Collision integral transport model custom interface design method

Abstract

The invention discloses a method for designing a custom interface of a collision integral transport model, and belongs to the technical field of numerical simulation of high-temperature and high-speed thermochemistry non-equilibrium flow. The method comprises the following steps: constructing a collision integral model UDF parameter file adapted to any component matching calculation situation; constructing a model parameter reading and analyzing interface based on a UDF parameter file of the collision integral transport model; constructing a mapping function interface; and modifying a UDF parameter file as well as a collision integral transport model and parameters associated with the UDF parameter file according to calculation requirements, and performing coupling calculation with a flow field solver to obtain a thermochemical non-equilibrium steady-state flow field and parameter distribution. The UDF user-defined parameter file established by the method can adapt to collision integral model parameter setting and efficient integration application requirements in various complex gas environments, has the advantages of high readability and expansion capability, flexibility in use and the like, and can meet the physical modeling requirements of the thermodynamic transport coefficient under any component combination condition.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-temperature and high-speed thermochemical non-equilibrium flow numerical simulation, and in particular relates to a method for designing a custom interface for a collision integral transport model. Background Art

[0002] In the process of conducting numerical simulations of high-temperature and high-speed thermochemical non-equilibrium flows, the high-temperature gas transport model is one of the important models that predict the accuracy of important aerodynamic characteristics such as aircraft aerodynamics and aerodynamic heat, and has an important impact on the integrated design of high-speed aircraft aerodynamic control, thermal protection, and communication systems. At present, high-temperature gas transport models can be divided into two categories: fitting approximation methods and collision integral methods. The former mainly approximates the viscosity coefficient, mass diffusion coefficient, and thermal conductivity coefficient of high-temperature gas based on empirical relationships or mathematical fitting formulas. Because the calculation formula is relatively simple, it is widely used in computational fluid dynamics (CFD). The latter is relatively complex to calculate, but it is supported by a strict physical mechanism, so the calculation accuracy is higher. Compared with the fitting approximation method, the collision integral method has a unified representation form, and the calculation of its viscosity coefficient, mass diffusion coefficient, and thermal conductivity coefficient all rely on the diffusion collision integral. and viscous collision integral Two key parameters. Among them, and Represents the collision pairs of components in a mixed gas.

[0003] Component collision pairs The diffusion collision integral and viscous collision integral are usually calculated using fitting polynomials. For inelastic (Coulomb) collisions, the collision integral calculation methods mainly include LAURA fitting formula, DPLR fitting formula and US3D fitting formula; for elastic (Coulomb) collisions, the collision integral calculation methods include Wright fitting formula, Gupta fitting formula, etc. Therefore, when programming, it is necessary to calculate the collision integral of each component. The calculation parameters are stored and preprocessed. At present, the commonly used simulation conditions are mainly air and Martian atmosphere, and the components involved are N, O, C, 、 、NO、CO、 Therefore, the component collision pairs in the program code The relevant fitting calculation parameters are clear and fixed, and usually two-dimensional arrays or three-dimensional arrays are used for parameter embedding and data storage.

[0004] However, with the increasing complexity of the gas environment in engineering applications, the gas components that need to be simulated have become more diverse and rich. The existing collision integral transport model database can no longer meet the needs of engineering calculations, and data integration using code embedding cannot adapt to the diverse calculation needs, which increases the difficulty of model parameter expansion and integration as well as the cost of code writing and maintenance management. There is an urgent need to develop a data storage structure and reading interface that is universal and flexible and convenient to expand and integrate. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for designing a custom interface for a collision integral transport model in response to the above-mentioned problems, hoping to improve the existing collision integral transport model database, which is unable to adapt to the computational requirements of diverse gas component combinations, and has the problems of difficulty in expanding and integrating simulation parameters, and high code writing and maintenance management costs.

