test section; 15. First extension section; 16. High-speed section; 17. Second extension section; 18. Overload section; 19. Third extension section; 20. Inclined section. Detailed Implementation

[0023] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0024] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "multiple" means two or more. The term "orientation" in this invention refers to the orientation of the device or element according to the invention. Figure 1 Description of the state's progression.

[0025] This invention discloses a multifunctional experimental apparatus for acquiring ablation data of solid rocket motors under multiple conditions, such as... Figure 1 As shown, it includes: combustion chamber section 10, first-stage convergence section 11, eddy current test section 12, and second-stage convergence section 13.

[0026] The combustion chamber section 10 is a cylindrical structure with a closed top, and the propellant is fixed inside the combustion chamber section 10; the first-stage convergent section 11 is a conical structure with a larger opening at the top and a smaller opening at the bottom. The upper opening of the first-stage convergent section 11 is connected to the combustion chamber section 10 and is coaxially arranged. The first-stage convergent section 11 is used for the airflow after the propellant combustion to enter from the upper opening and exit from the lower opening, thereby initially accelerating the airflow.

[0027] The eddy current test section 12 is an L-shaped cylindrical structure with a square cross-section. The top opening of the eddy current test section 12 is coaxially arranged and interconnected with the lower opening of the first-stage convergence section 11. The specimen is placed at the bottom of the vertical section of the eddy current test section 12. The horizontal section of the eddy current test section 12 extends to the right and forms a eddy at the junction of the vertical and horizontal sections.

[0028] The secondary convergence section 13 is a cylindrical structure with a large opening at the left end and a small opening at the right end. The left end of the secondary convergence section 13 is coaxial with and connected to the right end of the transverse section of the vortex test section 12. The right end of the secondary convergence section 13 is connected to the high-speed test section 14 and the overload section 18, which are inclined upward from left to right. The vortex test section 12 is used to generate vortices in the airflow, and after passing through the high-speed test section 14, it generates overload in the overload section 18, thereby obtaining ablation data through the ablation of each specimen.

[0029] A support frame is installed inside the combustion chamber section 10. The support frame is horizontally positioned and the propellant is fixed to its lower side.

[0030] The high-speed test section 14 consists of a first extension section 15, a high-speed section 16, and a second extension section 17, all with square cross-sections. The first extension section 15 is horizontally positioned, with its left end coaxial with and connected to the right end of the secondary convergence section 13, and its right end connected to the high-speed section 16. The right end of the high-speed section 16 is inclined upwards, and the angle between it and the axis of the first extension section 15 is 45°. The second extension section 17 is horizontally positioned, with its left end connected to the right end of the high-speed section 16, and the angle between the second extension section 17 and the high-speed section 16 is 45°. Specimens are placed on the lower sidewalls of both the first extension section 15 and the high-speed section 16.

[0031] The overload section 18 consists of a third extension section 19 and an inclined section 20. The left end of the third extension section 19 is coaxial with and connected to the right end of the second extension section 17. The left end of the inclined section 20 is connected to the right end of the third extension section 19, and its right end is inclined upward. The angle between the third extension section 19 and the inclined section 20 is 45°. A test specimen is placed on the lower side wall of the inclined section 20.

[0032] In this invention, the combustion chamber section serves as the gas generation device, where the propellant burns to provide high-temperature gas for the experiment. After flowing out of the combustion chamber section 10, the gas undergoes its first convergence acceleration in the primary convergence section. After the first acceleration, the gas flows out and forms a gas-phase vortex within the vortex experimental section 12. Under the influence of the vortex, the gas velocity decreases, and condensed matter in the gas will deposit in this region. The gas flowing out of the vortex experimental section 12 undergoes a second convergence acceleration in the secondary convergence section, and then passes through the high-speed experimental section and the overload section to reach the nozzle and be ejected. Therefore, the high-speed experimental section allows for the ablation experiment of the insulation material under high-speed gas conditions, and the overload section simulates the scouring effect of high-speed gas on the insulation material at different angles.

[0033] Example 1

[0034] Table 1 Summary of Particle Concentration in Engine Flow Field

[0035]

[0036] Table 2 Summary of Engine Wall Heat Transfer Characteristics

[0037]

[0038] Based on the parameter requirements in Tables 1 and 2, the combustion chamber section 10 is selected as a cylindrical structure with an inner diameter of 250mm, and is connected to the front end cap using M20 bolts. The combustion chamber section 10 is equipped with a pressure sensor interface, which can measure the rate of change of pressure over time during engine operation.

