A method for calculating ablation of heterogeneous nose tip with anti-ablation components
By using a heterogeneous end-ablation calculation method, a dimensionless mass ablation rate database was established and the ablation temperature field calculation was decoupled, which solved the accuracy and efficiency problems of ablation rate calculation for high-speed aircraft and reduced design costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING LINJIN SPACE AIRCRAFT SYST ENG INST
- Filing Date
- 2026-06-10
- Publication Date
- 2026-07-10
AI Technical Summary
Existing technologies for calculating the ablation rate of high-speed aircraft face challenges such as low accuracy in temperature field calculations due to complex topological shapes, low accuracy in ablation rate calculations due to the presence of oxide films, low computational efficiency due to coupled ablation temperature field calculation models, and high costs associated with thermal protection design.
A heterogeneous end-ablation calculation method is adopted. A dimensionless mass ablation rate database is established through suborthogonal experiments. The least squares method is used to correct the coefficient matrix. Combined with the surface energy balance equation and the heat conduction equation, the ablation temperature field calculation process is decoupled, reducing the number of wind tunnel tests.
It significantly improves computational efficiency, reduces thermal protection design costs, enhances computational accuracy, avoids the practice of conducting numerous wind tunnel tests in traditional design processes, and conforms to real physical processes.
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Figure CN122365728A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of heterogeneous heat-resistant components, and particularly relates to a method for calculating the ablation of heterogeneous end caps containing anti-ablation components. Background Technology
[0002] High-speed aircraft operate for extended periods under aerodynamic heating conditions characterized by low pressure, high enthalpy, and medium to low heat flux. To meet range design requirements, they typically need to maintain extremely high lift-to-drag ratio aerodynamic characteristics. For high-heat flux heat shield components such as the nose and wing leading edge, their ablation rate must be strictly controlled. Traditional heat shield designs mainly face the following problems: (1) Complex topological shape leads to low accuracy of temperature field calculation. Traditional spacecraft, represented by the return capsule, mostly adopt axisymmetric rotating body shape. This shape is simple, the aerodynamic design is mature, and the performance is good. It is usually regarded as a one-dimensional or axisymmetric heat transfer model to calculate and analyze the ablation and temperature evolution process of the spacecraft. However, high-speed spacecraft usually adopt complex topological shapes such as surface symmetry or waverider. Their aerodynamic heating and heat transfer usually have two types of characteristics: 1) The surface thermal environment distribution characteristics are complex due to the large number of control components such as wings, rudders, ventral fins, and side plates. Shock wave-shock wave and shock wave-boundary layer interference are serious; 2) The three-dimensional heat transfer effect is prominent. If the calculation and analysis are still performed using a one-dimensional ablation temperature field model, the results often have a large deviation from the ground and flight test results.
[0003] (2) The presence of oxide film leads to low accuracy in ablation rate calculation. To achieve the goal of low ablation in heat protection, the design generally adopts matrix-modified low-ablation heat protection materials. The process characteristics of such materials are: adding refractory metal anti-ablation components to carbon-based or ceramic-based heat protection materials, forming a loose oxide film on the surface, which slows down the diffusion rate of oxygen to the substrate surface, thereby significantly reducing the ablation rate of the material, i.e., low-ablation heat protection materials. To achieve this low ablation goal, the survival of the loose oxide film is crucial. However, under actual flight conditions, the scouring and erosion effect of the external high-speed flow field on the oxide film is significant. For example, under the high shear force scouring conditions in the downpressure section, after the oxide film is completely washed away, the material not only fails to achieve the design goal of low ablation, but the total ablation amount is even significantly higher than that of heat protection materials without added antioxidant components. Therefore, it is necessary to establish a material ablation calculation model that considers the survival and shedding of oxide film in order to improve the accuracy of material ablation calculation. However, it is extremely difficult to obtain the mathematical model and material parameters of such loose oxide film in the process of high-speed flow field scouring. It is usually impossible to obtain a relatively accurate calculation method through mathematical modeling and simulation analysis.