[0006] The technical solution adopted by the present invention is as follows: a method for designing a custom interface for a collision integral transport model, the method specifically comprising the following steps: Step S100: constructing a UDF parameter file based on the collision integral transport model, wherein the components in the UDF parameter file can be arbitrarily matched; Step S200: Based on the UDF parameter file of the collision integral transport model, a parameter reading and parsing interface for parsing the collision integral model is constructed; Step S300: constructing a mapping function interface from the collision integral transport model obtained from the UDF parameter file to the collision integral transport model required for actual flow simulation; Step S400: Modify the UDF parameter file and its associated collision integral transport model and parameters according to calculation requirements, and obtain the thermochemical non-equilibrium steady-state flow field and parameter distribution through coupling calculation with the flow field solver.

[0007] Furthermore, step S100 specifically includes: Based on a variety of complex gas models, the common characteristics of the calculation parameters of the collision integral transport model are extracted and the UDF parameter file is established; UDF parameter files include I / O control variables, mixed gas composition, component collision pairs, and its fitting calculation parameter set.

[0008] Furthermore, step S200 specifically includes: Based on the UDF parameter file created in step S100, a storage data structure for the calculation parameters of the analytical collision integral model is constructed, and a matching I / O member function is established to uniformly design and manage the I / O analytical interface.

[0009] Furthermore, step S300 specifically includes: A mapping function interface is constructed from the collision integral transport model obtained from the UDF parameter file to the collision integral transport model required for actual flow simulation. According to the composition and order of the mixed gas components provided by the master control parameter file, the optimized and reorganized collision integral transport model parameters are obtained through the mapping function interface conversion, which is used to perform iterative solution of thermochemical non-equilibrium flow in the high-temperature non-equilibrium CFD solver.

[0010] Furthermore, step S400 specifically includes: The modified UDF parameter file and its associated collision integral transport model and parameters are applied to the numerical iteration process of the high-temperature non-equilibrium CFD solver to update the thermodynamic transport coefficients of the mixed gas components until the convergence conditions are met to obtain the final required thermochemical non-equilibrium steady-state flow field and parameter distribution.

[0011] Furthermore, five parameters are added to the I / O control variable element, and the five newly added parameters are placed in the first five lines of the UDF parameter file for memory pre-allocation and parameter reading control.

[0012] The five parameters are: species_num, pair_num, collision_mode, diff_fit_num, and vis_fit_num.

[0013] Furthermore, for the component collision of UDF parameter file And its fitting calculation parameter set part, a set of component collision pairs contains 2 lines of data information, namely component collision pairs A detailed list of component names and their fitting calculation parameter sets.

[0014] Furthermore, the UDF parameter file allows component collision pairs The reuse of data, the collision of the same components Data replaces the first component collision pair Data; and component collision pairs and component collision pairs for the same set of collisions.

[0015] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The custom interface design method for the collision integral transport model provided by the present invention adopts a custom UDF parameter file with a standardized format and flexible editing, and its parsing interface design to solve the programming redundancy and low reusability problems caused by traditional embedded module coding and data integration expansion methods, greatly reducing the difficulty of parameter model expansion and integration, and meeting the needs of "lightweight" code writing and maintenance management of computing modules.

[0016] 2. The UDF custom parameter file proposed and established in this invention can adapt to the parameter setting and efficient integrated application requirements of the collision integral model under various complex gas environments. It has the advantages of strong readability, expansion capability, and flexible use. It can meet the broad needs of basic scientific research such as the physical modeling of thermodynamic transport coefficients under the calculation conditions of arbitrary component combinations and their impact on the aerodynamic thermal environment of high-speed aircraft.

