A method and device for calculating the infrared radiation characteristics of a solid rocket engine exhaust plume

Abstract

The application provides a method for calculating the infrared radiation characteristics of the plume of a solid rocket engine. The method comprises: obtaining the outlet parameters and the external flow field parameters of the solid rocket engine; calculating the solid particle density and temperature of a plurality of spatial points in the external flow field along the outlet axis of the engine according to the outlet parameters and the external flow field parameters; interpolating the solid particle density and temperature of the plurality of spatial points in the external flow field by using a cubic spline function to obtain the density and temperature distribution of all solid particles in the external flow field; and calculating the radiation characteristics of all solid particles in the full spatial region of the external flow field based on the density and temperature distribution of all solid particles in the external flow field to determine the infrared radiation characteristic distribution of the plume of the solid rocket engine. The method can significantly improve the calculation efficiency of the infrared radiation characteristics of the plume of the solid rocket engine.

Description

Technical Field

[0001] This invention relates to the field of infrared radiation characteristics technology, and in particular to a method and apparatus for calculating the infrared radiation characteristics of the exhaust plume of a solid rocket engine. Background Technology

[0002] The exhaust plume of a solid rocket motor contains a variety of physical field coupling phenomena, and the calculation process for its infrared radiation characteristics is complicated and time-consuming.

[0003] In related technologies, computational fluid dynamics (CFD) is commonly used to calculate the infrared radiation characteristics of solid rocket motor exhaust plumes. Although this method is relatively accurate, its computational efficiency is low.

[0004] Therefore, there is an urgent need to provide a new method and apparatus for calculating the infrared radiation characteristics of solid rocket motor exhaust plumes. Summary of the Invention

[0005] To address the problem of low computational efficiency in calculating the infrared radiation characteristics of solid rocket motor exhaust plumes, this invention provides a method and apparatus for calculating the infrared radiation characteristics of solid rocket motor exhaust plumes.

[0006] In a first aspect, embodiments of the present invention provide a method for calculating the infrared radiation characteristics of the exhaust plume of a solid rocket engine, the method comprising:

[0007] Obtain the outlet parameters and external flow field parameters of the solid rocket motor;

[0008] Based on the engine outlet parameters and the external flow field parameters, calculate the density and temperature of solid particles at multiple spatial points in the external flow field along the engine outlet axis;

[0009] The density and temperature of solid particles at multiple spatial points in the external flow field are interpolated using cubic spline functions to obtain the density and temperature distribution of all solid particles in the external flow field.

[0010] Based on the density and temperature distribution of all solid particles in the external flow field, the radiation characteristics of all solid particles in the entire space region of the external flow field are calculated to determine the infrared radiation characteristic distribution of the exhaust plume of the solid rocket motor.

[0011] Secondly, embodiments of the present invention also provide a calculation device for the infrared radiation characteristics of the exhaust plume of a solid rocket engine, the device comprising:

[0012] The acquisition unit is used to acquire the solid rocket motor's outlet parameters and external flow field parameters.

[0013] The first calculation unit is used to calculate the density and temperature of solid particles at multiple spatial points in the external flow field along the engine outlet axis, based on the engine outlet parameters and the external flow field parameters.

[0014] The second calculation unit is used to interpolate the density and temperature of solid particles at multiple spatial points in the external flow field using a cubic spline function, so as to obtain the density and temperature distribution of all solid particles in the external flow field.

[0015] The third calculation unit is used to calculate the radiation characteristics of all solid particles in the entire space region of the external flow field based on the density and temperature distribution of all solid particles in the external flow field, so as to determine the infrared radiation characteristic distribution of the exhaust plume of the solid rocket engine.

[0016] Thirdly, embodiments of the present invention also provide a computing device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, it implements the method described in any embodiment of this specification.

[0017] Fourthly, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to perform the methods described in any embodiment of this specification.