[0004] (3) The coupled calculation model and method of ablation temperature field leads to low computational efficiency. The thermochemical ablation model of materials is generally a multivariate high-order equation system. For simple one-dimensional heat transfer / axisymmetric heat transfer models, the one-dimensional heat transfer calculation-thermochemical ablation coupled solution corresponding to each unit node is acceptable. However, for the aerodynamic shape of high-speed aircraft with complex topology, the amount of surface mesh node data is many orders of magnitude greater than that of one-dimensional / axisymmetric models, which leads to a significant reduction in overall computational efficiency and often results in the calculation results not converging.
[0005] (4) High cost of heat protection design. For heat protection materials containing ablation-resistant components, the prediction of oxide film formation and loss in high-temperature and oxygen-rich environments is still a global problem. For different flight environments, in addition to numerical simulation, it is often necessary to arrange corresponding ground wind tunnel tests and combine the test results to correct the numerical simulation results. Summary of the Invention
[0006] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a heterogeneous end ablation calculation method containing anti-ablation components. This method can decouple the complex ablation temperature field coupling calculation process, and on the basis of greatly improving the calculation efficiency, it avoids the practice of conducting a large number of wind tunnel ablation tests for different flight environments in the traditional design process, thereby achieving the effect of greatly reducing the cost of heat protection design.
[0007] The objective of this invention is achieved through the following technical solution: a method for calculating the ablation of a heterogeneous end cap containing an ablation-resistant component, comprising: Step S1: using heat flux, pressure, and recovery enthalpy as state adjustment parameters for an arc wind tunnel test, and conducting... The orthogonal experiment yielded the following results: A database of mass ablation rates for individual samples; among which... For positive integers; Step S2: Establish an ablation calculation model; wherein, the ablation calculation model includes the element mass conservation equation, the gas partial pressure law equation, and the chemical reaction equation; Step S3: Substitute the preset temperature and pressure combination sequence into the ablation calculation model to obtain a discrete database of dimensionless mass ablation rate; Step S4: Based on the data containing... Step S5: Obtain the discrete database of dimensionless mass ablation rate from the mass ablation rate database of each sample and the dimensionless mass ablation rate equation; Step S6: Use the least squares method to obtain the correction coefficient matrix of the discrete database of dimensionless mass ablation rate, and obtain the corrected discrete database based on the correction coefficient matrix and the discrete database of dimensionless mass ablation rate; Surface energy balance equation at time; Step S7: Substituting the surface energy balance equation at time 1 into the heat conduction equation, we obtain... Temperature field at any time, according to Temperature field at any time, preset The pressure distribution in the aerothermal environment parameters at time t is obtained by interpolation with the corrected discrete database. The dimensionless mass ablation rate of each surface node of the spacecraft at any given time, based on The equations for the dimensionless mass ablation rate and dimensionless mass ablation velocity of each surface node of the spacecraft are obtained. Mass ablation rate of each surface node at any given time.
[0008] The above-mentioned method for calculating the ablation of heterogeneous ends containing ablation-resistant components also includes: Substitute the mass ablation rate of each surface node at time step The surface energy balance equation at time t is obtained The surface energy balance equation at each moment is repeated, and step S7 is repeated until the flight ends.
[0009] In the above calculation method for isomeric end ablation containing ablation-resistant components, the element mass conservation equation is obtained through the following formula: ; in, , , The first The mass fraction of each chemical component at the outer edge of the boundary layer, on the material surface, and in the pyrolysis gas; For the first Molar mass of each chemical component; For the first The chemical component in the first The number of atoms in each gaseous component; To control the first Partial pressure of each gas component; , These are the dimensionless mass ablation rate and the dimensionless pyrolysis gas mass flow rate, respectively. The average molar mass of the mixed gas at the material surface control volume; To control the total pressure of the gas mixture, For gas component index, This is an index for chemical components.