[0017] 3. The custom interface design method for the collision integral transport model proposed and established in the present invention is applicable to a variety of complex gas models including the Earth's atmosphere, the Martian atmosphere, high-temperature combustion gas, ablation ejection gas, etc., and can meet the application requirements of thermochemical non-equilibrium flow simulation in complex gas environments and calculation and analysis of related aerodynamic characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Flow chart of the method of the present invention; Figure 2 This is a schematic diagram of the input function flow chart of the collision integral model UDF parameter file reading of the present invention; Figure 3 Schematic diagram of the design of the interface for optimizing the reorganization mapping function for the collision integral model; Figure 4 This is a comparison diagram of the wall pressure distribution calculated based on the HEG shock tunnel cylindrical model in Example 1; Figure 5 This is a comparison diagram of the wall heat flux distribution calculated based on the HEG shock tunnel cylindrical model for Example 2. DETAILED DESCRIPTION

[0019] The present invention will be described in detail below with reference to the accompanying drawings.

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] like Figure 1 As shown, a method for designing a custom interface for a collision integral transport model comprises the following steps: Step S100: constructing a UDF parameter file based on the collision integral transport model. The components in the UDF parameter file can be arbitrarily matched for calculation, generally in pairs. Based on a variety of complex gas models, such as the Earth's atmosphere, Martian atmosphere, high-temperature combustion gas, and ablation-induced gas, the common characteristics of the calculation parameters of the collision integral transport model are extracted, and a UDF parameter file with a standardized format, flexible editing, and easy reuse is established to realize the human-computer interactive parameter setting function.

[0022] Among them, for the gas models commonly used in engineering, such as the Earth's atmosphere, the Martian atmosphere, high-temperature combustion gas, and ablation ejection gas, the collision integral transport model mainly includes the following three types of information in the parameter system construction, namely, I / O control variables, mixed gas component composition, component collision, and so on. The parameters of the Earth's atmosphere are as follows: 、NO、N、 ) gas model as an example, the design style of the UDF parameter file of the general collision integral transport model is shown in Table 1.

[0023] Table 1 UDF parameter file format for the general collision integral transport model

[0024] As can be seen in Table 1, the collision integral transport model UDF parameter file adds five parameters to the I / O control variable section: species_num, pair_num, collision_mode, diff_fit_num, and vis_fit_num. These parameters are placed in the first five lines of the file for memory preallocation. The specific meanings and comments of the five parameters are shown in Table 1.

[0025] The sixth line gives a list of the names of the mixed gas components. The names of the components are separated by spaces or commas for easy identification and reading. Secondly, the order of the components can be arranged and adjusted arbitrarily, and can also be expanded, added, deleted or reduced according to calculation needs. This can maximize the flexibility of model modification and updating.

[0026] Further, each component collision pair is described in detail in each of the following two lines. The first line gives the names of the components involved in the collision, and the next line gives the set of fitting calculation parameters for the collision integral. The two components involved in the collision, namely O and O, are listed in detail in the next line. Among them, the component symbols are separated by spaces or commas for easy identification and reading; in addition, there are usually 8 collision integral fitting calculation parameters for the inelastic Coulomb collision type (determined by the two parameters diff_fit_num=4 and vis_fit_num=4), which include 2 parts. The first 4 values ​​(the specific number is determined by the diff_fit_num parameter) are the diffusion collision integral fitting calculation parameters of the collision pair OO, and the last 4 values ​​(the specific number is determined by the vis_fit_num parameter) are the viscous collision integral fitting calculation parameters of the collision pair OO. For the Coulomb collision type, the fitting calculation parameters for the diffusion collision integral and the viscous collision integral are diff_fit_num=3 and vis_fit_num=3 respectively. For collision pairs of other components This example is given in sequence.

[0027] It is worth noting that: component collision The order of information listing is not fixed and can be written arbitrarily according to the user's own needs. For example, the data information of lines 7-8 can be adjusted to any position after line 9, but be careful not to affect the integrity of other component collision pair information. That is, a group of collision pairs contains 2 lines of data information, namely, collision pairs A detailed list of component names and their fitting calculation parameter sets is provided. Therefore, when users need to expand or reduce the number of mixed gases, adding relevant entries or deleting irrelevant collision pair entries will be more flexible and will not be affected by the inherent sorting. This also improves the reusability of the component collision pair fitting calculation parameters.