[0018] This invention provides a method and apparatus for calculating the infrared radiation characteristics of solid rocket motor exhaust plumes. First, the temperature and density of solid particles at multiple spatial points in the external flow field at the engine exit axis are solved layer by layer. Then, cubic spline functions are used to interpolate multiple density and temperature ranges of solid particles in the external flow field to construct a mapping relationship between solid particle density and temperature along the engine axis. Based on the distance between any spatial point in the external flow field and the engine exit, and the mapping relationship between solid particle density and temperature, the density and temperature of all solid particles in the external flow field are obtained. Finally, based on the density and temperature distribution patterns of all solid particles in the external flow field, the radiation characteristics of the solid particle field of a solid rocket motor under high-altitude conditions can be rapidly calculated, reducing the calculation time to the minute level. This significantly improves the calculation efficiency of the infrared radiation characteristics of solid rocket motor exhaust plumes. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1This is a flowchart of a method for calculating the infrared radiation characteristics of a solid rocket motor exhaust plume according to an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of the distribution of solid particles in the exhaust plume of a solid rocket engine provided by an embodiment of the present invention;

[0022] Figure 3 A schematic diagram of the distribution of solid particles in the exhaust plume of another solid rocket engine provided by an embodiment of the present invention;

[0023] Figure 4 A schematic diagram of the calculation logic for the density and temperature of solid particles at multiple spatial points in the external flow field along the engine axis, provided in an embodiment of the present invention;

[0024] Figure 5 A density and temperature variation curve at a spatial point along the engine outlet axis provided in one embodiment of the present invention;

[0025] Figure 6 This is a hardware architecture diagram of a computing device provided in an embodiment of the present invention;

[0026] Figure 7 This is a structural diagram of a calculation device for the infrared radiation characteristics of the exhaust plume of a solid rocket engine, provided in an embodiment of the present invention. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] Please refer to Figure 1 This invention provides a method for calculating the infrared radiation characteristics of the exhaust plume of a solid rocket engine. The method includes:

[0029] Step 100: Obtain the solid rocket motor exit parameters and external flow field parameters;

[0030] Step 102: Based on the engine outlet parameters and the external flow field parameters, calculate the density and temperature of solid particles at multiple spatial points in the external flow field along the engine outlet axis.

[0031] Step 104: Use a cubic spline function to interpolate the density and temperature of solid particles at multiple spatial points in the external flow field to obtain the density and temperature distribution of all solid particles in the external flow field.

[0032] Step 106: Based on the density and temperature distribution of all solid particles in the external flow field, calculate the radiation characteristics of all solid particles in the entire space region of the external flow field to determine the infrared radiation characteristic distribution of the exhaust plume of the solid rocket engine.

[0033] In this embodiment of the invention, the temperature and density of solid particles at multiple spatial points in the external flow field at the engine exit axis are first solved layer by layer. Then, cubic spline functions are used to interpolate the density and temperature ranges of multiple solid particles in the external flow field to construct a mapping relationship between the density and temperature of solid particles along the engine axis. Thus, based on the distance between any spatial point in the external flow field and the engine exit, and the mapping relationship between the density and temperature of solid particles, the density and temperature of all solid particles in the external flow field are obtained. Finally, based on the density and temperature distribution law of all solid particles in the external flow field, the radiation characteristics of the solid particle field of a solid rocket engine under high-altitude conditions can be rapidly calculated, and the calculation time can be shortened to the minute level. This significantly improves the calculation efficiency of the infrared radiation characteristics of the exhaust plume of a solid rocket engine.

[0034] For step 100:

[0035] In some embodiments, the solid rocket motor exit parameters include the mass flow rate of the solid particles, the motor exit diameter, the expansion half-angle, the solid particle size, the solid particle density, and the motor exit temperature; the external flow field parameters include the external flow field axis length and the calculation step size.

[0036] In this embodiment, as Figure 2 As shown, firstly, based on the engine's operating mechanism, a model of the engine's outlet section and external flow field region is constructed to determine the outlet parameters and external flow field parameters of the solid rocket engine.