[0010] In the above calculation method for ablation of heterogeneous ends containing ablation-resistant components, the gas partial pressure law equation is obtained through the following formula: ; in, To control the first Partial pressure of each gas component; To control the total pressure of the gas mixture, This is an index for gas components.
[0011] In the above calculation method for isomeric end-face ablation containing anti-ablation components, the chemical reaction equation is obtained through the following formula: ; in, For temperature The equilibrium constant of this chemical reaction. The order of a chemical reaction. For gas component index, For temperature, This is the multiplication symbol.
[0012] In the above method for calculating the ablation rate of heterogeneous ends containing ablation-resistant components, the dimensionless mass ablation rate equation is obtained through the following formula: ; in, The dimensionless mass ablation rate, The ablation rate is the percentage of material quality. To restore enthalpy at the end of the stationary point, For material density, The ejection factor, It is a hot flow through a cold wall.
[0013] In the above calculation method for ablation of heterogeneous ends containing ablation-resistant components, The surface energy balance equation at time t is obtained through the following formula: ; in, For the net heat flow into the material, For cold wall heat flow, For the surface emissivity of the material, It is the Stefan-Boltzmann constant; For mass ablation rate, For wall enthalpy, To restore enthalpy, The heat of ablation reaction, This refers to the wall temperature.
[0014] In the above calculation method for ablation of isomeric ends containing ablation-resistant components, the heat of ablation reaction is... The following conditions must be met: ; in, For the first The mass concentration of each chemical component at the wall surface For the first The heat of reaction of each chemical component The total number of chemical components. This is an index for chemical components.
[0015] A heterogeneous end-face ablation calculation system containing an ablation-resistant component includes: a first module for conducting state-tuning tests using heat flux, pressure, and recovery enthalpy as conditions in an electric arc wind tunnel. The orthogonal experiment yielded the following results: A database of mass ablation rates for individual samples; among which... The first module is for positive integers; the second module is for establishing an ablation calculation model, which includes the elemental mass conservation equation, the gas partial pressure law equation, and the chemical reaction equation; the third module is for substituting a preset temperature and pressure combination sequence into the ablation calculation model to obtain a discrete database of dimensionless mass ablation rate; the fourth module is for... The fifth module is used to obtain a discrete database of dimensionless mass ablation rate from the mass ablation rate database of individual samples and the dimensionless mass ablation rate equation; the sixth module is used to obtain a correction coefficient matrix for the discrete database of dimensionless mass ablation rate using the least squares method; the sixth module is used to establish... The surface energy balance equation at time t; Module 7, used to... Substituting the surface energy balance equation at time 1 into the heat conduction equation, we obtain... Temperature field at any time, according to Temperature field at any time, preset The pressure distribution in the aerothermal environment parameters at time t is obtained by interpolation with the corrected discrete database. The dimensionless mass ablation rate of each surface node of the spacecraft at any given time, based on The equations for the dimensionless mass ablation rate and dimensionless mass ablation velocity of each surface node of the spacecraft are obtained. Mass ablation rate of each surface node at any given time.
[0016] An electronic device includes: a memory for storing computer-readable instructions; and a processor for executing the computer-readable instructions to perform a heterogeneous end-face ablation calculation method containing ablation-resistant components.