[0039] The convergence angle of the first-stage convergence section 11 is controlled between 30 and 40 degrees, which accelerates the gas flow within this channel. The gas velocity at the outlet of the first-stage convergence section 11 can be controlled by changing the regulating rings of different diameters. In the eddy current experimental section 12, the gas flow directions at the upper fluid inlet and outlet are distributed at a 90-degree angle. A distinct vortex backflow zone is formed at the bottom of the eddy current experimental section 12. An insulation layer specimen is attached to the bottom of the eddy current experimental section to observe and measure the ablation condition of the insulation layer specimen under the gas vortex and condensed particle deposition state. The convergence angle of the second-stage convergence section 13 is 15-25°.

[0040] After being accelerated through the secondary convergence section 13, the gas flows into the high-speed test section 14. The right end of the high-speed section 16 is inclined upwards, forming a 45° angle with the axis of the first extension section 15. The second extension section 17 also forms a 45° angle with the high-speed section 16. In the overload section 18, the third extension section 19 forms a 45° angle with the inclined section 20. The transverse section of the eddy current test section 12 is referred to as the low-speed section.

[0041] Table 3 Material Selection Table for Various Components of the Device

[0042]

[0043]

[0044] The parameters of the steel used are shown in Table 4.

[0045] Table 4 Steel Parameters

[0046]

[0047] The wall strength of the experimental device needs to be able to withstand a pressure of 30 MPa. Due to the different overall configuration of the device, the cavity cross-section is divided into two types: circular and square. The calculation methods for the two different cavities are different. The larger the cavity cross-section, the greater the pressure it can withstand. Here, the combustion chamber with the largest inner cross-sectional area in the circular type and the vortex experimental section 12 with the largest inner cross-sectional area in the square type are selected for wall strength verification.

[0048] Strength check of the circular cavity wall of the experimental setup:

[0049] For cylindrical cavities, the minimum wall thickness can be estimated based on the maximum stress intensity theory:

[0050]

[0051] In the formula:

[0052] p max —The maximum permissible working pressure of the container, in MPa;

[0053] δ min — Container wall thickness, mm;

[0054] [σ]——Allowable stress of the material, MPa;

[0055] D—Diameter of the mid-surface of the cylinder, mm;

[0056] Φ—Weld coefficient.

[0057] Based on the design dimensions, δ = 20mm, D = 250mm; the yield strength σ of the 30CrMnSiA steel used for the cylinder is... s =835MPa, safety factor S=3, then [σ]=σ s / S=278.3MPa,Φ=0.9.

[0058]

[0059] Therefore, a wall thickness of 20mm for combustion chamber section 10 here meets the design requirements.

[0060] Since the inner cross-section of the square cavity is square, the midpoint N and the corner point Q are taken as the calculation objects to calculate the stress at the two points.

[0061] The membrane stresses at points N and Q on the side plate are calculated using the following formula:

[0062]

[0063] The formulas for calculating the bending stress at points N and Q on the side plate are:

[0064]

[0065] In the formula:

[0066] p max —The maximum permissible working pressure of the container, in MPa;

[0067] h — Dimension of the inner side panel of the container, in mm;

[0068] δ—Container wall thickness, mm;

[0069] L s —The effective width of the reinforcing component that provides reinforcement, in mm;

[0070] I — Moment of inertia of the side plate, mm 4 ;

[0071] α, K — parameters.

[0072] Here, p max =30MPa, h=75mm, δ=20mm, then we can obtain:

[0073]

[0074] When there are no reinforcing components near the side plate, L s =1mm, the moment of inertia of the side plate is:

[0075]

[0076] When the cross-section is square, α = K = 1, therefore

[0077]

[0078] The formulas for calculating the bending stress at points N and Q are:

[0079]

[0080] Therefore, the wall thickness of 20mm for the eddy current test section 12 meets the strength requirements.

[0081] Two different bolt specifications were used for the bolt connections in the experimental setup: 24 sets of 10.9 grade M20×2.5 bolts were used to connect to the combustion chamber flange, and 10.9 grade M20×2.5 bolts were used to connect the other flanges. Here, the bolt strength was checked again on the combustion chamber section 10 and the eddy current test section 12 with the largest square inner cross-sectional area.

[0082] The flange at the combustion chamber can withstand a maximum pressure of 30MPa, with an inner diameter of D=250mm, and is connected by 24 sets of 10.9 grade M20×2.5 bolts.

[0083] If a bolt is subjected to an axial working load, then the maximum axial force that the bolt can withstand is:

[0084]

[0085] Select bolt grade 10.9, σ S =900MPa. Since the preload cannot be strictly controlled during assembly, a safety factor S = 2.5 is taken. The allowable stress of the bolt is:

[0086]

[0087] Equivalent stress of thread:

[0088]

[0089] The minor diameter d1 of the M20×2.5 bolt is 17.294 mm, therefore the strength of the bolt thread is:

[0090]

[0091] Strength check of 12 connecting bolts in the eddy current test section:

[0092] The eddy current test section 12 has a square cross-section with a side length of 75mm, a pressure resistance of 30MPa, and is connected by 16 sets of 10.9 grade M20×2.5 bolts.