[0028] In addition, the UDF parameter file allows component collision pairs The data is reused, but the last data will be used as the reference. The previous data will be replaced by the following data. For example, its data information first appears in rows 9-10 of Table 1. If two more rows are added to the end of Table 1 to also describe the component collisions of O- If the parameter information is not provided, then the data information of the last two rows will be used when the data is used. The data of No. 9-10 will be replaced. In fact, it is equivalent to using the data at the end to collide with O- This operation is also possible due to the high reusability and scalability of the UDF parameter file design.

[0029] At the same time, there is no ordering of components in the component collision pairs. and component collision pair j-i are considered as the same group of collisions, and their collision integral fitting calculation parameters are considered as the same group of data information. For example, component collision pair O- and component collision pair are considered as the same group of collisions, and thus, “O- ” and “ -O” are related fitting calculation parameters, which are considered as the same group of data information in the UDF parameter file. If similar information content of component collision pair -O appears in the subsequent part of the UDF parameter file, the data parameters of the aforementioned component collision pair O- will be replaced by the data of component collision pair -O.

[0030] Step S200: Based on the UDF parameter file of the collision integral transport model, a parameter reading and parsing interface of the analytical collision integral model is constructed; based on the UDF parameter file established in step S100, a storage data structure of the calculation parameters of the analytical collision integral model is constructed, and a matching I / O member function is established, the I / O parsing interface is uniformly designed and managed, and the association and conversion between the calculation storage data and the UDF parameter file are realized.

[0031] Based on the UDF parameter file design method of step S100, the object-oriented program design idea is adopted, the CollisionIntegralData class data structure of the collision integral model is designed, and the I / O parsing interface is unified; the member variables and functions of the CollisionIntegralData class are shown in Table 2: Table 2 Member variables and functions of the CollisionIntegralData class of the chemical reaction model

[0032] For example, Figure 2As shown, based on the UDF parameter file described in step S100 and the collision integral model CollisionIntegralData class data structure, the I / O interface function first obtains the total number of mixed gas components, species_num, the total number of component collision pairs, pair_num, the component collision type, collision_mode, the number of diffusion collision integral fitting calculation parameters, diff_fit_num, and the number of viscous collision integral fitting calculation parameters, vis_fit_num, and assigns values ​​to the member variables of the CollisionIntegralData class, namely, nSpecies = species_num, nCollisionMode = collision_mode, nFitNum1 = diff_fit_num, and nFitNum2 = vis_fit_num. The data structure of the collision integral fitting calculation parameters uses a three-dimensional array. Since the maximum number of valid component collision pairs is nSpecies(nSpecies+1) / 2, using a three-dimensional array data structure wastes data space, but it increases the convenience of parameter use and maintains consistency with the storage method of flow field parameters. In addition, the number of valid component collision pairs is related to the number of components. Therefore, the parameter pair_num does not need to be separately allocated as a member variable in the CollisionIntegralData class to record it. Instead, it can be used as a temporary variable to constrain the reading process of the UDF parameter file.

[0033] Next, initialize the array space according to the above parameters. The size of the one-dimensional array speciesName is nSpecies, the sizes of each dimension of the three-dimensional array curveFitOmega11 are nSpecies, nSpecies, and nFitNum1, respectively, and the sizes of each dimension of the three-dimensional array curveFitOmega22 are nSpecies, nSpecies, and nFitNum2, respectively.

[0034] Next, read the name of each component and store them in the array speciesName. Then loop through each component collision pair according to the pair_num parameter. and its fitting calculation parameters. The collision component numbers (i and j) in the three-dimensional array space are obtained based on the component name string. The corresponding fitting calculation parameters are then stored in the corresponding spaces of the three-dimensional arrays curveFitOmega11 and curveFitOmega22.

[0035] Step S300: Construct a mapping function interface from the collision integral transport model obtained from the UDF parameter file to the collision integral transport model required for actual flow simulation. According to the composition and order of the mixed gas components provided by the master control parameter file, the optimized and reorganized collision integral transport model parameters are obtained through the mapping function interface conversion, which are used to perform iterative solution of thermochemical non-equilibrium flow in the high-temperature non-equilibrium CFD solver.