[0017] Compared with the prior art, the present invention has the following advantages: (1) This invention quantifies the correlation between dimensionless mass ablation rate and temperature and pressure, and establishes a discrete point database of dimensionless mass ablation rate as a function of temperature and pressure. In the ablation-temperature field coupled solution process, the dimensionless mass ablation rate value is obtained by interpolation in the database based on temperature and pressure. This makes the calculation part of the multivariate high-order equations of the thermochemical ablation equation set independent of the temperature field solution process, which can greatly improve the calculation efficiency. (2) By designing orthogonal wind tunnel test sample data, the present invention corrects the temperature and pressure database of dimensionless mass ablation rate, and uses the oxide film peeling data of real test results to correct the database of dimensionless mass ablation rate values. This can avoid mathematical modeling of the ablation process under the conditions of oxide film formation and high-speed flow field scouring, and is more in line with the real physical process. (3) After the dimensionless mass ablation rate is quantitatively correlated with temperature and pressure, the dimensionless mass ablation rate value established in this invention is only a dependent variable of temperature and pressure, and only participates in the calculation of surface energy balance and final linear ablation rate. On the basis of improving calculation efficiency, the risk of divergence in the calculation process is reduced. At the same time, the three-dimensional temperature field calculation result is used as the calculation parameter for interpolation to obtain the dimensionless mass ablation rate value, and the influence of three-dimensional heat transfer effect on the ablation calculation result is considered, and the calculation accuracy is further improved. (4) By establishing a general ablation database in advance, the present invention decouples the complex ablation temperature field coupling calculation process, which greatly improves the calculation efficiency and avoids the practice of conducting a large number of wind tunnel ablation tests for different flight environments in the traditional design process, thus greatly reducing the design cost. Attached Figure Description
[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a schematic diagram of the surface energy balance equation provided in an embodiment of the present invention; Figure 2 This is a flowchart of a heterogeneous end-point ablation calculation method containing anti-ablation components provided in an embodiment of the present invention. Detailed Implementation
[0019] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0020] Figure 1 This is a schematic diagram of the energy balance equation provided in an embodiment of the present invention; Figure 2 This is a flowchart of a heterogeneous end-point ablation calculation method containing anti-ablation components provided in an embodiment of the present invention.
[0021] like Figure 2 As shown, this embodiment provides a method for calculating the ablation of heterogeneous ends containing ablation-resistant components. The method includes: Step S1: Using heat flux, pressure, and recovery enthalpy as the state-based debugging parameters for the electric arc wind tunnel test, conduct... The orthogonal experiment yielded the following results: A database of mass ablation rates for individual samples; among which... It is a positive integer; Step S2: Establish an ablation calculation model; wherein, the ablation calculation model includes the element mass conservation equation, the gas partial pressure law equation, and the chemical reaction equation; Step S3: Substitute the preset temperature and pressure combination sequence into the ablation calculation model to obtain a discrete database of dimensionless mass ablation rate; Step S4: Based on containing A discrete database of experiments using a sample mass ablation rate database and a dimensionless mass ablation rate equation to obtain the dimensionless mass ablation rate. Step S5: Use the least squares method to obtain the discrete database of the dimensionless mass ablation rate test and the correction coefficient matrix of the discrete database of the dimensionless mass ablation rate. Based on the correction coefficient matrix and the discrete database of the dimensionless mass ablation rate, obtain the corrected discrete database. Step S6: Establish The surface energy balance equation at time t; Step S7: [The text appears to be incomplete and contains several grammatical errors. A more accurate translation would require the full context.] Substituting the surface energy balance equation at time 1 into the heat conduction equation, we obtain... Temperature field at any time, according to Temperature field at any time, preset The pressure distribution in the aerothermal environment parameters at time t is obtained by interpolation with the corrected discrete database. The dimensionless mass ablation rate of each surface node of the spacecraft at any given time, based on The equations for the dimensionless mass ablation rate and dimensionless mass ablation velocity of each surface node of the spacecraft are obtained. Mass ablation rate of each surface node at any given time.
[0022] The method also includes: Substitute the mass ablation rate of each surface node at time step The surface energy balance equation at time t is obtained The surface energy balance equation at each moment is repeated, and step S7 is repeated until the flight ends.
[0023] The equation for the conservation of mass of elements is obtained through the following formula: ; in, , , The first The mass fraction of each chemical component at the outer edge of the boundary layer, on the material surface, and in the pyrolysis gas; For the first Molar mass of each chemical component; For the first The chemical component in the first The number of atoms in each gaseous component; To control the first Partial pressure of each gas component; , These are the dimensionless mass ablation rate and the dimensionless pyrolysis gas mass flow rate, respectively. The average molar mass of the mixed gas at the material surface control volume; To control the total pressure of the gas mixture, For gas component index, This is an index of chemical components. Chemical elements are those that undergo chemical reactions on the material surface, including the chemical composition of the substrate and the flow field.
