Plasma scouring particle preparation and optimization method based on solid rocket engine working condition calibration

Abstract

The invention relates to a plasma scouring particle preparation and optimization method based on solid rocket engine working condition calibration, and belongs to the field of plasma ablation. The method comprises the following steps: sampling from a specified part of a target solid rocket engine, observing and recording the section diameter of the tail end of a fiber after the material is ablated, and recording as D1; the preparation method comprises the following steps: by taking aluminum oxide powder as a main raw material, doping carbon powder with a certain mass ratio w, mixing, and then carrying out ball milling for a ball milling time t, so as to obtain primarily prepared washing particles; spraying out the prepared scouring particles and plasma flames together, and carrying out an ablation scouring test on a sample; the included angle alpha 2 between the sample and the plasma flame is consistent with the included angle alpha 1 between the fuel gas and the calibration part in the actual working condition of the engine; observing the diameter of the cross section of the tail end of the fiber on the surface of the ablated sample, recording as D2, and calculating the ratio c of D2 to D1, wherein c = D2 / D1; and performing iterative optimization. According to the invention, the precision degree of simulating the working condition of the solid rocket engine in the plasma ablation scouring process is improved.

Description

Technical Field

[0001] This invention belongs to the field of plasma ablation, specifically relating to a method for preparing and optimizing particles for plasma scouring based on solid rocket engine operating condition calibration. Background Technology

[0002] Composite materials are widely used in solid rocket motors. In predicting the ablation of these materials, plasma ablation is needed to simulate the actual ablation and scouring process. During the actual scouring process of a solid rocket motor, the condensed particles in the combustion gas are liquefied aluminum and alumina particles. Currently, there is little publicly available information on particle preparation methods used for this ablation and scouring process. The scouring particles in wind tunnel ablation are also mainly alumina particles, making it difficult to simulate the particle performance under actual operating conditions. This limits the application of plasma ablation methods in the ablation prediction and design of solid rocket motors.

[0003] Currently, the evaluation indicators for fitting methods of the scouring process in the field are mainly based on linear ablation rate and mass ablation rate. However, there are no detailed evaluation indicators for the particle scouring process in plasma ablation. As a result, the particle scouring process can only be fitted by its ejection velocity. In reality, solid rocket motors operate under a variety of conditions, and the particle scouring process of ablation is different under different conditions and at different locations. Not only is the preparation method of scouring particles mentioned above needed, but also a way to quantitatively evaluate and compare the scouring effect in order to promote the optimization of process parameters in the preparation of scouring particles.

[0004] However, existing plasma erosion simulation methods suffer from two major technical bottlenecks: First, the simulation of erosion particles lacks realism. During solid rocket motor operation, the condensed particles produced by propellant combustion are not simply alumina (Al2O3), but rather composite particles composed of droplets of aluminum and its oxidation product, Al2O3. These particles differ significantly from the standard alumina particles with a single composition commonly used in current plasma ablation tests in terms of hardness, melting point, thermophysical properties, and interaction mechanisms with material surfaces. For example, existing technologies use Al2O3 particles for erosion resistance testing, but their particle preparation methods do not consider the simulation of real engine condensed particles. This results in test results that only reflect the erosion resistance of a single material, failing to reproduce the coupling effect between the "thermal increment" effect of aluminum droplets and the "mechanical ablation" effect of alumina particles under actual operating conditions.

[0005] Second, a calibration and optimization system for ablation results is lacking. Existing technologies disclose the process parameters (such as heat flux density and particle velocity) for calibrating the ablation equipment itself. However, even if the macroscopic results are barely consistent through repeated adjustments of the equipment parameters, the particles used do not match real particles, and the simulated physical mechanism may be incorrect. This could lead to parameters that are calibrated under one operating condition becoming completely ineffective when using a different material or engine, resulting in low universality and value for mechanistic research.

[0006] Therefore, developing a method that can prepare highly realistic erosion particles and quantitatively optimize the particle preparation process based on ablation results is of vital engineering significance for improving the accuracy of ablation prediction for solid rocket motor composite materials. Summary of the Invention

[0007] The technical problem to be solved: To avoid the shortcomings of existing technologies, this invention provides a method for preparing and optimizing plasma erosion particles based on solid rocket motor operating condition calibration. The purpose is to provide a method for preparing erosion particles and a corresponding method for quantifying the erosion results, so as to optimize the preparation parameters of Al2O3 particles and make the erosion results as consistent as possible with the actual operating conditions of solid rocket motors.