[0037] Regarding step 102:

[0038] In this embodiment, considering that the gas temperature in the exhaust plume of a solid rocket engine drops rapidly in a high-altitude environment, and its infrared radiation characteristics are mainly manifested as the radiation characteristics of solid particles, this embodiment only considers the density and temperature of solid particles in the engine exhaust plume. By appropriately simplifying the exhaust plume of a solid rocket engine in the high-altitude flow domain, the density and temperature distribution of all solid particles in the external flow field can be obtained by mapping the density and temperature of solid particles at multiple spatial points in the external flow field along the engine exit axis. This allows for the determination of the infrared radiation characteristic distribution of the solid rocket engine exhaust plume, which greatly improves computational efficiency.

[0039] In some implementations, step 102 includes:

[0040] With the engine outlet position as the center, the external flow field is divided into multiple spherical caps with different radii;

[0041] Based on the engine outlet parameters and the external flow field parameters, calculate the density and temperature of the spatial points where each spherical surface intersects with the engine outlet axis.

[0042] In this embodiment, based on the mass conservation equation and the basic principle of radiation heat dissipation, the density and temperature distribution functions of multiple spatial points in the external flow field at the engine outlet axis are constructed, thereby calculating the density and temperature of solid particles at multiple spatial points.

[0043] First, density calculation formulas are constructed for multiple spatial points in the external flow field along the engine axis. In the high-altitude flow region, the resistance of solid particles is very small; therefore, the jet velocity of the solid particles is assumed to be constant. To improve computational efficiency, the external flow field region is divided into multiple concentric spherical caps with different radii, centered at the engine outlet. Solid particles are ejected from the engine outlet at a certain flow rate. According to the mass conservation equation, such as… Figure 2 As shown, the flow rate of solid particles is the same on the cross-sections of spherical caps with different radii in the external flow field, which satisfies the following formula:

[0044]

[0045] In the formula, and Let represent the solid particle flow rates at cross-sections i and j, respectively. Each cross-section represents a sphere centered at the engine outlet center; therefore, the particle flow rates on the i and j spheres are the same. Furthermore, the solid particle flow rate can be expressed as a function of density ρ, i.e.

[0046]

[0047] Therefore, by transforming the above formula, we can obtain the formula for calculating the density of the spatial points where each spherical surface intersects with the engine outlet axis:

[0048]

[0049] S i =2πL i (L i -L i cos(α exit ))

[0050] In the formula, ρ i Let be the density of solid particles at the spatial point where the i-th spherical cap surface intersects with the engine outlet axis. Let v be the solid particle flow rate at the i-th spherical cap cross section. i Let S be the velocity of the solid particle at the i-th spherical cap cross section.i Let L be the cross-sectional area of ​​the i-th spherical cap. i To calculate the step size, α exit To expand half an angle.

[0051] Next, temperature calculation formulas are constructed for multiple spatial points in the external flow field along the engine axis. In the temperature calculation, it is assumed that solid particles cool only through radiation and that the temperatures of particles do not affect each other. Therefore, the temperature distribution of solid particles in the external flow field at the engine outlet is only related to distance. Thus, the center of the engine outlet can be used as the center point, dividing the external flow field region into multiple concentric spherical caps with different radii. The temperature of solid particles at any point on the same spherical cap is equal. Therefore, the temperature of the spherical cap cross-section can be used as an equivalent to the temperature of the spatial point where the spherical cap surface intersects with the engine outlet axis.

[0052] It is worth noting that if a spatial point P in the external flow field region is near the engine outlet, the spherical calculation formula will be affected by the outlet size. Therefore, a limitation is imposed if L <d exit If the area is 2 / 2, then the area of ​​the spherical cap is replaced by the cross-sectional area of ​​the exit. That is, the area S at this point... i Represented as

[0053] S i =π(d exit / 2+L i tan(α exit )) 2 .