[0093] If a bolt is subjected to an axial working load, then the maximum axial force that the bolt can withstand is:

[0094] F = 30 × 75 2 =168.75kN

[0095] Select bolt grade 10.9, σ S =900MPa. Since the preload cannot be strictly controlled during assembly, a safety factor S = 2.5 is taken. The allowable stress of the bolt is:

[0096]

[0097] Equivalent stress of thread:

[0098]

[0099] The minor diameter d1 of the M20×2.5 bolt is 17.294 mm, therefore the strength of the bolt thread is:

[0100]

[0101] Therefore, the strength of the bolts at the flange of the experimental device meets the design requirements.

[0102] The cross-sectional area of ​​the gas passage determines the gas flow density and directly affects the surface heat transfer coefficient between the gas and the wall. When the gas parameters are constant, the area of ​​the gas passage can be determined according to the similarity criterion. Here, the gas passage area of ​​the high-speed cavity is calculated based on the surface heat transfer coefficient of the high-speed section 16.

[0103] The average surface heat transfer coefficient of high-speed test section 14 is 1000 W / (m²). 2 ·K), the experimental setup is a face-fired charging method with a burning surface diameter of 230mm and a gas mass flow rate of 0.82kg / s. The known physical properties of the gas at the combustion temperature are: c p =3041J / (kg·K), λ=0.15W / (m·K), μ=8.1×10 -5 Pa·s. Ignoring erosion effects, and assuming the charge channel has a constant cross-section, the Nusselt number is expressed as:

[0104] Nu = 0.023Re 0.8 Pr 0.4

[0105] Substituting the definitions of Nusselt number, Reynolds number, and Prandtl number, we can see that:

[0106]

[0107] Rearranging the above equation, the surface heat transfer coefficient is:

[0108]

[0109] In the engine combustion chamber, the mass flow rate is

[0110]

[0111] In the formula: ρ p For propellant density; A b The combustion area between the charge head and the cross-section under study; For propellant burning rate.

[0112] At section x, we have A b =Π b Substituting x into the above equation, we get

[0113]

[0114] In practical calculations, the mass flow rate at the cross-section inside the combustion chamber can be approximated as:

[0115]

[0116] L p This is the length of the propellant charge. We can obtain...

[0117]

[0118] In engineering design, this can generally be simplified by using the average value of the convective heat transfer coefficient along the length at a certain moment. Instead of the convective heat transfer coefficient in the entire combustion chamber at that moment, i.e.

[0119]

[0120] Substituting the values ​​of each parameter, we get: K c =5.97, Π=π×230×10 -3 m.

[0121]

[0122] Solving for A, we get: A = 1.998 × 10 -3 m 2 The cross-section of the high-speed test section 14 is square, so its theoretically calculated side length is 44.7 mm. In the design, the side length of the cavity of the high-speed test section 14 is 45 mm.

[0123] Numerical simulation of the internal flow field of the experimental engine, such as Figure 2 As shown, this is the computational domain of the engine. The computational domain adopts a partitioned mesh generation technique, and numerical simulation studies are carried out under a working pressure of 20 MPa.

[0124] like Figure 3 The figure shows the distribution cloud map of condensed particle concentration on the center surface of the engine. It can be seen from the figure that the particles are mainly concentrated in eddy current experimental section 12, where some deposition occurs. The particle concentration at the heat transfer wall of high-speed experimental section 14 is 180 kg / m². 3 The particle concentration in overload section 18 is 76.5 kg / m³. 3 The speed in eddy current test section 12 is in the range of 0-12 m / s, the speed in low speed section is in the range of 9-12 m / s, the speed in high speed test section 14 is in the range of 25-27 m / s, and the speed in overload section 18 is in the range of 57-61 m / s.

