A method and system for analyzing the thermal radiation of a launch vehicle engine jet

Abstract

A method for analyzing the thermal radiation of a launch vehicle engine jet comprises: establishing a local coordinate system containing a coordinate origin and coordinate directions; performing surface and volume meshing based on the local coordinate system; calculating the gas spectral absorption coefficient for each node in the volume mesh based on a spectral absorption coefficient database and input flow field parameters; calculating the spectral scattering cross section and spectral absorption cross section based on the spectral scattering factor, spectral absorption factor, and diameter of solid particles; and calculating the spectral absorption coefficient and spectral scattering coefficient of the solid particles in combination with the solid particle number density; and calculating the jet thermal radiation density using a reverse Monte Carlo simulation method based on the gas spectral absorption coefficient and the solid particle spectral absorption coefficient and spectral scattering coefficient. Through surface and volume meshing, and automatically invoking gas radiation characteristic calculation programs, particle radiation characteristic calculation programs, and engine thermal radiation calculation programs, the engine radiation characteristic analysis is completed.

Description

Technical Field

[0001] The present invention belongs to the technical field of aerospace thermal environment prediction, and in particular relates to a method and system for analyzing jet thermal radiation of a carrier rocket engine. Background Art

[0002] Throughout the development of launch vehicles, the thermal environment of the engine jet has always been a key concern, crucial to the success of a launch vehicle. Thermal radiation from the high-temperature jet medium is a crucial component of the engine's thermal environment, determining its magnitude and dynamics. In particular, Al₂O₃ solid particles contained in the hot, high-speed airflow discharged from solid rocket motors significantly increase the jet's thermal radiation. This also affects the flow field distribution of the airflow at the base of the rocket, causing exhaust cross-effects and additional interference between the booster and main engine flames. This intensifies the interaction between the solid motor plume and the liquid core stage plume, further studying the jet's thermal radiation characteristics.

[0003] To accurately characterize the thermal environment of the engine jet, numerous scaled-down or full-scale tests have been conducted abroad. For example, during the development of the Delta I and Titan III rockets, the United States conducted ground-based wind tunnel tests of the bottom thermal environment, examining the changing trends in heat flux across different regions of the engine jet. During the development of the Ariane 5, the European Union conducted scaled-down wind tunnel jet visualization tests of the engine jet flow patterns for the core stage and solid booster nozzles. These tests are labor-intensive, material-intensive, and financially intensive, and fail to accurately simulate the engine jet thermal environment throughout the entire flight. Ground-based tests of rocket bottom thermal conditions are costly and difficult to conduct. Summary of the Invention

[0004] To solve the above problems, the purpose of the present invention is to establish a method and system for analyzing the jet thermal radiation of a launch vehicle engine based on the RMC method. The engine radiation characteristics analysis is completed through surface mesh division, volume mesh division, and automatic backend call of gas radiation characteristics calculation, particle radiation characteristics calculation and engine thermal radiation calculation programs.

[0005] To achieve the above object, the technical solution of the present invention is:

[0006] A method for analyzing the thermal radiation of a launch vehicle engine jet comprises: establishing a local coordinate system including a coordinate origin and a coordinate direction, and performing surface meshing and volume meshing based on the local coordinate system; calculating the gas spectral absorption coefficient of each node in the volume mesh based on a spectral absorption coefficient database and input flow field parameters; calculating the spectral scattering cross section and the spectral absorption cross section based on the spectral scattering factor, spectral absorption factor, and solid particle diameter of solid particles, and calculating the spectral absorption coefficient and spectral scattering coefficient of the solid particles in combination with the solid particle number density; and simulating and calculating the jet thermal radiation density using a reverse Monte Carlo method based on the gas spectral absorption coefficient and the spectral absorption coefficient and spectral scattering coefficient of the solid particles.

[0007] In one embodiment of the present invention, after the jet thermal radiation density is calculated by using the reverse Monte Carlo method, the method further includes: storing process data and input data during the operation of the analysis method; and displaying the process data and input data according to a preset mode.

