Step heating design method and device for simulating ballistic ablation response and medium

Abstract

The invention provides a step heating design method and device for simulating ballistic ablation response and a medium, and the method comprises the steps: obtaining a target response parameter in a flight ballistic environment, determining a heating time length, debugging a test state, and carrying out ablation thermal response trial calculation, and preparing an initial simulation ablation retreat amount and a simulation key position highest temperature for iterative calculation. Step heating state parameters of the ground simulation test are determined through iterative calculation on the basis of the target response parameters, and the first iteration step is used for determining the total enthalpy coefficient of the total enthalpy of the ground incoming flow with the matched target ablation retreat amount as the target; and the second iteration step takes the highest temperature of the matched target key position as a target and is used for determining a heat flux density coefficient of the ground heat flux density. According to the technical scheme, the total heating amount, the ablation amount and the highest temperature response of the key position in the step heating state can be completely matched with the response parameters in the flight trajectory state.

Description

Technical Field

[0001] This document relates to the field of aircraft thermal protection design technology, and in particular to a step heating design method, equipment and medium for simulating ballistic ablation response. Background Technology

[0002] Thermal protection technology is a hot research topic in the field of aerodynamics. Lightweight, efficient, and reliable are important directions for the development of future aircraft thermal protection systems, and also a huge challenge that traditional aircraft thermal protection technologies must face. Using ground tests to simulate the thermal response of thermal protection structures or thermal protection materials under the aerodynamic heating environment of flight ballistics is of great significance for the thermal protection design and optimization of aircraft.

[0003] Due to limitations in ground heating equipment capabilities or development costs, existing technologies mostly employ stepped heating to approximate or equivalently simulate the aerodynamic heating environment of flight ballistics. Ground-based tests simulating the thermal response of heat protection structures or materials under flight ballistic heating environments primarily fall into two categories: one uses peak heat flux and total heating for equivalence, and the other uses relatively low constant heat flux or stepped varying heat flux combined with total heating for equivalence. When designing simulated heating test conditions, attention is paid to matching other relevant parameters such as total enthalpy, pressure, and shear force, but generally, the values ​​or ranges of these parameters are not subject to overly strict restrictions. Furthermore, targeted experimental studies are conducted on specific parameter ranges, such as high enthalpy, high shear, and high pressure, to confirm the safety of heat protection structures or materials under extreme aerodynamic heating environments. While these conventional design methods largely address the specific engineering needs of aircraft heat protection design and optimization, they exhibit a degree of arbitrariness in stepped heating state design, and in certain states, may result in significant over- or under-testing, hindering the scientific design and efficient optimization of aircraft heat protection systems to some extent.

[0004] To address the issues of insufficient accuracy in assessment and lack of theoretical calculation basis for state determination caused by experience-based design, a step heating state design method that can achieve precise matching of multiple physical quantities is urgently needed. Summary of the Invention

[0005] This invention provides a step heating design method, equipment, and medium for simulating ballistic ablation response. Based on the principle of equivalent total heating, it deeply integrates a high-precision simulation model of ablation thermal response verified through experiments. Through an iterative algorithm, the total enthalpy of the incoming flow is optimized using ablation deviation as the convergence condition, and the incoming heat flux is optimized using temperature response deviation at key locations as the convergence condition. This ensures that ground tests can reproduce the real flight conditions in both macroscopic ablation and microscopic temperature fields. It solves the problem of arbitrary state design in traditional methods and achieves a perfect match between total heating, ablation, and temperature response at key points.

[0006] This invention provides a step heating design method for simulating ballistic ablation response, characterized by comprising: The target response parameters under the flight ballistic environment are obtained. The target response parameters include at least the target ablation retreat amount and the highest temperature at the target critical position. Based on the preset benchmark step parameters, the initial simulated ablation retreat amount and simulated highest temperature at the critical position are prepared for iterative calculation by determining the heating time, adjusting the test state and performing ablation thermal response calculation. Based on the target response parameters, the step heating state parameters of the ground simulation test are determined through iterative calculation, which includes: First iteration step: With the target ablation retreat as the objective, iteratively update the total enthalpy coefficient used to determine the total enthalpy of the ground flow; Second iteration step: Based on satisfying the target ablation retreat amount, and with the target of matching the highest temperature at the key location of the target, iteratively update the heat flux density coefficient used to determine the ground heat flux density; Output the step heating state parameters of the ground simulation test determined by the final iteration.