[0036] This embodiment uses 5 components (0, 、NO、N、 ) gas model as an example, if the mixed gas for flow simulation contains only O and If the calculation is still based on the five-component model, NO, N, The storage space and computational time consumed by the three redundant components do not contribute to improving computational efficiency. Therefore, a program design incorporates an optimized reorganization mapping function interface from the complete collision integral model parameter system to the minimized collision integral model parameter system. This removes redundant components and irrelevant component collision pair parameter information, generating a simplified collision integral model and its parameter system, which can then be used and controlled by the high-temperature non-equilibrium CFD solver. The optimized and reorganized collision integral model (i.e., simplified parameter model) is shown in Table 3. As can be seen, the number of gas mixture components has been reduced by three and the number of component collision pairs has been reduced by 12, significantly improving storage space and computational efficiency.

[0037] Table 3 Parameter file format of the two-component collision-integrated transport model generated by the simplified mapping of the five-component gas model

[0038] like Figure 3 As shown in the figure, users can arbitrarily delete the composition of the mixed gas components and reorganize the component order according to the parameter settings of the master control file, thereby obtaining a simplified collision integral model with different component combinations. Therefore, this mapping function interface design makes the collision integral model more diverse and its use more free and flexible.

[0039] Step S400: Modify the UDF parameter file and its associated collision integral transport model and parameters according to calculation requirements, and obtain the thermochemical non-equilibrium steady-state flow field and parameter distribution through coupling calculation with the flow field solver.

[0040] According to the calculation conditions, the modified UDF parameter file and its associated collision integral transport model and parameters are applied to the numerical iteration process of the high-temperature non-equilibrium CFD solver to update the thermodynamic transport coefficients of the mixed gas components until the convergence conditions are met to obtain the final required thermochemical non-equilibrium steady-state flow field and parameter distribution.

[0041] Thermodynamic transport coefficients mainly include viscosity coefficient, heat conductivity coefficient and mass diffusion coefficient, and flow field parameter distribution includes wall pressure and heat flux density.

[0042] The thermochemical non-equilibrium flow control equation involved in the high-temperature non-equilibrium CFD solver adopts the conservative integral form: ; in, 、 represent the control volume and its enclosing surface respectively, is the volume of the control unit, is the area of ​​the flow surface, is the normal vector of the flow surface, is the incoming flow Reynolds number, is the conserved quantity vector, and are the convective flux and viscous flux, respectively, is the non-equilibrium source term, For time.

[0043] Conserved quantity vector , convective flux , viscous flux and non-equilibrium source terms The specific expression is:

[0044] in, Is the flow surface area The normal vector of , are normal vectors The components in the directions of each coordinate axis, is the absolute velocity of the fluid, , are the component values ​​of the velocity in the directions of each coordinate axis; The components in the mixed gas are The mass fraction, specific enthalpy, vibration energy and mass diffusion coefficient of , is the total number of gas mixture components, are the density, pressure and temperature of the mixed gas respectively, is the total enthalpy of the mixed gas, is the vibration energy and total internal energy of the mixed gas, are the translational modal heat conductivity coefficient and vibration modal heat conductivity coefficient of the mixed gas, For components The chemical reaction generates the source term, is the vibration non-equilibrium source term; is the viscous stress tensor, The individual component values of the viscous stress tensor are denoted by The following formula is satisfied: ; wherein is the viscosity coefficient of the mixture gas, are the velocity component values in the three coordinate directions of the Cartesian coordinate system .

[0045] The specific correlation of the energy system of the mixture gas is: ; wherein are the density, pressure, total specific internal energy and enthalpy value of the mixture gas, respectively, are the translational energy and vibrational energy of the mixture gas, respectively.