[0008] In one embodiment of the present invention, the surface mesh division and volume mesh division based on the local coordinate system include: inputting the coordinate system definition, surface equation, surface normal direction, surface mesh division method, surface temperature, solid wall emissivity, and the interface between surfaces; performing surface network division based on the coordinate system definition, surface equation, surface normal direction, surface mesh division method, surface temperature, solid wall emissivity, and the interface between surfaces; inputting the volume mesh area and mesh division rules, and dividing the three-dimensional volume mesh inside the area based on the volume area composed of each surface.

[0009] In one embodiment of the present invention, the method of obtaining the gas spectral absorption coefficient of each node in the volume grid based on the spectral absorption coefficient database and the input flow field parameters includes: calling the spectral absorption coefficient of the target gas at the target wavenumber and target temperature in the spectral absorption coefficient database of different gases at different wavenumbers (HITRAN and HITEMP databases); performing difference calculation on the target node parameters to obtain the spectral absorption coefficients of different gases; and integrating the spectral absorption coefficients of different gases to obtain the gas spectral absorption coefficient of the target node.

[0010] In one embodiment of the present invention, the calculation of the spectral scattering cross section and the spectral absorption cross section based on the spectral scattering factor, spectral absorption factor and solid particle diameter of the solid particles, and the calculation of the spectral absorption coefficient and spectral scattering coefficient of the solid particles in combination with the solid particle number density include: obtaining the refractive index and absorption coefficient of the solid particles, and using Mie scattering theory to calculate their spectral scattering factor and spectral absorption factor; calculating the spectral scattering cross section and spectral absorption cross section based on the spectral heat dissipation factor and spectral absorption factor of the solid particles in combination with the solid particle diameter; and calculating the spectral absorption coefficient and spectral scattering coefficient of the solid particles based on the spectral scattering cross section and spectral absorption cross section in combination with the solid particle number density.

[0011] In one embodiment of the present invention, the jet thermal radiation density is calculated based on the gas spectral absorption coefficient and the solid particle spectral absorption coefficient and spectral scattering coefficient using the reverse Monte Carlo method, including: obtaining the gas spectral absorption coefficient and the solid particle spectral absorption coefficient and spectral scattering coefficient; obtaining grid information and light ray information to determine the incident point of the light entering the jet flow field; simulating the transmission of light in the flow field and the process of attenuation events through a probability model, and outputting the simulation results to obtain the jet thermal radiation density.

[0012] Based on the same concept, the present invention also provides a launch vehicle engine jet thermal radiation analysis system, including: a grid division module, used to establish a local coordinate system including a coordinate origin and a coordinate direction, and perform surface grid division and volume grid division based on the local coordinate system; a gas radiation characteristic calculation module, used to obtain the gas spectral absorption coefficient of each node in the volume grid based on the spectral absorption coefficient database and the input flow field parameters; a particle radiation characteristic calculation module, used to calculate the spectral scattering cross section and spectral absorption cross section based on the spectral scattering factor, spectral absorption factor and solid particle diameter of the solid particles, and calculate the spectral absorption coefficient and spectral scattering coefficient of the solid particles in combination with the particle number density; a heat flux density calculation module, used to simulate and calculate the jet thermal radiation density based on the gas spectral absorption coefficient and the spectral absorption coefficient and spectral scattering coefficient of the solid particles using the inverse Monte Carlo method.

[0013] In one embodiment of the present invention, a data management module is further included, which is used to store process data and input data during the operation of the analysis method and display the process data and input data according to a preset mode.

[0014] Based on the same concept, the present invention also provides an electronic device, comprising: a memory for storing a processing program; and a processor for implementing any one of the above-mentioned methods for analyzing the jet thermal radiation of a carrier rocket engine when executing the processing program.

[0015] Based on the same concept, the present invention also provides a readable storage medium, on which a processing program is stored. When the processing program is executed by a processor, any one of the above-mentioned methods for analyzing the jet thermal radiation of a carrier rocket engine is implemented.