[0007] According to an embodiment of the present invention, an electronic device is provided, comprising: Processor; and, A memory is configured to store computer-executable instructions, which, when executed, cause the processor to perform the steps of the aforementioned step heating design method for simulating ballistic ablation response.

[0008] This invention provides a storage medium for storing computer-executable instructions, which, when executed, implement the steps of the aforementioned step heating design method for simulating ballistic ablation response.

[0009] This invention employs iterative methods to obtain the optimal total enthalpy of the incoming flow by limiting ablation deviation and to obtain the optimal heat flux of the incoming flow by limiting temperature deviation at key design points. It combines the inputs of the reference step heating duration, heat flux, and total enthalpy with the heat flux coefficient, heating duration coefficient, and total enthalpy coefficient to meet the design requirements for heating states with any number of steps. This achieves a complete match between the total heating amount, ablation amount, and maximum temperature response at key locations under step heating states and the response parameters under flight trajectory states. This addresses the potential problems of arbitrariness, over-testing, or under-testing in step heating state design using conventional design methods. This invention features significant multi-parameter equivalent simulation effects and convenient technical implementation, providing a specific technical approach for ground test simulation or assessment state design of aircraft thermal protection systems or thermal protection materials, and possesses significant engineering value. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in one or more embodiments of this specification or in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a flowchart of a step heating design method for simulating ballistic ablation response according to an embodiment of the present invention; Figure 2 This is a schematic diagram illustrating a specific implementation of the step heating design method for simulating ballistic ablation response according to an embodiment of the present invention. Figure 3 This is a schematic diagram of parameters under a virtual ballistic heating environment, where 3(a) represents the heat flux density value under the virtual ballistic heating environment. Figure 3 (b) represents the total enthalpy under the virtual ballistic heating environment. Figure 3 (c) represents the pressure value under the virtual ballistic heating environment. Figure 3 (d) represents the total heating parameter value under the virtual ballistic heating environment; Figure 4 This is a schematic diagram comparing the ablation and carbonization amount and key point temperature of a typical single-step ground test under equivalent simulation design state heating and ballistic state heating, according to an embodiment of the present invention. Figure 4 (a) is a schematic diagram comparing the amount of ablation and carbonization. Figure 4 (b) is a comparative diagram of the temperatures at key points; Figure 5 This is a schematic diagram comparing the ablation and carbonization amount and key point temperature of a typical multi-step ground test equivalent simulation design state heating and ballistic state heating in an embodiment of the present invention. Figure 5 (a) is a schematic diagram comparing the amount of ablation and carbonization. Figure 5 (b) is a schematic diagram comparing the temperatures at key points. Detailed Implementation

[0012] To enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the technical solutions in one or more embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this specification, and not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this document.

[0013] Method Implementation Examples According to embodiments of the present invention, a step heating design method for simulating ballistic ablation response is provided. Figure 1 This is a flowchart of the step heating design method for simulating ballistic ablation response according to an embodiment of the present invention. Figure 1 As shown, the step heating design method for simulating ballistic ablation response in this embodiment of the invention specifically includes: S1. Obtain target response parameters under the flight ballistic environment. These parameters include at least the target ablation retreat and the highest temperature at the target's critical location. Based on preset benchmark step parameters, determine the heating duration, adjust the test state, and perform ablation thermal response calculations to prepare initial simulated ablation retreat and simulated highest temperature at the critical location for iterative calculations. Figure 2 The specific operation is as follows: S11. Using the ablation thermal response calculation method for alternative ablation heat protection materials for aircraft, perform ablation thermal response calculations for heat protection materials or structures under a given flight ballistic aerodynamic heating environment to obtain the surface ablation retreat amount. Response of highest temperature at critical locations on or inside the material surface Simultaneously, based on the given heat flux density value of the aerodynamic heating environment of the flight trajectory... The total amount of heat that the material surface needs to withstand is calculated by integration. .