[0054] like Figure 3 As shown, if multiple concentric spherical cap sections with different radii are divided into layers 1, 2, ..., i, ..., n from the engine outlet outwards, then according to the principle of radiative heat flow calculation, the particle temperature of the i-th layer can be calculated from the particle temperature of the (i-1)-th layer. Therefore, in this embodiment, a recursive formula can be used to calculate the density and temperature of solid particles at multiple spatial points in the external flow field along the engine axis. For example, as... Figure 4 As shown, the function T = T_cal(varargin) can be used. In this function, it is first necessary to determine the input variable varargin. If the variable varargin contains only one variable, it can be determined as the starting point of recursion. In this case, T1 = T, where T is the temperature of the engine outlet. If the variable varargin contains 2, then the 2 variables represent the number of the spherical cap section i and the temperature TN_1 of the previous spherical cap section, respectively. Then, the temperature value T of the i-th spherical cap section can be calculated by subtracting ΔT from the temperature TN_1 of the previous spherical cap section. i .

[0055] Specifically, the calculation strategy for the temperature value Ti of the i-th layer spherical cap section is as follows:

[0056] Radiative heat flux of solid particles:

[0057] q i =4πεC0(T i-1 / 100) 4 (d particle / 2) 2

[0058] In the formula, q i Let E be the radiative heat flux of the i-th layer spherical cap cross section. bi For the radiative force of solid particles, d particle ε is the particle size of the solid particle; ε is the emissivity of the solid particle; and C0 is the blackbody radiation coefficient, which is 5.67 W / (m²). 2 ·K 4 ), T i-1 The temperature of the (i-1)th layer of the spherical cap cross section is denoted as .

[0059] Therefore, over a distance of unit length Δx, the heat loss of a single solid particle is:

[0060] Q i =q i Δx / v

[0061] In the formula, Q i Let represent the heat dissipated by the solid particles in the i-th layer, and v represent the velocity of the solid particles.

[0062] The temperature decrease of the particles in the i-th layer is ΔT i for:

[0063]

[0064] In the formula, m g ρ is the mass of a single solid particle; c is the specific heat capacity of the solid particle; particle For the density of a single solid particle, d particle The particle size of the solid particles;

[0065] Therefore, the temperature value T of the i-th spherical interface i The result is: T i =T i-1 -ΔT i T i-1 Let be the temperature of the i-1 layer spherical cap cross section.

[0066] Regarding step 104:

[0067] Since any spatial point within the external flow field region can establish a connection with the engine outlet axis, and the density and temperature at any point on the same spherical crown surface are the same, in this embodiment, a cubic spline function is used to interpolate the solid particle density and temperature at multiple spatial points in the external flow field along the engine outlet axis obtained in step 102, thereby establishing a mapping relationship between the solid particle density and temperature at multiple spatial points and the engine outlet axis. Furthermore, the density and temperature distributions of all solid particles in the external flow field can be obtained by using this mapping relationship and the distance between any spatial point in the external flow field region and the engine outlet axis; thus, the calculation efficiency can be greatly improved.

[0068] It should be noted that in the calculation model of the solid particles in the external flow field of the engine in this embodiment, the solid particle material is ejected uniformly along a straight line at the engine nozzle outlet, and the maximum distribution range of the particles is restricted by the expansion half-angle of the outlet; therefore, the calculation equation of the inclined line at the outermost side of the engine outlet, which is the constraint of the maximum distribution region of the solid particle distribution, is:

[0069] Y = tan(α exit )X + d exit / 2

[0070] In the formula, α exit is the expansion half-angle, d exit is the engine nozzle diameter, X is the axial distance of the nozzle, and the starting position is the center of the nozzle outlet; when the ordinate yi of the spatial point in the external flow field region is < Y, it is determined that the solid particle is in the external flow field region.

[0071] In some embodiments, step 104 includes:

[0072] Using a cubic spline function to interpolate the density and temperature at each adjacent spatial point along the engine outlet axis respectively, to obtain the density values and temperature values at multiple interpolated spatial points;

[0073] Fitting the density values and temperature values at the multiple interpolated spatial points respectively, to obtain the density and temperature change curves at the spatial points along the engine outlet axis;

[0074] Based on the density and temperature change curves of the spatial points, the distance between any spatial point in the external flow field and the engine outlet center position, calculate the density and temperature distributions of all solid particles in the external flow field.