[0008] The technical solution of this invention is: a method for preparing and optimizing particles for plasma scouring based on solid rocket motor operating condition calibration, comprising the following steps: Step 1: Determine the calibration index: Take a sample from a designated part of the target solid rocket motor, observe and record the cross-sectional diameter of the fiber ends after the material is ablated, and denot it as D1; Step 2, Initial particle preparation: Alumina powder is used as the main raw material, and carbon powder of a certain mass ratio w is added. After mixing, the mixture is ball-milled for a time of t to obtain the initially prepared scouring particles. Step 3, Plasma ablation test: The scouring particles prepared in step 2 are sprayed out together with the plasma flame to conduct an ablation scouring test on the sample; the angle α2 between the sample and the plasma flame is consistent with the angle α1 between the combustion gas and the calibration part in the actual working condition of the engine. Step 4: Comparison of test results: Observe the diameter of the fiber end section on the surface of the ablation sample, denoted as D2, and calculate its ratio with D1, c = D2 / D1; Step 5, Iterative optimization: Use whether the value of c falls within the preset target range [0.9, 1.1] as the criterion; If the value of c does not fall within the target range, adjust the ball milling time t and / or carbon powder mass ratio w in step two according to the value of c, and return to step two for a new round of particle preparation and verification. If the value of c falls within the target range, it is determined that the currently prepared scouring particles can be used to simulate the material regression under the coupled processes of oxidation reaction, particle collision erosion, particle swarm effect, and heat transfer under the operating conditions of the target solid rocket engine. A further technical solution of the present invention is: in step two, the mass ratio w of the toner is in the range of 1% to 5% when it is first prepared.

[0009] A further technical solution of the present invention is: in step two, the ball milling time t is initially configured to be 1 hour.

[0010] A further technical solution of the present invention is: the single adjustment amount of the ball milling time t is 0.25 hours to 0.5 hours.

[0011] A further technical solution of the present invention is: in step five, the specific logic of the iterative optimization is as follows: When c < 0.9, reduce the ball milling time t; When c > 1.1, increase the ball milling time t.

[0012] A further technical solution of the present invention is: after the ball milling time t is adjusted for the first time, if the trend of the change of the c value does not reverse, the mass ratio w of the carbon powder is increased to the range of 6% to 10%, and the adjustment and optimization are continued.

[0013] A further technical solution of the present invention is: in step two, the initial particle size of the alumina powder is 110 mesh, and the initial particle size of the carbon powder is 35 mesh.

[0014] A composite particle for plasma scouring in solid rocket motor operating condition simulation, wherein the composite particle is composed of alumina powder and carbon powder through a ball milling process, wherein the mass fraction of carbon powder is 1% to 10%; The particle size distribution and morphology of the composite particles are controlled by ball milling time, so that when the particles are used to perform plasma ablation erosion tests on standard samples, the ratio c of the fiber end cross-sectional diameter D2 on the surface of the ablated sample to the fiber end cross-sectional diameter D1 of the actual debris from the target solid rocket motor satisfies: 0.9≤c≤1.1.

[0015] A plasma erosion test system for calibrating the operating conditions of solid rocket engines includes: The particle preparation unit is used to mix alumina powder and carbon powder in a predetermined ratio and then ball-mill them to prepare composite particles for rinsing. The plasma ablation apparatus is equipped with a powder feeder, which is used to spray the composite particles prepared by the particle preparation unit together with the plasma flame to ablate and scour the sample clamped on the sample stage. The morphology observation and analysis unit is used to acquire and analyze the surface micromorphology of the sample after ablation, and to measure the diameter D2 of the fiber end section. The data processing and feedback control unit is configured as follows: Receive D2 data from the topography observation and analysis unit, and call up the pre-stored fiber end cross-section diameter D1 from the actual solid rocket motor debris; Calculate the calibration ratio c = D2 / D1; Determine whether the value of c falls within the preset target interval [0.9, 1.1]; If the c-value does not fall within the target range, a control command is generated to adjust the ball milling time and / or carbon powder mixing ratio in the particle preparation unit to start a new round of particle preparation and testing until the c-value falls within the target range.