[0024] The law of partial pressures of gases is obtained through the following formula: ; in, To control the first Partial pressure of each gas component; To control the total pressure of the gas mixture, This is an index for gas components.
[0025] The chemical reaction equation is obtained through the following formula: ; in, For temperature The equilibrium constant of this chemical reaction. The order of a chemical reaction. For gas component index, For temperature, This is the multiplication symbol.
[0026] The dimensionless mass ablation rate equation is obtained through the following formula: ; in, The dimensionless mass ablation rate, The ablation rate is the percentage of material quality. To restore enthalpy at the end of the stationary point, For material density, The ejection factor, It is a hot flow through a cold wall.
[0027] The surface energy balance equation at time t is obtained through the following formula: ; in, For the net heat flow into the material, For cold wall heat flow, For the surface emissivity of the material, It is the Stefan-Boltzmann constant; For mass ablation rate, For wall enthalpy, To restore enthalpy, The heat of ablation reaction, This refers to the wall temperature.
[0028] ablation reaction heat The following conditions must be met: ; in, For the first The mass concentration of each chemical component at the wall surface For the first The heat of reaction of each chemical component The total number of chemical components. This is an index for chemical components.
[0029] In the thermal protection design of high-speed spacecraft, solving the thermochemical ablation problem typically requires solving a system of multivariate high-order thermochemical reaction equations simultaneously. For axisymmetric spinning vehicles with simple aerodynamic shapes, this can be simplified to a one-dimensional or axisymmetric problem with manageable computational cost. However, for high-speed heterogeneous vehicles with complex shapes, a three-dimensional heat transfer and ablation problem must be addressed. The massive three-dimensional computational mesh has a large number of surface nodes, and iteratively solving the coupled equations using implicit schemes requires significant computational resources. Furthermore, the high-order equations are particularly prone to divergence, frequently posing a risk of computational non-convergence.
[0030] This embodiment provides an ablation calculation method for heterogeneous heat-resistant components containing ablation-resistant elements. By conducting orthogonal combined wind tunnel ablation tests beforehand, a universal ablation database is established in one go. This significantly improves computational efficiency and solves the problem of computational non-convergence. Furthermore, this method eliminates the need for ground tests to verify and correct the calculation results for every different flight environment. The specific steps of this method are as follows: Step 1): Using heat flow ,pressure Enthalpy restoration Conditioning parameters for electric arc wind tunnel testing , carry out The orthogonal experiment yielded the following results: The database of mass ablation rates for samples, the first The mass ablation rate of this experiment is recorded as: ;in, Number the test samples.
[0031] Step 2): Establish an ablation calculation model based on the material's processing characteristics, chemical composition, refractory metal content, and other process parameters. The specific method is as follows: The ablation calculation model includes: the element mass conservation equation (1), the gas partial pressure law equation (2), and the chemical reaction equation (3).
[0032] a) Using the thermochemical ablation theory, it can be deduced that the ablated surface of the material must satisfy the element mass conservation equation: (1) in, , , The first The mass fraction of each chemical component at the outer edge of the boundary layer, on the material surface, and in the pyrolysis gas; For the first Molar mass of each chemical component; For the first The chemical component in the first The number of atoms in each gaseous component; To control the first Partial pressure of each gas component; , These are the dimensionless mass ablation rate and the dimensionless pyrolysis gas mass flow rate, respectively. The average molar mass of the mixed gas at the material surface control volume; To control the total pressure of the gas mixture, For gas component index, This is an index of chemical components. Chemical elements are those that undergo chemical reactions on the material surface, including the chemical composition of the substrate and the flow field.
[0033] b) The ablation surface of the material must satisfy the gas partial pressure law equation: (2) in, To control the first Partial pressure of each gas component; To control the total pressure of the gas mixture, This is an index for gas components.