[0016] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art:

[0017] 1. The engine radiation characteristics analysis is completed through surface mesh division, volume mesh division, and automatic calling of gas radiation characteristics calculation, particle radiation characteristics calculation and engine thermal radiation calculation programs in the background.

[0018] 2. Based on the jet flow field parameters and the database of spectral absorption coefficients of different gases in different spectral bands, the gas spectral absorption coefficients of each node in the jet are calculated to provide input for the subsequent calculation of the gas radiation heat flux density, which can improve the accuracy of characteristic analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein:

[0020] Figure 1 This is a flow chart of the carrier rocket engine jet thermal radiation analysis method of the present invention;

[0021] Figure 2 Schematic diagram of the reverse Monte Carlo tracking process of the present invention;

[0022] Figure 3 It is a diagram of the light transmission and attenuation process; DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are greatly simplified and not to exact ratios, and are intended solely to facilitate and clearly illustrate the embodiments of the present invention.

[0024] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0025] First embodiment

[0026] like Figure 1An embodiment of the present invention provides a method for analyzing the thermal radiation of a launch vehicle engine jet, comprising: establishing a local coordinate system including a coordinate origin and a coordinate direction, and performing surface meshing and volume meshing based on the local coordinate system; calculating the gas spectral absorption coefficient of each node in the volume mesh based on a spectral absorption coefficient database and input flow field parameters; calculating the spectral scattering cross section and the spectral absorption cross section based on the spectral scattering factor, spectral absorption factor and solid particle diameter of the solid particles, and calculating the spectral absorption coefficient and spectral scattering coefficient of the solid particles in combination with the solid particle number density; and using the inverse Monte Carlo method to simulate and calculate the jet thermal radiation density based on the gas spectral absorption coefficient and the spectral absorption coefficient and spectral scattering coefficient of the solid particles.

[0027] The engine radiation characteristics analysis is completed through surface mesh division, volume mesh division, and automatic calling of gas radiation characteristics calculation, particle radiation characteristics calculation and engine thermal radiation calculation programs in the background.

[0028] In one embodiment of the present invention, after the jet thermal radiation density is calculated by using the reverse Monte Carlo method, the method further includes: storing process data and input data during the operation of the analysis method; and displaying the process data and input data according to a preset mode.

[0029] After the calculation is complete, the system automatically stores and displays the radiation according to the receiving points, including the gas radiation component, particle radiation component, solid surface radiation component, and the radiation proportion of each component. It can be displayed in the form of a bar chart.

[0030] As an embodiment, the above data may be displayed in the form of a data table, and may also be selectively displayed according to the user's choice.

[0031] In one embodiment of the present invention, the surface mesh division and volume mesh division based on the local coordinate system include: inputting the coordinate system definition, surface equation, surface normal direction, surface mesh division method, surface temperature, solid wall emissivity, and the interface between surfaces; performing surface network division based on the coordinate system definition, surface equation, surface normal direction, surface mesh division method, surface temperature, solid wall emissivity, and the interface between surfaces; inputting the volume mesh area and mesh division rules, and dividing the three-dimensional volume mesh inside the area based on the volume area composed of each surface.

[0032] Among them, the 10-coefficient equation is used to define the surface equation, determine the surface type, normal direction, temperature, emissivity, the number of surface grids, determine the boundary lines between surfaces, and finally each surface grid forms a closed area.

[0033] Furthermore, based on the volumetric regions formed by the combined faces, a 3D volumetric mesh is created within the region. Volumetric meshing is achieved by setting the volumetric mesh region and meshing principles. This ultimately generates a file containing mesh node coordinates, mesh volume, and vertex coordinates in the local coordinate system for use in radiation calculations.

[0034] In one embodiment of the present invention, the method of obtaining the gas spectral absorption coefficient of each node in the volume grid based on the spectral absorption coefficient database and the input flow field parameters includes: calling the spectral absorption coefficient of the target gas at the target wavenumber and target temperature in the HITRAN and HITEMP databases; performing difference calculation on the target node parameters to obtain the spectral absorption coefficients of different gases; and integrating the spectral absorption coefficients of different gases to obtain the gas spectral absorption coefficient of the target node.