[0125] like Figure 4The figure shows the convective heat transfer curves for each heat transfer wall surface of the engine. Since the operating pressure of this numerical simulation is 20 MPa, the heat transfer range of the engine can be referenced in Table 1 for the parameter ranges of each wall surface at times 6.5s and 18.9s for the φ700 engine, and at times 8.4s, 12.4s, and 19.8s for the φ1000 engine. Figure 4 It can be seen that the convective heat transfer coefficient of eddy test section 12 is between 52 and 436 (W / m). 2 The range of K) basically meets the experimental simulation requirements compared to the vortex heat transfer range for the corresponding operating conditions in Table 1; Figure 4 b shows that the convective heat transfer coefficient in the low-speed range is 190-574 (W / m). 2 The range of K) basically meets the experimental simulation requirements compared to the heat transfer range of the cylinder under the corresponding operating conditions in Table 1; Figure 4 c shows that the convective heat transfer coefficient of high-speed experimental section 14 is between 325 and 846 (W / m). 2 The range of K) is slightly smaller than the heat transfer range of the rear head corresponding to a velocity of 30 m / s in Table 1. The convective heat transfer coefficient at the wall surface is related not only to the flow velocity but also significantly to the flow state at the wall surface. The heat transfer range can be adjusted by adjusting the impact angle to meet the experimental simulation requirements. Figure 4 d shows that the convective heat transfer coefficient of overload section 18 is between 176 and 2332 (W / m²). 2 The range of K shows that the convective heat transfer coefficient at the wall increases significantly with the increase of flow velocity.

[0126] like Figure 5 The figure shows the particle trajectory distribution in the flow field inside the engine. As can be seen from the figure, most of the condensed particles exiting the propellant surface collide with the bottom surface of the vortex experimental section 12 after passing through the first-stage convergence section 11. After rebounding, they finally hit the upper wall of the low-speed section, and after rebounding from the walls of the experimental device, they are finally ejected from the nozzle. Figure 6 The diagram shows the streamlines of the flow field inside the engine. As can be seen from the diagram, the combustion gas exits from the propellant surface, flows through the first-stage convergent section 11, and exits through the flow channel along the low-speed section, while simultaneously forming vortices in the cavity of the vortex experimental section 12.

[0127] In summary, this invention can meet the requirements for considering a wide range of vortex heat transfer, heat transfer at different scouring velocities, heat transfer under different flow states, and ablation characteristics of insulation layers under different condensed particle scouring states. It has extensive functions, simple and convenient experimental operation, and can achieve multi-purpose ablation test research through the combination of different test section configuration parameters.

[0128] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multifunctional experimental apparatus for acquiring ablation data of solid rocket motors under multiple conditions, characterized in that, include: The combustion chamber section (10) is a cylindrical structure with a closed top, and propellant is fixed inside it; The first-stage convergence section (11) is a conical structure with a large upper opening and a small lower opening. Its upper opening is connected to the combustion chamber section (10) and is coaxially arranged. It is used for the gas flow after propellant combustion to enter from the upper opening and exit from the lower opening, thereby accelerating the gas flow for the first time. The eddy test section (12) is an "L"-shaped cylindrical structure with a square cross-section. Its top opening is coaxially connected with the lower opening of the first-level convergence section (11). The specimen is placed at the bottom of its vertical section, and its horizontal section extends to the right, forming a eddy at the junction of the vertical and horizontal sections. The secondary convergence section (13) is a cylindrical structure with a large opening at the left end and a small opening at the right end. Its left end is coaxial with and connected to the right end of the transverse section of the eddy current test section (12). Its right end is connected to the high-speed test section (14) and the overload section (18) that slope upward from left to right. The vortex test section (12) is used to generate vortices in the airflow, and after passing through the high-speed test section (14), it generates overload in the overload section (18), thereby obtaining ablation data through the ablation of each specimen.

2. The multifunctional experimental apparatus for acquiring ablation data of solid rocket motors under multiple conditions according to claim 1, characterized in that, A support is installed inside the combustion chamber section (10), the support is horizontally set, and propellant is fixed on its lower side.

3. The multifunctional experimental apparatus for acquiring ablation data of solid rocket motors under multiple conditions according to claim 1, characterized in that, The high-speed experimental section (14) consists of a first extension section (15), a high-speed section (16), and a second extension section (17), all of which have square cross sections. The first extension section (15) is horizontally arranged, and its left end is coaxial with and connected to the right end of the secondary convergence section (13). Its right end is connected to the high-speed section (16). The right end of the high-speed section (16) is inclined upward and forms an angle of 45° with the axis of the first extension section (15). The second extension section (17) is horizontally arranged, and its left end is connected to the right end of the high-speed section (16). The angle between the second extension section (17) and the high-speed section (16) is 45°. Specimens are provided on the lower sidewall of the first extension section (15) and the lower sidewall of the high-speed section (16).

4. The multifunctional experimental apparatus for acquiring ablation data of solid rocket motors under multiple conditions according to claim 1, characterized in that, The overload section (18) consists of a third extension section (19) and an inclined section (20). The left end of the third extension section (19) is coaxial with and connected to the right end of the second extension section (17). The left end of the inclined section (20) is connected to the right end of the third extension section (19), and its right end is inclined upward. The angle between the third extension section (19) and the inclined section (20) is 45°. A test specimen is provided on the lower side wall of the inclined section (20).

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