[0014] ; in, This is the derivative of the flight trajectory time.

[0015] The reference heat flux density, reference total enthalpy, and reference duration are given according to the design requirements, as shown in Table 1.

[0016] Table 1. Reference heat flux density and reference total enthalpy step

[0017] Where j=1,2,3,...N, is the sequence number of the step start-up sequence.

[0018] Table 2 below shows a typical reference heat flux density and reference total enthalpy step, with 6 steps. Table 2 Typical reference heat flux density and reference total enthalpy step

[0019] S12. Determine the heating time, the specific steps are as follows: Given heat flux density coefficient Convert all calculations in the current calculation step. N The heat flux density of each step : ; The simulated heating duration coefficient is determined based on the total heating amount. ,coefficient The formula for calculation is: ; in, , where is the number of iterations for calculating the heat flux density coefficient.

[0020] Based on the simulated heating time coefficient Convert all calculations in the current calculation step. N Duration of each step : ; At the same time, an initial value for the total enthalpy coefficient is given. .

[0021] S13. Conduct test state debugging, specifically including: Given total enthalpy coefficient Convert all calculations in the current calculation step. N Total enthalpy of the flow at each step .

[0022] in, , representing the number of iterations for calculating the total enthalpy coefficient. The specific conversion formula is as follows: , ; Ground simulation tests were conducted using the same heat-resistant materials or structures as the aircraft to determine the required heat flux density. Based on the capabilities of ground equipment and through empirical data or on-site testing, the required heat flux density was determined. Total enthalpy of incoming flow Incoming flow pressure or shear force parameters .

[0023] S14. Perform ablation thermal response calculations, specifically including: Using the same heat-resistant materials or structures as the aircraft, ablation thermal response calculations were conducted on the heat-resistant materials or structures under a given ground test step heating state. The number of steps was... The thermal environment parameters for each step are as follows: step duration Heat flux density is Total enthalpy of incoming flow Surface pressure of materials or structures or shear force .

[0024] Calculate the amount of ablation and retreat of the heat-resistant material or structural surface under the heated state of this step. Response of highest temperature at critical locations on or inside the material surface .

[0025] Figure 3 This represents a typical virtual ballistic aerodynamic heating environment, where 3(a) is the heat flux density value under the virtual ballistic heating environment. Figure 3 (b) represents the total enthalpy under the virtual ballistic heating environment. Figure 3 (c) represents the pressure value under the virtual ballistic heating environment. Figure 3 (d) represents the total heating parameter value under the virtual ballistic heating environment.

[0026] S2. Based on the target response parameters, determine the step heating state parameters of the ground simulation test through iterative calculation, wherein the iterative calculation includes: First iteration step: Taking the target ablation retreat as the objective, iteratively update the total enthalpy coefficient used to determine the total enthalpy of the ground inflow. The first iteration step includes: S211. Based on the initial or updated total enthalpy coefficient, determine the total enthalpy of the surface inflow and the corresponding inflow pressure or shear force parameters; S212. Based on the current heat flux density, duration, total enthalpy of incoming flow, and incoming flow pressure or shear force parameters, perform ablation thermal response calculations to obtain the ablation retreat under ground simulation conditions. S213. Compare the calculated ablation retreat amount with the target ablation retreat amount. If the deviation exceeds the permissible range, update the total enthalpy coefficient and return to execute S211.

[0027] The specific calculation steps for S211 and S212 can be found in step S1.

[0028] More specifically, the amount of surface ablation retreat under heated conditions in ground tests. and the amount of surface ablation retreat under the aerodynamic heating environment of flight ballistics Compare the two and calculate the difference. : ; Given the allowable deviation of ablation amount ,like If so, proceed to the second iteration step; if ,Pick Update using an optimized algorithm The value is repeated in S211.

[0029] in, The value is determined by the designer, and is generally 0.01 mm. Commonly used optimization algorithms include: bisection method, Newton's method, conjugate gradient method, etc.