[0035] Based on the jet flow field parameters and a database of spectral absorption coefficients for different gases in different spectral bands, the spectral absorption coefficients of the gases at each node in the jet were calculated, providing input for the subsequent calculation of the gas radiation heat flux density. Based on the HITRAN and HITEMP databases, a narrow-band model was used to calculate the thermal radiation characteristics of the jet gases. A spectral range of 2.2 μm to 200 μm was determined, essentially covering the entire range of infrared radiation. Furthermore, the average absorption coefficient within these narrow bands was obtained, with one band for every 25 wavenumbers, for a total of 178 bands.

[0036] In the above process, the main input jet flow field parameters include: number of internal nodes, X / Y / Z coordinates, static pressure, static temperature, molar fraction of each component; gas radiation control parameters include: number of band segments, starting band, band width, and number of bands within each width. The main output parameter is the spectral absorption coefficient of each node.

[0037] By calling the spectral absorption coefficient of the target gas at the target wavenumber and target temperature in the HITRAN and HITEMP databases, the impact of factors such as different gas compositions, different pressures, and different temperatures on the accuracy of the system can be maximized.

[0038] In one embodiment of the present invention, the calculation of the spectral scattering cross section and the spectral absorption cross section based on the spectral scattering factor, spectral absorption factor and solid particle diameter of the solid particles, and the calculation of the spectral absorption coefficient and spectral scattering coefficient of the solid particles in combination with the solid particle number density include: obtaining the refractive index and absorption coefficient of the solid particles, and using Mie scattering theory to calculate their spectral scattering factor and spectral absorption factor; calculating the spectral scattering cross section and spectral absorption cross section based on the spectral heat dissipation factor and spectral absorption factor of the solid particles in combination with the solid particle diameter; and calculating the spectral absorption coefficient and spectral scattering coefficient of the solid particles based on the spectral scattering cross section and spectral absorption cross section in combination with the solid particle number density.

[0039] The main focus is on Al2O3 solid particles in solid fuel injection combustion products. The spectral absorption and scattering coefficients of Al2O3 solid particles in the jet flow field are calculated to provide technical input for the particle radiation calculation module in the radiation heat flux density calculation module. The refractive index and absorption coefficient of Al2O3 solid particles are determined based on existing public literature. The main input parameters of the jet flow field are: number of internal nodes, X / Y / Z coordinates, particle inlet unit coordinates, particle velocity vector parameters, particle temperature, particle diameter, and particle number density at each node. The main output parameters are the absorption and scattering coefficients of the particles at each node.

[0040] In one embodiment of the present invention, the jet thermal radiation density is calculated based on the gas spectral absorption coefficient and the solid particle spectral absorption coefficient and spectral scattering coefficient using the reverse Monte Carlo method, including: obtaining the gas spectral absorption coefficient and the solid particle spectral absorption coefficient and spectral scattering coefficient; obtaining grid information and light ray information to determine the incident point of the light entering the jet flow field; simulating the transmission of light in the flow field and the process of attenuation events through a probability model, and outputting the simulation results to obtain the jet thermal radiation density.

[0041] The Monte Carlo method is to emit light from the target surface, trace its path in reverse, and use the inverse principle in radiation transfer to process the direction of various scattering events until the light is absorbed or escapes the flow field. Then, the incident path is traced forward from the absorption point to the receiving point, and the thermal radiation contribution of the absorption point to the receiving point is recorded. The reverse Monte Carlo method is more suitable for the situation where a large volume area radiates a small area. When the receiving area is very small relative to the thermal radiation source, it will greatly improve the simulation efficiency. According to the characteristics of rocket jets expanding at high altitudes, it is practical to use the reverse Monte Carlo method to calculate the influence of jet gases and solid particles on the bottom thermal radiation.