[0034] c) The ablation surface of the material must satisfy the chemical equilibrium equation: (3) in, For temperature The equilibrium constant of this chemical reaction. The order of a chemical reaction. For gas component index, For temperature, This is the multiplication symbol.
[0035] Step 3): In the system of equations consisting of equations (1) to (3), when the temperature... ,pressure Once determined, the unknowns can be calculated. (Dimensionless mass ablation rate), therefore, respectively, by temperature ,pressure Using the coordinate axes, for different temperatures ,pressure combination( , For serial number, (where the total number of serial numbers is 1), it can be calculated that Discrete database .
[0036] Step 4): For the product obtained in Step 1) containing Measured mass ablation rate of a sample in an electric arc wind tunnel test Its relationship with dimensionless mass ablation rate The relationship between them satisfies equation (4): (4) in, The dimensionless mass ablation rate, The ablation rate is the percentage of material quality. To restore enthalpy at the end of the stationary point, For material density, The ejection factor, It is a hot flow through a cold wall.
[0037] Based on equation (4) and experimental state parameters ( The experimental state can be calculated. The corresponding discrete database of experiments .
[0038] Due to step 3) ( , For serial number, (The total number of serial numbers) is data calculated using temperature and pressure as input. Therefore, when selecting... When using coordinate points, it is entirely possible to achieve this. and Using the same coordinate.
[0039] Step 5): Using the least squares method, obtain the result from step 4). For step 3) Correction coefficient matrix This leads to the corrected discrete database. ,satisfy: = .
[0040] Step 6): Establish The surface energy balance equation at time t.
[0041] The aerodynamic thermal environment input under flight conditions is defined by state parameters such as time, heat flux, pressure, and enthalpy. For example... Figure 1 As shown, for Timing: Based on the shape of the heat-resistant components, the thermophysical properties of the heat-resistant materials, and... The ablation amount calculated at each moment can be used to establish the surface energy balance equation: (5) in, For the net heat flow into the material, For hot wall heat flow, For cold wall heat flow, For radiative heat flow, This is the heat of chemical reaction during the ablation process; For the surface emissivity of the material, It is the Stefan-Boltzmann constant; For mass ablation rate, For wall enthalpy, To restore enthalpy, The heat of ablation reaction, This refers to the wall temperature.
[0042] ablation reaction heat The following conditions must be met: ; in, For the first A chemical component on the wall The mass concentration at that location, For the first The heat of reaction of each chemical component The total number of chemical components. This is an index for chemical components.
[0043] Step 7): (The steps from step 6) Using the energy balance equation at time t as input, and substituting it into the heat conduction equation, we can calculate... Temperature field at any moment, combined Pressure distribution in the aerothermal environment parameters at any given time (Given quantities), using the corrected discrete database from step 5), interpolation can be performed to obtain... The dimensionless mass ablation rate at each surface node of the spacecraft at any given time, based on The dimensionless mass ablation rate at each surface node of the spacecraft at any given time and equation 4) are obtained Mass ablation rate of each surface node at any given time.
[0044] Step 8): Calculate the result from step 7). Substituting the mass ablation rate of each surface node at each time step The surface energy balance equation at time t, as The surface energy balance equation at time t is calculated. The temperature field and mass ablation rate at any given moment; this cycle continues until the flight ends.