[0030] A typical iterative process is shown in Table 3: Table 3. Record of typical iterative process in equivalent simulation of multi-step ground test

[0031] The second iteration step: Based on satisfying the target ablation retreat amount, and with the target being the highest temperature at the key location, iteratively update the heat flux density coefficient used to determine the ground heat flux density. The second iteration step includes: S221. Calculate the heat flux density and duration of each step based on the initial or updated heat flux density coefficient and heating duration coefficient. S222. Execute the first iteration step to obtain the current parameter set that meets the target ablation retreat requirement; S223. Based on the parameter set obtained in S222, thermal response calculations were performed to obtain the highest temperature at key locations under ground simulation conditions. S224. Compare the calculated highest temperature at the critical location with the highest temperature at the target critical location. If the deviation exceeds the permissible range, update the heat flux density coefficient and return to execute S221.

[0032] More specifically, the response of the highest temperature at key locations on the surface or inside of the material under heated conditions during ground testing. The highest temperature response of material surface or critical internal locations under aerodynamic heating environment of flight trajectory Compare and calculate the difference. : ; Given temperature deviation allowance ,like Proceed to step S3; if ,Pick Update using an optimized algorithm The value is returned, and S221 is executed.

[0033] in, The value is determined by the designer, and is generally 0.1K. Commonly used optimization algorithms include: bisection method, Newton's method, conjugate gradient method, etc. A typical iterative process is shown in Table 4.

[0034] Table 4. Record of typical iterative process in equivalent simulation of multi-step ground test

[0035] S3. Output the step heating state parameters of the ground simulation test determined by the final iteration.

[0036] Furthermore, the step heating state parameters include at least one of the following: heat flux density, duration, total enthalpy of incoming flow, incoming flow pressure, and shear force of each step.

[0037] Based on the heat flux density coefficient under the current calculation conditions Simulated heating time coefficient Total enthalpy coefficient Calculate the duration of all N steps. Heat flux density is Total enthalpy of incoming flow Surface pressure of materials or structures or shear force This refers to the equivalent simulation of the heating flow state parameters for the multi-step ground test to meet the design requirements. A typical output result is shown in Table 5.

[0038] Table 5. Equivalent simulation design results of typical multi-step ground tests

[0039] Using this step-based flow state parameter for ground simulation experiments, the total heating, ablation, and peak temperature response at key locations can be simulated to be identical to those in flight experiments. Typical simulation results are as follows: Figure 4 and Figure 5 As shown, where, Figure 4 (a) is a schematic diagram comparing the amount of ablation and carbonization. Figure 4 (b) is a comparative diagram of the temperatures at key points; Figure 5 (a) is a schematic diagram comparing the amount of ablation and carbonization. Figure 5 (b) is a schematic diagram comparing the temperatures at key points.

[0040] This invention is applicable, but not limited to, the equivalent simulation problem of aerodynamic heating steps in the flight process of various types of heat-resistant materials or structures in the Earth's atmosphere and planetary atmospheres. Furthermore, for heat-resistant materials where mechanical erosion is the main mass loss mechanism or for ablation problems where pressure and shear force are the main ablation mechanisms, simply replacing "total enthalpy" with "pressure and shear force" in the above variables, and simultaneously replacing the process of "obtaining pressure and shear force through experimental debugging" with "obtaining the total enthalpy of the incoming flow through experimental debugging," can achieve the design of multi-step equivalent simulation states for such problems.

[0041] Compared with existing technologies, the advantages of this invention are as follows: Compared with conventional step design methods that only use total heating amount as a constraint, this invention uses ablation deviation constraint iteration to obtain the optimal incoming total enthalpy, and uses critical design point temperature deviation constraint iteration to obtain the optimal incoming heat flux. It uses the benchmark step heating time, heat flux, and total enthalpy input combined with heat flux coefficient, heating time coefficient, and total enthalpy coefficient to meet the design requirements of heating states with any number of steps, thereby achieving a complete match between the total heating amount, ablation amount, and maximum temperature response at critical locations under step heating states and the response parameters under flight trajectory states. This can solve the potential problems of arbitrariness, over-testing, or under-testing in step heating state design of conventional design methods. This invention has the characteristics of significant multi-parameter equivalent simulation effect and convenient technical implementation, and can provide a specific technical approach for the design of ground test simulation or evaluation states for aircraft thermal protection systems or thermal protection materials, possessing significant engineering value.