[0042] Specifically, such as Figure 2 As shown in Figure 2, the calculation ideas of the reverse Monte Carlo method for simulating engine jet thermal radiation include:

[0043] 1) Establish a coordinate system for the entire system;

[0044] 2) Establish the field of view angle in the local coordinate system of the observation point and calculate the solid angle of the field of view;

[0045] 3) Use two random numbers to determine the azimuth and circular angle of the light in the local coordinate system. Based on these two angles, the direction of the emitted energy beam in the system coordinate system can be calculated. Then, combined with the system coordinates of the observation point, all the information of a ray can be obtained.

[0046] 4) Determine the incident point of the light entering the jet flow field based on the known flow field grid information and light ray information;

[0047] 5) Calculate the attenuation coefficient of the plume in the incident direction, combine it with the random number to give the transmission distance between the two events, and then determine the location coordinates of the next event based on the radiation direction;

[0048] 6) If light is scattered by particles (only particles can scatter light; gas molecules do not), it is necessary to determine the particle size that caused the scattering. Then, a new azimuth and circumference angle are generated based on the pre-given scattering phase function and random numbers, and the light continues to propagate in a straight line, starting from the point where the scattering occurred.

[0049] 7) If absorbed by particles, it is necessary to determine which particle size produces the absorption effect, and then calculate the directional thermal radiation intensity of the particles based on the temperature of the absorption unit and the wavelength under investigation. This is the thermal radiation intensity that can reach the receiving surface (observation point);

[0050] 8) If absorbed by gas, the thermal radiation intensity is calculated based on the gas radiation characteristics, temperature, etc.;

[0051] 9) If the light escapes the jet flow field, the spectral radiation intensity is zero;

[0052] 10) If no attenuation event (absorption and scattering, collectively referred to as attenuation events) occurs in the cell, the light must leave the cell. At this time, it is necessary to determine which cell the light enters after leaving the cell.

[0053] 11) Repeat the above process to count and output the simulation results.

[0054] According to the above simulation steps, it can be seen that when light passes through the flow field, it needs to pass through multiple judgments of the probability model, which can be used Figure 3 The process of light transmission in the flow field and attenuation events is shown.

[0055] Corresponding to Figure 3 ,in,

[0056] Azimuth angle θ and circular angle Calculation formula:

[0057] θ=arccos[1-R θ (1-cosθ max )]

[0058]

[0059] Where: θ max is the half angle of the field of view; R θ and are all random numbers uniformly distributed between [0,1].

[0060] The total radiation heat flux is:

[0061]

[0062] Where: I e The directional spectral radiation intensity emitted by the absorption point in the reverse process; N B is the total number of bands; ΔK=2π(1-cosθ max ) is the solid angle of the field of view of the measuring point on the 2π circle; Δe i is the width of the i-th band; (I e cosθ) i is the average radiation power of the i-wave band within the field of view:

[0063]

[0064] N is the total amount of light absorbed by the gas and particles; θ j I is the angle between the jth ray and the outer normal of the receiving surface; e,b,i,j (T) is the directional spectral radiation intensity of the j-th absorbed light at the absorption point:

[0065]

[0066] c1=3.72×10 -16 Wm 2 , c2=1.438×10 -2 mK,e i is the central wave number of the i-wave band, and T is the temperature of the control body where the absorption point is located.

[0067] After tracking a large number of light rays, the heat flux density of the system reaching the measuring point can be calculated using the above formula.

[0068] Among them, the main input parameters include: the gas radiation characteristics of each node calculated by the gas radiation characteristics calculation module, the particle radiation characteristics of each node calculated by the particle radiation characteristics calculation module, and the control parameters of the receiving point (the total number of rays emitted by each emission point, the square parameter of the receiving point, and the azimuth angle).

[0069] Second embodiment

[0070] Based on the same concept, the present invention also provides a launch vehicle engine jet thermal radiation analysis system, including: a grid division module, used to establish a local coordinate system including a coordinate origin and a coordinate direction, and perform surface grid division and volume grid division based on the local coordinate system; a gas radiation characteristic calculation module, used to obtain the gas spectral absorption coefficient of each node in the volume grid based on the spectral absorption coefficient database and the input flow field parameters; a particle radiation characteristic calculation module, used to calculate the spectral scattering cross section and spectral absorption cross section based on the spectral scattering factor, spectral absorption factor and solid particle diameter of the solid particles, and calculate the spectral absorption coefficient and spectral scattering coefficient of the solid particles in combination with the particle number density; a heat flux density calculation module, used to simulate and calculate the jet thermal radiation density based on the gas spectral absorption coefficient and the spectral absorption coefficient and spectral scattering coefficient of the solid particles using the inverse Monte Carlo method.