[0075] In this embodiment, since the multiple spatial points obtained in step 10i , ρ i ] and [L i T i Its distribution curve is as follows: Figure 5 As shown; for example, to calculate the density and temperature of any spatial point P(x0, y0) within the external flow field region, we can first calculate the distance of spatial point P(x0, y0) from the center of the engine outlet:

[0076]

[0077] As analyzed in step 102, on a spherical cap with the same radius, the density and temperature at any spatial point are the same. Therefore, solving for the density and temperature of spatial point P is equivalent to solving for the density and temperature of the spatial point where the spherical cap with radius l intersects the engine outlet axis. Thus, the density and temperature of spatial point P(x0, y0) can be obtained through the density and temperature variation curve of spatial points along the engine outlet axis (i.e., Figure 5 This can be determined from the information provided.

[0078] In summary, this embodiment, while adhering to basic physical laws, appropriately simplifies the calculation model of the external flow field of the solid rocket motor exhaust plume in the high-altitude flow domain through reasonable methods. This significantly improves the efficiency of calculating the infrared radiation characteristics of the solid rocket motor exhaust plume while ensuring the accuracy of the results.

[0079] In some implementations, the expression for the cubic spline function is as follows:

[0080]

[0081] In the formula, h i =x i -x i-1 .

[0082] Regarding step 106:

[0083] In some embodiments, the radiation characteristics of all solid particles in the entire space region of the external flow field are calculated using the following formula:

[0084] a=κ λ +σ sλ ,

[0085]

[0086] In the formula, I λ,LLet σ be the spectral radiation intensity of a solid particle at any spatial point in the external flow field at wavelength λ and optical thickness L, σ be the emissivity of the solid particle, c1 be the first radiation constant, c2 be the second radiation constant, T be the temperature of the solid particle at any spatial point in the external flow field, and λ be the wavelength. λ,0 Let κ be the initial spectral radiance, a be the first coefficient, L be the optical thickness, and κ be the initial spectral radiance. λ σ is the absorption coefficient. sλ C is the scattering coefficient. abs,λ For the absorption cross section, C sca,λ D is the scattering cross section. particle Let ρ be the particle size of the solid particles, and ρ be the density of the solid particles at any spatial point in the external flow field, m g This represents the mass of a single solid particle.

[0087] In this embodiment, the density and temperature of any spatial point in the external flow field can be solved in step 104. Then, based on the density and temperature of any spatial point in the external flow field region obtained from the solution, the infrared radiation characteristics of any spatial point in the external flow field region can be calculated, thereby determining the distribution of infrared radiation characteristics of solid particles in the external flow field of the solid rocket engine exhaust flame.

[0088] It should be noted that in the expressions for the absorption coefficient and the scattering coefficient, D... paritcle Compared with the particle size d in step 102 particle They have the same meaning.

[0089] like Figure 6 , Figure 7 As shown, this embodiment of the invention provides a calculation device for the infrared radiation characteristics of the exhaust plume of a solid rocket engine. The device embodiment can be implemented through software, hardware, or a combination of both. From a hardware perspective, as... Figure 6 The diagram shown is a hardware architecture diagram of a computing device containing a computing device for calculating the infrared radiation characteristics of a solid rocket engine exhaust plume, as provided in an embodiment of the present invention. (Except for...) Figure 2 In addition to the processor, memory, network interface, and non-volatile memory shown, the computing device in the embodiment may also include other hardware, such as a forwarding chip responsible for processing packets. Taking software implementation as an example, such as... Figure 7 As shown, a logical device is formed by the CPU of its computing device reading the corresponding computer program from non-volatile memory into memory and running it. This embodiment provides a computing device for the infrared radiation characteristics of a solid rocket motor exhaust plume, the device comprising:

[0090] Acquisition unit 301 is used to acquire the solid rocket motor's outlet parameters and external flow field parameters;

[0091] The first calculation unit 302 is used to calculate the density and temperature of solid particles at multiple spatial points in the external flow field along the engine outlet axis based on the engine outlet parameters and the external flow field parameters.