[0046] The viscosity coefficient, thermal conductivity coefficient and mass diffusion coefficient of the mixture gas are calculated by the collision integral model, and the calculation formula of the viscosity coefficient of the mixture gas is: ; wherein is the electronic component, is the mass of a single particle (unit: kg), , is the serial number of the gas component in the set, is the molar mass of the molecule, is the Avogadro constant, is the molar concentration (unit: mol / kg) of the gas component , , is the mass fraction of the gas component , denote the translational temperature and the electronic temperature (unit: K), respectively, denote the viscous collision integral term (unit: ) of the component collision pair , denote the viscous collision integral term (unit: ) of the component collision pair , denote the viscous collision integral term (unit: ) of the component collision pair .

[0047] The thermal conductivity coefficients of the translational energy and the rotational energy and are respectively: ; wherein,​ For electronic components, is a polyatomic component or molecule, is the Boltzmann constant, , For gas components The molar concentration (unit: mol / kg), Represents component collision pairs The diffusion collision integral term (unit: ), Represents component collision pairs The diffusion collision integral term (unit: ), Represents component collision pairs The viscous collision integral term (unit: ), Represents component collision pairs The viscous collision integral term (unit: ).

[0048] coefficient Defined as: ; in, is the mass ratio, For gas components The mass of a single particle (unit: kg), For gas components The mass of a single particle (unit: kg), For gas components The molar mass of For gas components The molar mass of .

[0049] Thermal conductivity of vibrational energy and electronic energy and They are: ; in, is the universal gas constant, is the average molecular weight of the mixed gas, is the vibration constant volume specific heat of the mixed gas, is the heat transfer coefficient of rotational energy, is the Boltzmann constant, , is the molar concentration of electrons (unit: mol / kg), is the electron temperature, is the average molecular weight of the mixed gas, is the electronic constant volume specific heat of the mixed gas, Represents component collision pairs The diffusion collision integral term (unit: ).

[0050] Components The equivalent mass diffusion coefficient for: ; in, For gas components The molar concentration (unit: mol / kg).

[0051] Diffusion collision integral term and the viscous collision integral term Use the following formula to calculate: ; in, and is the component number, 、 The gas components and The molecular molar mass of Represents component collision pairs The diffusion collision integral or diffusion collision cross section (unit: m2), Represents component collision pairs The viscous collision integral or viscous collision cross section (unit: m2).

[0052] For inelastic collision types, the diffuse collision integral and viscous collision integral The fitting method is calculated as follows: ; Among them, the fitting coefficient 、 、 、 、 、 、 、 They are determined by the collision integral fitting calculation parameters in the UDF parameter file.

[0053] The LU-SGS numerical format is used to discretize and iteratively solve the thermochemical non-equilibrium flow control equations. When the average residual tends to be stable or reaches the maximum number of iterations, the flow field calculation is considered to have converged, thereby obtaining various parameters of the chemical non-equilibrium steady flow, such as the wall pressure distribution value and the wall heat flux distribution value. The LU-SGS numerical iteration format is expressed as: ; ; Among them, the superscript is the calculation time, * is the intermediate calculation amount, is the right-hand side term, L, D, and U are lower triangular matrix, diagonal matrix, and upper triangular matrix respectively. Add value to the temporary conserved quantity, For the current The conserved quantity calculated at each moment increases in value.

[0054] Example 1 like Figure 4-Figure 5 As shown, one embodiment of the present invention is a custom interface design method for a collision integral transport model, which is applied to a high-temperature non-equilibrium CFD solver to set collision integral model parameters and calculate thermodynamic transport coefficients such as viscosity coefficient, heat conductivity coefficient and mass diffusion coefficient. At the same time, high-temperature and high-speed chemical non-equilibrium flow simulation is carried out based on the HEG shock wave wind tunnel cylindrical model. The calculation model and experimental conditions refer to the existing calculation model and experimental conditions.