[0071] The engine radiation characteristics analysis is completed through surface mesh division, volume mesh division, and automatic calling of gas radiation characteristics calculation, particle radiation characteristics calculation and engine thermal radiation calculation programs in the background.

[0072] The meshing module is used to mesh the solid walls and boundary walls of the computational region, as well as the volume mesh of the computational region. The gas radiation characteristics calculation module is used to calculate the gas thermal radiation characteristics of different gas components within the computational region. The particle radiation characteristics calculation module is used to calculate the radiation characteristics of solid motor combustion particles. The heat flux density calculation module is used to calculate the heat flux density of the focus point in the computational region affected by gas and solid particles. Through the integration and coordination of these modules, rapid analysis of jet thermal radiation can be achieved.

[0073] In one embodiment of the present invention, a data management module is further included, which is used to store process data and input data during the operation of the analysis method and display the process data and input data according to a preset mode.

[0074] The data management module is used to store calculation results and conduct comparative analysis of multiple calculation conditions. The platform display interface displays input parameters, grids, calculation result curves, etc., which can achieve better visualization effects.

[0075] Third embodiment

[0076] Based on the same concept, the present invention also provides an electronic device, comprising: a memory for storing a processing program; and a processor for implementing any one of the above-mentioned methods for analyzing the jet thermal radiation of a carrier rocket engine when executing the processing program.

[0077] Based on the same concept, the present invention also provides a readable storage medium, on which a processing program is stored. When the processing program is executed by a processor, any one of the above-mentioned methods for analyzing the jet thermal radiation of a carrier rocket engine is implemented.

[0078] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, if these changes fall within the scope of the claims of the present invention and their equivalents, they still fall within the scope of protection of the present invention.

Claims

1. A method for analyzing the thermal radiation of a launch vehicle engine jet, characterized in that: include: Establishing a local coordinate system including a coordinate origin and a coordinate direction, and performing surface meshing and volume meshing based on the local coordinate system; Calculating and obtaining the gas spectral absorption coefficient of each node in the volume grid based on the spectral absorption coefficient database and the input flow field parameters; The spectral scattering cross section and spectral absorption cross section are calculated based on the spectral scattering factor, spectral absorption factor and solid particle diameter of the solid particles, and the spectral absorption coefficient and spectral scattering coefficient of the solid particles are calculated in combination with the solid particle number density; Based on the gas spectral absorption coefficient and the solid particle spectral absorption coefficient and spectral scattering coefficient, the jet thermal radiation density is simulated and calculated using the reverse Monte Carlo method; The calculation of the spectral scattering cross section and the spectral absorption cross section based on the spectral scattering factor, the spectral absorption factor and the diameter of the solid particles, and the calculation of the spectral absorption coefficient and the spectral scattering coefficient of the solid particles in combination with the number density of the solid particles include: Obtain the refractive index and absorption coefficient of solid particles, and use Mie scattering theory to calculate their spectral scattering factor and spectral absorption factor; Calculate the spectral scattering cross section and spectral absorption cross section based on the solid particle spectral heat dissipation factor and spectral absorption factor combined with the solid particle diameter; Based on the spectral scattering cross section and the spectral absorption cross section, the spectral absorption coefficient and the spectral scattering coefficient of the solid particles are calculated in combination with the solid particle number density.

2. The method for analyzing the jet thermal radiation of a carrier rocket engine according to claim 1, characterized in that: After the jet thermal radiation density is calculated by using the reverse Monte Carlo method, the method further includes: storing process data and input data during the running of the analytical method; The process data and the input data are displayed according to a preset mode.