[0042] Device Example 1 According to an embodiment of the present invention, an electronic device is provided, comprising: Processor; and, A memory is configured to store computer-executable instructions, which, when executed, cause the processor to perform the steps of the step heating design method for simulating ballistic ablation response described above.

[0043] Device Example 2 According to an embodiment of the present invention, a storage medium is provided for storing computer-executable instructions, which, when executed, implement the steps of the above-described step heating design method for simulating ballistic ablation response.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A step heating design method for simulating ballistic ablation response, characterized in that... include: Acquire target response parameters under a flight ballistic environment, wherein the target response parameters include at least the target ablation retreat and the highest temperature at the target's critical location; Based on the preset benchmark step parameters, the initial simulated ablation retreat and the highest temperature at the simulated key location are prepared for iterative calculation by determining the heating time, adjusting the test state, and performing ablation thermal response calculation. Based on the target response parameters, the step heating state parameters of the ground simulation test are determined through iterative calculation, which includes: First iteration step: With the target ablation retreat as the objective, iteratively update the total enthalpy coefficient used to determine the total enthalpy of the ground flow; Second iteration step: Based on satisfying the target ablation retreat amount, and with the target of matching the highest temperature at the key location of the target, iteratively update the heat flux density coefficient used to determine the ground heat flux density; Output the step heating state parameters of the ground simulation test determined by the final iteration.

2. The method according to claim 1, characterized in that, The step heating state parameters include at least one of the following: heat flux density, duration, total enthalpy of incoming flow, incoming flow pressure, and shear force of each step.

3. The method according to claim 1, characterized in that, The first iterative step specifically includes: S211. Based on the initial or updated total enthalpy coefficient, determine the total enthalpy of the surface inflow and the corresponding inflow pressure or shear force parameters; S212. Based on the current heat flux density, duration, total enthalpy of incoming flow, and incoming flow pressure or shear force parameters, perform ablation thermal response calculations to obtain the ablation retreat under ground simulation conditions. S213. Compare the calculated ablation retreat amount with the target ablation retreat amount. If the deviation exceeds the permissible range, update the total enthalpy coefficient and return to execute S211.

4. The method according to claim 3, characterized in that, The second iteration step specifically includes: S221. Calculate the heat flux density and duration of each step based on the initial or updated heat flux density coefficient and heating duration coefficient. S222. Execute the first iteration step to obtain the current parameter set that meets the target ablation retreat requirement; S223. Based on the parameter set obtained in S222, thermal response calculations were performed to obtain the highest temperature at key locations under ground simulation conditions. S224. Compare the calculated highest temperature at the critical location with the highest temperature at the target critical location. If the deviation exceeds the permissible range, update the heat flux density coefficient and return to execute S221.

5. The method according to claim 4, characterized in that, The heating duration coefficient is determined based on the total heating amount of the material surface under the flight ballistic environment.

6. The method according to claim 4, characterized in that, In S21, the heat flux density of each step is calculated. With duration This can be achieved through the following formula: , ； , ； in, For a given heat flux density coefficient, To simulate the heating duration coefficient, j is the sequence number of the step start-up timing. , where is the number of iterations for calculating the heat flux density coefficient.

7. The method according to claim 3, characterized in that, In step S11, the determination of the total enthalpy of the surface inflow is achieved using the following formula: , ； Given the total enthalpy coefficient, This represents the total enthalpy of each step.

8. The method according to claim 7, characterized in that, The method for determining the corresponding incoming flow pressure or shear force parameter in S11 is as follows: Using the total enthalpy of the incoming flow from the ground and the current heat flux density as inputs, and based on the aerodynamic-thermal correlation preset by the ground test equipment, the incoming flow pressure or shear force parameters corresponding to the combination of heat flux density and total enthalpy are solved.

9. An electronic device, comprising: processor; as well as, A memory configured to store computer-executable instructions, which, when executed, cause the processor to perform the steps of the step heating design method for simulating ballistic ablation response as described in any one of claims 1-8.

10. A storage medium for storing computer-executable instructions, which, when executed, implement the steps of the step heating design method for simulating ballistic ablation response as described in any one of claims 1-8.

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