[0016] A solid rocket motor operating condition simulation system is provided, which uses scouring particles prepared and optimized by the method described above to conduct ground simulation tests on the ablation performance of hot-end components of the engine.

[0017] Beneficial effects The beneficial effects of this invention are as follows: the particles prepared by this method can subject ablation samples to a particle erosion environment similar to that of solid rocket motors, particularly in terms of physical ablation and the thermal increase caused by particles, thus making the plasma erosion ablation environment closer to actual operating conditions. Compared with conventional methods, this method can conduct single-item verification experiments on material samples using particle erosion testing, evaluate the thermal effects caused by erosion, and provide a reference for ablation prediction under various solid rocket motor operating conditions. Specific effects are analyzed as follows: 1. This invention overcomes the limitations of existing technologies that rely solely on alumina particles by preparing composite particles of alumina and carbon powder. The addition of carbon powder more realistically simulates the characteristics of incompletely oxidized aluminum droplets or their transformation intermediates in actual solid rocket motors. This allows the plasma scouring process to not only reproduce mechanical erosion but also better simulate the additional thermochemical effects ("heat increment") brought by the particles. Thus, at the coupling level of the four key processes—oxidation reaction, particle collision erosion, particle swarm effect, and heat transfer—a high degree of fit to the actual operating conditions of the engine is achieved.

[0018] 2. Existing technologies mostly rely on macroscopic indicators such as ablation rate and back temperature for calibration. These indicators are the comprehensive results of multiple coupled effects, and their directionality is ambiguous. This invention innovatively proposes to use the ratio of the cross-sectional diameter of the fiber end of the ablated material (c = D2 / D1) as the core calibration indicator.

[0019] 3. This invention links the four stages of "particle preparation—ablation test—result comparison—parameter optimization" into a complete, dynamic feedback optimization closed loop. The system can automatically and intelligently adjust key parameters of particle preparation (ball milling time t, carbon powder ratio w) based on the results (c-value) of each test, ensuring that the performance of the prepared particles continuously approaches the target requirements. This method transforms particle preparation from a static, experience-dependent, "one-off" process into a dynamic, data-driven, "iterative optimization" process, significantly improving the optimization efficiency and simulation accuracy of the final particles.

[0020] 4. This invention directly addresses the fundamental deficiency of existing technologies, namely the mismatch in physicochemical properties between simulated and real particles. By actively optimizing and customizing the erosion particles, the correctness of the physical mechanism in the simulation experiment is ensured. This allows the ablation test results based on this method not only to be used for relative material ranking but also for in-depth research on the ablation mechanism of materials under complex service environments, providing reliable data support and theoretical guidance for the design of new materials and the precise design of engines. Attached Figure Description

[0021] Figure 1 This is a schematic diagram illustrating the implementation of the plasma scouring particle preparation and optimization method based on solid rocket engine operating condition calibration in this embodiment of the invention. Detailed Implementation

[0022] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0023] While existing technologies (such as CN119715661A) propose calibrating the plasma ablation process using macroscopic parameters such as ablation rate and back temperature, their calibration targets the process parameters of the ablation equipment itself (such as heat flux density and particle velocity), without addressing the preparation process of the ablation particles. In other words, existing methods lack a feedback optimization closed loop that directly links the "ablation results" with the "particle preparation parameters." When there are discrepancies between the ablation simulation results and the analysis of actual engine debris, those skilled in the art lack clear guidance to adjust and optimize the characteristics of the ablation particles (such as particle size, composition, and morphology), and can only blindly adjust the equipment operating conditions. This makes it difficult to fundamentally improve the accuracy of plasma ablation tests and their fit to the actual engine operating conditions.