[0092] The second calculation unit 303 is used to interpolate the density and temperature of solid particles at multiple spatial points in the external flow field using a cubic spline function, so as to obtain the density and temperature distribution of all solid particles in the external flow field.

[0093] The third calculation unit 304 is used to calculate the radiation characteristics of all solid particles in the entire space region of the external flow field based on the density and temperature distribution of all solid particles in the external flow field, so as to determine the infrared radiation characteristic distribution of the exhaust flame of the solid rocket engine.

[0094] In this embodiment of the invention, the acquisition unit 301 can be used to execute step 100 in the above method embodiment, the first calculation unit 302 can be used to execute step 102 in the above method embodiment, the second calculation unit 303 can be used to execute step 104 in the above method embodiment, and the third calculation unit 304 can be used to execute step 106 in the above method embodiment.

[0095] In one embodiment of the present invention, the solid rocket motor exit parameters in the acquisition unit 301 include the mass flow rate of solid particles, the exit diameter of the motor, the expansion half-angle, the particle size of solid particles, the density of solid particles, and the temperature of the motor exit.

[0096] The external flow field parameters include the length of the external flow field axis and the calculation step size.

[0097] In one embodiment of the present invention, the first computing unit 302 is configured to perform the following operations:

[0098] With the center of the engine outlet as the center, the external flow field is divided into multiple concentric spherical caps with different radii;

[0099] Based on the engine outlet parameters and the external flow field parameters, calculate the density and temperature of the spatial points where each spherical surface intersects with the engine outlet axis.

[0100] In one embodiment of the present invention, the density of the spatial points where each spherical cap surface intersects with the engine outlet axis is calculated using the following formula:

[0101]

[0102] S i =2πL i (L i -L i cos(α exit ))

[0103] In the formula, ρ i Let be the density of solid particles at the spatial point where the i-th spherical cap surface intersects with the engine outlet axis. Let v be the solid particle flow rate at the i-th spherical cap cross section. i Let S be the velocity of the solid particle at the i-th spherical cap cross section. i Let L be the cross-sectional area of ​​the i-th spherical cap. i To calculate the step size, α exit To expand half an angle.

[0104] In one embodiment of the present invention, the temperature of the spatial point where each spherical cap surface intersects with the engine outlet axis is calculated using the following formula:

[0105] T i =T i-1 -ΔT i

[0106] ΔT i =Q i / m g / c,

[0107] In the formula, T i T represents the temperature of the solid particle at the spatial point where the i-th spherical cap surface intersects with the engine outlet axis. i-1 Let ΔT be the temperature value of the solid particle at the spatial point where the (i-1)th spherical cap surface intersects with the engine outlet axis. i Let Q be the temperature difference between the solid particles between the i-th and (i-1)-th spherical cap surfaces. i Let m be the heat lost by the solid particles at the i-th spherical cap cross-section. g Let be the mass of a single solid particle, c be the specific heat capacity of the solid particle, ε be the emissivity of the solid particle, and C0 be the blackbody radiation coefficient, which has a value of 5.67 W / (m²). 2 ·K 4 ), ρ particle For the density of a single solid particle, d particle Let be the particle size of the solid particle, v be the velocity of the solid particle, Δx be the unit length, and T1 be the temperature T at the engine outlet.

[0108] In one embodiment of the present invention, the second computing unit 303 is configured to perform the following operations:

[0109] The density and temperature of each adjacent spatial point along the engine outlet axis are interpolated using a cubic spline function to obtain multiple interpolated density and temperature values ​​of the spatial point.

[0110] The density and temperature values ​​of multiple interpolated spatial points are fitted to obtain density and temperature variation curves of spatial points along the engine outlet axis.

[0111] Based on the density and temperature change curves of the spatial points and the distance between any spatial point in the external flow field and the engine outlet position, the density and temperature distribution of all solid particles in the external flow field are calculated.