[0055] The complete 14-component collision integral model (O / / NO / N / / / / / / / / C / CO / ) input, the numerical simulation uses thermodynamic single temperature 5 components (O / / NO / N / ) The Dunn-Kang chemical model was used, the Steger scheme and Minmod limiter were selected for the convective flux, the Courant number (CFL number) was 200, the isothermal fully catalytic wall condition (wall temperature 300 K) was adopted for the wall boundary, and the single-core serial iteration step was 10,000.

[0056] Figure 4 and Figure 5 A comparison of the wall pressure and heat flux distributions calculated using different methods is presented. The figure shows that the wall pressure curve calculated using the present method is consistent with that obtained using the fitting calculation method. However, compared to experimental data, the fitting calculation method achieves higher accuracy in predicting heat flux distribution. This verifies the correctness and effectiveness of the collision integral transport model UDF parameter file and its analytical I / O interface constructed in this invention, demonstrating that the collision integral model interface design method described in this invention can meet the application requirements of chemical reaction flow simulations related to complex flight environments.

[0057] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for designing a custom interface for a collision integral transport model, characterized in that: The method specifically includes the following steps: Step S100: constructing a UDF parameter file based on a collision integral transport model, wherein the components in the UDF parameter file can be arbitrarily matched; Step S200: Based on the UDF parameter file of the collision integral transport model, a parameter reading and parsing interface for parsing the collision integral model is constructed; Step S300: constructing a mapping function interface from the collision integral transport model obtained from the UDF parameter file to the collision integral transport model required for actual flow simulation; Step S400: Modify the UDF parameter file and its associated collision integral transport model and parameters according to calculation requirements, and obtain the thermochemical non-equilibrium steady-state flow field and parameter distribution through coupling calculation with the flow field solver.

2. A method for designing a custom interface for a collision integral transport model according to claim 1, characterized in that: Step S100 specifically includes: Based on a variety of complex gas models, the common characteristics of the calculation parameters of the collision integral transport model are extracted and the UDF parameter file is established; UDF parameter files include I / O control variables, mixed gas composition, component collision pairs, and its fitting calculation parameter set.

3. The method for designing a custom interface for a collision integral transport model according to claim 1, characterized in that: Step S200 specifically includes: Based on the UDF parameter file created in step S100, a storage data structure for the calculation parameters of the analytical collision integral model is constructed, and a matching I / O member function is established to uniformly design and manage the I / O analytical interface.

4. The method for designing a custom interface for a collision integral transport model according to claim 1, characterized in that: Step S300 specifically includes: A mapping function interface is constructed from the collision integral transport model obtained from the UDF parameter file to the collision integral transport model required for actual flow simulation. According to the composition and order of the mixed gas components provided by the master control parameter file, the optimized and reorganized collision integral transport model parameters are obtained through the mapping function interface conversion, which is used to perform iterative solution of thermochemical non-equilibrium flow in the high-temperature non-equilibrium CFD solver.

5. The method for designing a custom interface for a collision integral transport model according to claim 1, characterized in that: Step S400 specifically includes: The modified UDF parameter file and its associated collision integral transport model and parameters are applied to the numerical iteration process of the high-temperature non-equilibrium CFD solver to update the thermodynamic transport coefficients of the mixed gas components until the convergence conditions are met to obtain the final required thermochemical non-equilibrium steady-state flow field and parameter distribution.

6. The method for designing a custom interface for a collision integral transport model according to claim 2, characterized in that: Five parameters are added to the I / O control variable element and placed in the first five lines of the UDF parameter file for memory pre-allocation and parameter reading control.

7. The method for designing a custom interface for a collision integral transport model according to claim 2, characterized in that: Component collision pairs for UDF parameter files And its fitting calculation parameter set part, a set of component collision pairs contains 2 lines of data information, namely component collision pairs A detailed list of component names and their fitting calculation parameter sets.

8. The method for designing a custom interface for a collision integral transport model according to claim 7, characterized in that: The UDF parameter file allows the collision of components The reuse of data, the collision of the same components Data replaces the first component collision pair Data; and component collision pairs and component collision pairs For the same set of collisions.

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