[0024] To address the problems existing in the aforementioned technologies, this invention proposes a method for preparing and optimizing plasma scouring particles based on solid rocket engine operating condition calibration. Essentially, it establishes a dynamic closed-loop system of "preparation-experimentation-comparison-optimization," enabling the laboratory-prepared scouring particles to accurately simulate real engine operating conditions through iterative feedback. The method includes the following steps: Step 1: Determine the calibration index: Take a sample from a designated part of the target solid rocket motor, observe and record the cross-sectional diameter of the fiber ends after the material is ablated, and denot it as D1; Step 2, Initial particle preparation: Alumina powder is used as the main raw material, and carbon powder of a certain mass ratio w is added. After mixing, the mixture is ball-milled for a time of t to obtain the initially prepared scouring particles. Step 3, Plasma ablation test: The scouring particles prepared in step 2 are sprayed out together with the plasma flame to conduct an ablation scouring test on the sample; the angle α2 between the sample and the plasma flame is consistent with the angle α1 between the combustion gas and the calibration part in the actual working condition of the engine. Step 4: Comparison of test results: Observe the diameter of the fiber end section on the surface of the ablation sample, denoted as D2, and calculate its ratio with D1, c = D2 / D1; Step 5, Iterative optimization: Use whether the value of c falls within the preset target range [0.9, 1.1] as the criterion; If the value of c does not fall within the target range, adjust the ball milling time t and / or carbon powder mass ratio w in step two according to the value of c, and return to step two for a new round of particle preparation and verification. If the value of c falls within the target range, it is determined that the currently prepared scouring particles can be used to simulate the material regression under the coupled processes of oxidation reaction, particle collision erosion, particle swarm effect, and heat transfer under the operating conditions of the target solid rocket engine. This invention also proposes a composite particle for plasma scouring in the simulation of solid rocket engine operating conditions. The composite particle is formed by ball milling alumina powder and carbon powder, wherein the mass fraction of carbon powder is 1% to 10%. The particle size distribution and morphology of the composite particles are controlled by ball milling time, so that when the particles are used to perform plasma ablation erosion tests on standard samples, the ratio c of the fiber end cross-sectional diameter D2 on the surface of the ablated sample to the fiber end cross-sectional diameter D1 of the actual debris from the target solid rocket motor satisfies: 0.9≤c≤1.1.

[0025] This invention also proposes a plasma scouring test system for calibrating the operating conditions of solid rocket engines, comprising: The particle preparation unit is used to mix alumina powder and carbon powder in a predetermined ratio and then ball-mill them to prepare composite particles for rinsing. The plasma ablation apparatus is equipped with a powder feeder, which is used to spray the composite particles prepared by the particle preparation unit together with the plasma flame to ablate and scour the sample clamped on the sample stage. The morphology observation and analysis unit is used to acquire and analyze the surface micromorphology of the sample after ablation, and to measure the diameter D2 of the fiber end section. The data processing and feedback control unit is configured as follows: Receive D2 data from the topography observation and analysis unit, and call up the pre-stored fiber end cross-section diameter D1 from the actual solid rocket motor debris; Calculate the calibration ratio c = D2 / D1; Determine whether the value of c falls within the preset target interval [0.9, 1.1]; If the c-value does not fall within the target range, a control command is generated to adjust the ball milling time and / or carbon powder mixing ratio in the particle preparation unit to start a new round of particle preparation and testing until the c-value falls within the target range.

[0026] The present invention also proposes a solid rocket engine operating condition simulation system, which uses the scouring particles prepared and optimized by the method described above to conduct ground simulation tests on the ablation performance of the hot-end components of the engine.

[0027] The above technical solution will be further analyzed below with reference to the accompanying drawings and examples: In one embodiment, refer to Figure 1 As shown, the overall implementation process of this method is as follows: Step 1. Determine the calibration benchmark (determine the microstructure characteristics of materials under solid rocket engine operating conditions). Ablated debris or specimens are obtained from specific parts of the target solid rocket motor (such as the nozzle throat liner, submersion section, etc.) that require fitting. Samples are taken from these parts, and the ablated surface is observed using a scanning electron microscope, with a focus on measuring the cross-sectional diameter of exposed and fractured fiber ends in the composite material. Multiple fibers are randomly measured, and the statistical average is taken as the true ablation morphology characteristic value of this part, denoted as D1. Simultaneously, the angle between the surface of this part and the direction of the engine exhaust flow is recorded, denoted as α1.