[0045] This embodiment also provides a heterogeneous end-face ablation calculation system containing an ablation-resistant component, the system comprising: The first module is used to conduct state-tuning tests of electric arc wind tunnel using heat flux, pressure, and recovery enthalpy as state-of-the-art parameters. The orthogonal experiment yielded the following results: A database of mass ablation rates for individual samples; among which... It is a positive integer; The second module is used to establish an ablation calculation model; the ablation calculation model includes the element mass conservation equation, the gas partial pressure law equation, and the chemical reaction equation. The third module is used to substitute the preset temperature and pressure combination sequence into the ablation calculation model to obtain a discrete database of dimensionless mass ablation rate. The fourth module is used to determine the content of... A discrete database of experiments using a sample mass ablation rate database and a dimensionless mass ablation rate equation to obtain the dimensionless mass ablation rate. The fifth module is used to obtain the discrete database of the dimensionless mass ablation rate experiment using the least squares method, the correction coefficient matrix of the discrete database of the dimensionless mass ablation rate, and the corrected discrete database based on the correction coefficient matrix and the discrete database of the dimensionless mass ablation rate. The sixth module is used to establish The surface energy balance equation at time t; Module 7 is used to... Substituting the surface energy balance equation at time 1 into the heat conduction equation, we obtain... Temperature field at any time, according to Temperature field at any time, preset The pressure distribution in the aerothermal environment parameters at time t is obtained by interpolation with the corrected discrete database. The dimensionless mass ablation rate of each surface node of the spacecraft at any given time, based on The equations for the dimensionless mass ablation rate and dimensionless mass ablation velocity of each surface node of the spacecraft are obtained. Mass ablation rate of each surface node at any given time.
[0046] This embodiment also provides an electronic device, including: a memory for storing computer-readable instructions; and a processor for running the computer-readable instructions to execute a heterogeneous end-face ablation calculation method containing anti-ablation components.
[0047] In this embodiment, the ablation amount is calculated by interpolation based on the modified discrete database during the temperature field solution process, instead of solving the ablation equations (1) to (5) simultaneously for all unit nodes during the calculation process. Therefore, the calculation efficiency can be greatly improved.
[0048] This embodiment addresses different heat flows. ,pressure Enthalpy restoration The purpose of conducting short-duration, orthogonal wind tunnel tests is to obtain the ablation rates of samples under different conditions, forming a universal ablation database that can be used for interpolation under various flight conditions. In contrast, traditional design methods require long-duration (full-life) ablation tests for evaluation and verification under different flight conditions. Therefore, the one-time investment approach in this embodiment is more universal and less costly.
[0049] This embodiment quantifies the correlation between dimensionless mass ablation rate and temperature and pressure, and establishes a discrete point database of dimensionless mass ablation rate as a function of temperature and pressure. In the coupled ablation-temperature field solution process, the dimensionless mass ablation rate value is obtained by interpolation in the database based on temperature and pressure. This makes the calculation of the multivariate high-order equations of the thermochemical ablation equation system independent of the temperature field solution process, which can significantly improve the calculation efficiency.
[0050] This embodiment uses orthogonal wind tunnel test sample data to correct the temperature and pressure database of dimensionless mass ablation rate. The oxide film peeling data from real test results is used to correct the database of dimensionless mass ablation rate values. This avoids the need for mathematical modeling of the ablation process under conditions of oxide film formation and high-speed flow field scouring, and is more consistent with the real physical process.
[0051] In this embodiment, after quantifying the correlation between the dimensionless mass ablation rate and temperature and pressure, the established dimensionless mass ablation rate value is only a dependent variable of temperature and pressure, and only participates in the calculation of surface energy balance and final linear ablation rate. This improves the calculation efficiency and reduces the risk of calculation divergence. At the same time, the calculation result of the three-dimensional temperature field is used as the calculation parameter of the interpolated dimensionless mass ablation rate value, taking into account the influence of the three-dimensional heat transfer effect on the ablation calculation result, and the calculation accuracy is further improved.
[0052] This embodiment decouples the complex ablation temperature field coupling calculation process by establishing a general ablation database in advance, which greatly improves the calculation efficiency. At the same time, it avoids the practice of conducting a large number of wind tunnel ablation tests for different flight environments in the traditional design process, and significantly reduces the design cost.
[0053] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.