3. The method for analyzing the jet thermal radiation of a carrier rocket engine according to claim 1, wherein: The performing of surface mesh division and volume mesh division based on the local coordinate system includes: Input coordinate system definition, surface equation, surface normal direction, surface meshing method, surface temperature, solid wall emissivity, and surface-to-surface interface method; Performing surface network division based on the coordinate system definition, surface equation, surface normal direction, surface mesh division method, surface temperature, solid wall emissivity, and surface-to-surface interface method; Input the volume mesh region and mesh division rules, and divide the 3D volume mesh inside the region based on the volume region composed of various faces.

4. The method for analyzing the jet thermal radiation of a carrier rocket engine according to claim 1, wherein: The obtaining of the gas spectral absorption coefficient of each node in the volume grid based on the spectral absorption coefficient database and the input flow field parameters includes: Call the spectral absorption coefficient of the target gas at the target wave number and target temperature in the HITRAN and HITEMP databases; Perform difference calculation on target node parameters to obtain the spectral absorption coefficients of different gases; The spectral absorption coefficients of different gases are integrated to obtain the gas spectral absorption coefficient of the target node.

5. The method for analyzing the jet thermal radiation of a carrier rocket engine according to claim 1, wherein: The jet thermal radiation density is calculated by using the reverse Monte Carlo method based on the gas spectral absorption coefficient and the solid particle spectral absorption coefficient and spectral scattering coefficient, including: Obtaining the gas spectral absorption coefficient and the solid particle spectral absorption coefficient and spectral scattering coefficient; Obtain grid information and light ray information to determine the incident point of the light entering the jet flow field; The propagation of light in the flow field and the process of attenuation events are simulated through a probabilistic model, and the simulation results are output to obtain the jet thermal radiation density.

6. A launch vehicle engine jet thermal radiation analysis system, characterized in that: include: A meshing module, configured to establish a local coordinate system including a coordinate origin and a coordinate direction, and perform surface meshing and volume meshing based on the local coordinate system; a gas radiation characteristic calculation module, configured to obtain the gas spectral absorption coefficient of each node in the volume grid based on a spectral absorption coefficient database and input flow field parameters; The particle radiation characteristic calculation module is used to calculate the spectral scattering cross section and spectral absorption cross section based on the spectral scattering factor, spectral absorption factor and solid particle diameter of the solid particles, and calculate the spectral absorption coefficient and spectral scattering coefficient of the solid particles in combination with the particle number density; a heat flux density calculation module, configured to calculate the jet thermal radiation density by using a reverse Monte Carlo method based on the gas spectral absorption coefficient and the solid particle spectral absorption coefficient and spectral scattering coefficient; The calculation of the spectral scattering cross section and the spectral absorption cross section based on the spectral scattering factor, the spectral absorption factor and the diameter of the solid particles, and the calculation of the spectral absorption coefficient and the spectral scattering coefficient of the solid particles in combination with the number density of the solid particles include: Obtain the refractive index and absorption coefficient of solid particles, and use Mie scattering theory to calculate their spectral scattering factor and spectral absorption factor; Calculate the spectral scattering cross section and spectral absorption cross section based on the solid particle spectral heat dissipation factor and spectral absorption factor combined with the solid particle diameter; Based on the spectral scattering cross section and the spectral absorption cross section, the spectral absorption coefficient and the spectral scattering coefficient of the solid particles are calculated in combination with the solid particle number density.

7. The launch vehicle engine jet thermal radiation analysis system according to claim 6, characterized in that: The method further comprises a data management module for storing process data and input data during the running of the analysis method and displaying the process data and the input data according to a preset mode.

8. An electronic device, characterized in that: include: a memory for storing a processing program; A processor, which implements the launch vehicle engine jet thermal radiation analysis method as described in any one of claims 1 to 5 when executing the processing program.

9. A readable storage medium, characterized in that: The readable storage medium stores a processing program, and when the processing program is executed by the processor, the carrier rocket engine jet thermal radiation analysis method according to any one of claims 1 to 5 is implemented.

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