[0028] Step 2. Initial particle preparation (method for preparing flushing particles) Raw material selection and proportioning: Industrial-grade alumina (Al2O3) powder with a particle size of 110 mesh is selected as the matrix. Graphite powder (carbon powder) with a particle size of 35 mesh is selected as the functional additive. For the initial formulation, the mass fraction w1 of the carbon powder is recommended to be between 1% and 5%.

[0029] Mixing and ball milling: The weighed alumina powder and carbon powder are placed in a ball mill jar, and an appropriate amount of zirconia balls of the correct size ratio are added as the ball milling media. Mechanical ball milling is performed, with the initial milling time t1 set to 1 hour. This process aims to thoroughly mix and break down the particles, bringing their particle size distribution and morphology to an initial, controllable state.

[0030] Sieving and collection: After ball milling, the mixture is sieved and powder of the required particle size range is collected to obtain the initially prepared scouring particles.

[0031] Step 3. Plasma ablation test (ablation erosion test) Sample preparation: Prepare a standard sample made of the same material as the engine calibration part, usually a disc with a diameter of 30 mm and a thickness of 10 mm.

[0032] Experimental setup: The sample was mounted on the sample stage of the plasma ablation equipment, and the sample orientation was adjusted so that the angle α2 between the eroded surface and the plasma flame was strictly equal to α1 recorded in step 1. The erosion particles prepared in step 2 were loaded into the powder feeder.

[0033] Ablation test: The plasma equipment is activated, and under the set basic parameters such as heat flux and gas pressure, the erosion particles and plasma flame are sprayed together onto the sample surface to conduct an ablation test. The ablation time can be set according to the actual operating time of the engine.

[0034] Step 4. Comparison of test results (comparison of particle scouring results after the test) After the experiment, once the sample had cooled sufficiently, a sample was taken from the center region of the ablated surface. The surface morphology was observed using SEM, and the cross-sectional diameter of the fiber ends after ablation was measured. The statistical average was recorded as D2. The calibration ratio c = D2 / D1 was calculated for this experiment.

[0035] Step 5. Iterative optimization (method for adjusting the preparation process) The calibration ratio c is used as the criterion for judgment and optimization: Case A: The c value falls within the range → This indicates that the currently prepared particles can accurately simulate the target working condition, and the optimization is complete. This batch of particles and the corresponding preparation parameters (w, t) can be used for subsequent simulation experiments under this working condition.

[0036] Case B: The value of c does not fall within the range → Enter the feedback optimization loop.

[0037] First priority: Adjust the ball milling time (t) If c < 0.9, it indicates that the simulated erosion is too weak (the fiber cross-section is too small). The ball milling time should be reduced, for example by 0.5 hours, to make the particles coarser and the edges more distinct, so as to enhance mechanical erosion.

[0038] If c > 1.1, it indicates that the simulated erosion is too strong (the fiber cross-section is too large). The ball milling time should be increased, for example, to 1.5 hours, to make the particles finer and smoother, so as to reduce the erosion intensity.

[0039] Return to step 2, use the adjusted ball milling time t2, but keep the carbon powder ratio w1 unchanged, and prepare particles again.

[0040] Second priority: Adjust the toner ratio (w) If, after adjusting the grinding time and conducting a new round of tests, the trend of the c-value does not reverse or still does not enter the target range (e.g., the c-value is still too small or too large), then the adjustment of the toner ratio should be initiated.

[0041] Generally, if the scouring intensity is consistently insufficient (c remains too low), the proportion of carbon powder can be increased to a range of 6% to 10%. By utilizing the reaction and ablation characteristics of carbon powder at high temperatures, the overall scouring behavior of the particles can be altered.

[0042] Return to step 2 and re-prepare particles using the new toner ratio w2 and the previously optimized ball milling time t2.

[0043] Repeat steps 2 through 3, 4, and 5 until the value of c stabilizes within the range of 0.9 to 1.1, marking the successful convergence of the optimization loop.

[0044] In one embodiment, the preparation of scouring particles for the vertical surface of the C / C composite material front end of an engine nozzle under operating conditions includes the following steps: Step 1. Determine the calibration benchmark: Take a sample from the vertical plane of the front end of the C / C composite material of the engine nozzle, and measure the average diameter D1 of the fiber end cross section under SEM. Record the gas flow angle α1 = 90°.