Claims
1. A method for calculating ablation of heterogeneous end faces containing ablation-resistant components, characterized in that... include: Step S1: Using heat flux, pressure, and recovery enthalpy as the state-based debugging parameters for the electric arc wind tunnel test, conduct... The orthogonal experiment yielded the following results: A database of mass ablation rates for individual samples; among which... It is a positive integer; Step S2: Establish an ablation calculation model; wherein, the ablation calculation model includes the element mass conservation equation, the gas partial pressure law equation, and the chemical reaction equation; Step S3: Substitute the preset temperature and pressure combination sequence into the ablation calculation model to obtain a discrete database of dimensionless mass ablation rate; Step S4: Based on containing A discrete database of experiments using a sample mass ablation rate database and a dimensionless mass ablation rate equation to obtain the dimensionless mass ablation rate. Step S5: Use the least squares method to obtain the discrete database of the dimensionless mass ablation rate test and the correction coefficient matrix of the discrete database of the dimensionless mass ablation rate. Based on the correction coefficient matrix and the discrete database of the dimensionless mass ablation rate, obtain the corrected discrete database. Step S6: Establish The surface energy balance equation at time t; Step S7: [The text appears to be incomplete and contains several grammatical errors. A more accurate translation would require the full context.] Substituting the surface energy balance equation at time 1 into the heat conduction equation, we get Temperature field at any time, according to Temperature field at any time, preset The pressure distribution in the aerothermal environment parameters at time t is obtained by interpolation with the corrected discrete database. The dimensionless mass ablation rate of each surface node of the spacecraft at any given time, based on The equations for the dimensionless mass ablation rate and dimensionless mass ablation velocity of each surface node of the spacecraft are obtained. Mass ablation rate of each surface node at any given time.
2. The method for calculating ablation of heterogeneous ends containing ablation-resistant components according to claim 1, characterized in that... It also includes: Substituting the mass ablation rate of each surface node at each time step The surface energy balance equation at time t is obtained The surface energy balance equation at each moment is repeated, and step S7 is repeated until the flight ends.
3. The method for calculating ablation of heterogeneous ends containing ablation-resistant components according to claim 1, characterized in that: The equation for the conservation of mass of elements is obtained through the following formula: ； in, , , The first The mass fraction of each chemical component at the outer edge of the boundary layer, on the material surface, and in the pyrolysis gas; For the first Molar mass of each chemical component; For the first The chemical component in the first The number of atoms in each gaseous component; To control the first Partial pressure of each gas component; , These are the dimensionless mass ablation rate and the dimensionless pyrolysis gas mass flow rate, respectively. The average molar mass of the mixed gas at the material surface control volume; To control the total pressure of the gas mixture, For gas component index, This is an index for chemical components.
4. The method for calculating ablation of heterogeneous ends containing ablation-resistant components according to claim 1, characterized in that: The law of partial pressures of gases is obtained through the following formula: ； in, To control the first Partial pressure of each gas component; To control the total pressure of the gas mixture, This is an index for gas components.
5. The method for calculating ablation of heterogeneous ends containing ablation-resistant components according to claim 4, characterized in that: The chemical reaction equation is obtained through the following formula: ； in, For temperature The equilibrium constant of this chemical reaction. The order of a chemical reaction. For gas component index, For temperature, This is the multiplication symbol.
6. The method for calculating ablation of heterogeneous ends containing ablation-resistant components according to claim 1, characterized in that: The dimensionless mass ablation rate equation is obtained through the following formula: ； in, The dimensionless mass ablation rate, The ablation rate is the percentage of material quality. To restore enthalpy at the end of the stationary point, For material density, The ejection factor, It is a hot flow through a cold wall.
7. The method for calculating ablation of heterogeneous ends containing ablation-resistant components according to claim 1, characterized in that: The surface energy balance equation at time t is obtained through the following formula: ； in, For the net heat flow into the material, For cold wall heat flow, For the surface emissivity of the material, It is the Stefan-Boltzmann constant; For mass ablation rate, For wall enthalpy, To restore enthalpy, The heat of ablation reaction, This refers to the wall temperature.
8. The method for calculating ablation of heterogeneous ends containing ablation-resistant components according to claim 7, characterized in that: ablation reaction heat The following conditions must be met: ； in, For the first The mass concentration of each chemical component at the wall surface For the first The heat of reaction of each chemical component The total number of chemical components. This is an index for chemical components.