[0045] Step 2. Initial particle preparation: Mix 110-mesh alumina and 35-mesh graphite powder at a ratio of w1 = 3%, and ball mill for t1 = 1 h to obtain the first particles.

[0046] Step 3. Plasma ablation test: Prepare C / C composite material samples, set the ablation angle α2 = α1 = 90°, and perform ablation.

[0047] Step 4. Comparison of test results: D2 was measured after ablation, and c was calculated to be 1.5.

[0048] Step 5. Iterative optimization: First optimization: Due to the large c value, it was decided to increase the ball milling time. The ball milling time was adjusted to t2=1.5 h, while the carbon powder ratio remained unchanged (w1=3%), to prepare the second batch of particles.

[0049] Second test and comparison: D3 was measured after re-ablation, and c = D3 / D1 = 1.05 was calculated.

[0050] Results: The c-value fell within the range of 0.9 to 1.1, indicating successful optimization. The prepared powder was deemed capable of accurately simulating the particle scouring process in this engine component.

[0051] In one embodiment, the preparation of plasma scouring particles at the outlet of the expansion section of a resin composite material submerged in an engine nozzle involves the following specific steps: Step 1. Determine the calibration benchmark: Take a sample at the outlet position of the resin composite expansion section of the submerged nozzle of an engine and record the fiber ablation cross-section D1. The angle α1 between its position and the direction of gas flow is 30°.

[0052] Step 2. Initial particle preparation: Alumina particles with a particle size of 110 mesh are mixed with graphite powder of 35 mesh, wherein the mass percentage of graphite powder is w=5%. The mixture is ball-milled with zirconia for 1 hour to obtain the first-stage scouring particles.

[0053] Step 3. Plasma ablation test: Prepare resin composite material samples and set the ablation angle α2 = α1 = 30°.

[0054] Step 4. Comparison of test results: After ablation, the cross-sectional diameter D2 of the fiber was measured, and c was calculated to be 0.6.

[0055] Step 5. Iterative optimization: First optimization: Due to the small c value, the ball milling time was reduced to t2=0.5h, while the carbon powder ratio remained unchanged (w1=5%).

[0056] Second test and comparison: After ablation, the fiber cross-sectional diameter D3 was measured, and c was calculated to be 0.8 (still less than 0.9).

[0057] Second optimization: Since adjusting the ball milling time still didn't yield ideal results, the carbon powder ratio was increased. The carbon powder ratio was increased to w2=8%, while the ball milling time was maintained at t2=0.5 h, to prepare the third batch of particles.

[0058] Third test and comparison: After ablation, the fiber cross-sectional diameter D4 was measured, and c=1 was calculated.

[0059] Result: The c-value fell within the target range, indicating successful optimization. The prepared powder was deemed capable of accurately simulating this working condition.

[0060] In one embodiment, a composite particle for plasma scouring in solid rocket motor operating condition simulation is provided, wherein the composite particle is formed by ball milling alumina powder and carbon powder, wherein the mass fraction of carbon powder is 8%; The particle size distribution and morphology of the composite particles are controlled by ball milling time, so that when the particles are used to perform plasma ablation erosion tests on standard samples, the ratio c of the fiber end cross-sectional diameter D2 on the surface of the ablated sample to the fiber end cross-sectional diameter D1 of the actual debris from the target solid rocket motor satisfies: 0.9≤c≤1.1.

[0061] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A method for preparing and optimizing particles for plasma scouring based on solid rocket motor operating condition calibration, characterized in that, Includes the following steps: Step 1: Determine the calibration index: Take a sample from a designated part of the target solid rocket motor, observe and record the cross-sectional diameter of the fiber ends after the material is ablated, and denot it as D1; Step 2, Initial particle preparation: Alumina powder is used as the main raw material, and carbon powder of a certain mass ratio w is added. After mixing, the mixture is ball-milled for a time of t to obtain the initially prepared scouring particles. Step 3, Plasma ablation test: The scouring particles prepared in step 2 are sprayed out together with the plasma flame to conduct an ablation scouring test on the sample; the angle α2 between the sample and the plasma flame is consistent with the angle α1 between the combustion gas and the calibration part in the actual working condition of the engine. Step 4: Comparison of test results: Observe the diameter of the fiber end section on the surface of the ablation sample, denoted as D2, and calculate its ratio with D1, c = D2 / D1; Step 5, Iterative optimization: Use whether the value of c falls within the preset target range [0.9, 1.1] as the criterion; If the value of c does not fall within the target range, adjust the ball milling time t and / or carbon powder mass ratio w in step two according to the value of c, and return to step two for a new round of particle preparation and verification. If the value of c falls within the target range, it is determined that the currently prepared scouring particles can be used to simulate the material regression under the coupled processes of oxidation reaction, particle collision erosion, particle swarm effect, and heat transfer under the operating conditions of the target solid rocket engine.

2. The method for preparing and optimizing particles for plasma flushing based on solid rocket motor operating condition calibration according to claim 1, characterized in that: In step two, the mass ratio w of the toner initially ranges from 1% to 5%.

3. The method for preparing and optimizing particles for plasma flushing based on solid rocket motor operating condition calibration according to claim 2, characterized in that: In step two, the ball milling time t is initially set to 1 hour.

4. The method for preparing and optimizing particles for plasma flushing based on solid rocket motor operating condition calibration according to claim 3, characterized in that: The single adjustment increment for the ball milling time t is 0.25 hours to 0.5 hours.

5. The method for preparing and optimizing particles for plasma flushing based on solid rocket motor operating condition calibration according to claim 1, characterized in that: In step five, the specific logic of iterative optimization is as follows: When c < 0.9, reduce the ball milling time t; When c > 1.1, increase the ball milling time t.

6. The method for preparing and optimizing particles for plasma flushing based on solid rocket motor operating condition calibration according to claim 2, characterized in that: If the trend of the c value does not reverse after the initial adjustment of the ball milling time t, then the mass ratio of carbon powder w is increased to the range of 6% to 10%, and further adjustments and optimizations are made.

7. The method for preparing and optimizing particles for plasma flushing based on solid rocket motor operating condition calibration according to claim 1, characterized in that: In step two, the initial particle size of the alumina powder is 110 mesh, and the initial particle size of the carbon powder is 35 mesh.

8. A composite particle for plasma scouring in solid rocket motor operating condition simulation, prepared by the method described in any one of claims 1-7; characterized in that, The composite particles are formed by ball milling alumina powder and carbon powder, wherein the mass fraction of carbon powder is 1% to 10%. The particle size distribution and morphology of the composite particles are controlled by ball milling time, so that when the particles are used to perform plasma ablation erosion tests on standard samples, the ratio c of the fiber end cross-sectional diameter D2 on the surface of the ablated sample to the fiber end cross-sectional diameter D1 of the actual debris from the target solid rocket motor satisfies: 0.9≤c≤1.

1.

9. A plasma flushing test system for calibrating the operating conditions of a solid rocket motor, used to implement the method described in any one of claims 1-7; characterized in that, include: The particle preparation unit is used to mix alumina powder and carbon powder in a predetermined ratio and then ball-mill them to prepare composite particles for rinsing. The plasma ablation apparatus is equipped with a powder feeder, which is used to spray the composite particles prepared by the particle preparation unit together with the plasma flame to ablate and scour the sample clamped on the sample stage. The morphology observation and analysis unit is used to acquire and analyze the surface micromorphology of the sample after ablation, and to measure the diameter D2 of the fiber end section. The data processing and feedback control unit is configured as follows: Receive D2 data from the topography observation and analysis unit, and call up the pre-stored fiber end section diameter D1 from the actual solid rocket motor debris; Calculate the calibration ratio c = D2 / D1; Determine whether the value of c falls within the preset target interval [0.9, 1.1]; If the c-value does not fall within the target range, a control command is generated to adjust the ball milling time and / or carbon powder mixing ratio in the particle preparation unit to start a new round of particle preparation and testing until the c-value falls within the target range.

10. A solid rocket motor operating condition simulation system, characterized in that, The system uses scouring particles prepared and optimized by any one of claims 1-7 to conduct ground simulation tests on the ablation performance of hot-end components of an engine.

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