[0112] In one embodiment of the present invention, the expression of the cubic spline function is as follows:

[0113]

[0114] In the formula, h i =x i -x i-1 .

[0115] In one embodiment of the present invention, the radiation characteristics of all solid particles in the entire space region of the external flow field are calculated by the following formula:

[0116] a=κ λ +σ sλ ,

[0117]

[0118] In the formula, I λ,L Let σ be the spectral radiation intensity of a solid particle at any spatial point in the external flow field at wavelength λ and optical thickness L, σ be the emissivity of the solid particle, c1 be the first radiation constant, c2 be the second radiation constant, T be the temperature of the solid particle at any spatial point in the external flow field, and λ be the wavelength. λ,0 Let κ be the initial spectral radiance, a be the first coefficient, L be the optical thickness, and κ be the initial spectral radiance. λ σ is the absorption coefficient. sλ C is the scattering coefficient. abs,λ For the absorption cross section, C sca,λ D is the scattering cross section. particle Let ρ be the particle size of the solid particles, and ρ be the density of the solid particles at any spatial point in the external flow field, m g This represents the mass of a single solid particle.

[0119] It is understood that the structures illustrated in the embodiments of the present invention do not constitute a specific limitation on a computing device for calculating the infrared radiation characteristics of a solid rocket motor exhaust plume. In other embodiments of the present invention, a computing device for calculating the infrared radiation characteristics of a solid rocket motor exhaust plume may include more or fewer components than illustrated, or combine some components, split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0120] The information interaction and execution process between the modules in the above-mentioned device are based on the same concept as the method embodiment of the present invention, and the specific details can be found in the description of the method embodiment of the present invention, and will not be repeated here.

[0121] This invention also provides a computing device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements a method for calculating the infrared radiation characteristics of the exhaust plume of a solid rocket engine according to any embodiment of this invention.

[0122] This invention also provides a computer-readable storage medium storing a computer program. When executed by a processor, the computer program causes the processor to perform a method for calculating the infrared radiation characteristics of the exhaust plume of a solid rocket engine according to any embodiment of this invention.

[0123] Specifically, a system or apparatus equipped with a storage medium may be provided, on which software program code implementing the functions of any of the embodiments described above is stored, and the computer (or CPU or MPU) of the system or apparatus may read and execute the program code stored in the storage medium.

[0124] In this case, the program code read from the storage medium can itself implement the function of any of the above embodiments, and therefore the program code and the storage medium storing the program code constitute part of the present invention.

[0125] Examples of storage media used to provide program code include floppy disks, hard disks, magneto-optical disks, optical disks (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), magnetic tapes, non-volatile memory cards, and ROMs. Alternatively, program code can be downloaded from a server computer via a communication network.

[0126] Furthermore, it should be clear that not only can the program code read by the computer be executed, but also the operating system or other components operating on the computer can be instructed based on the program code to perform some or all of the actual operations, thereby realizing the function of any of the embodiments described above.

[0127] Furthermore, it is understood that the program code read from the storage medium is written to the memory set in the expansion board inserted into the computer or to the memory set in the expansion module connected to the computer. Then, based on the instructions of the program code, the CPU or other components installed on the expansion board or expansion module execute some and all of the actual operations, thereby realizing the function of any of the above embodiments.

[0128] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0129] Those skilled in the art will understand that all or part of the steps of the above method embodiments can be implemented by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it performs the steps of the above method embodiments. The aforementioned storage medium includes various media that can store program code, such as ROM, RAM, magnetic disk, or optical disk.

[0130] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating the infrared radiation characteristics of the exhaust plume of a solid rocket motor, characterized in that, include: Obtain the outlet parameters and external flow field parameters of the solid rocket motor; Based on the engine outlet parameters and the external flow field parameters, calculate the density and temperature of solid particles at multiple spatial points in the external flow field along the engine outlet axis; With the center of the engine outlet as the center, the external flow field is divided into multiple concentric spherical caps with different radii; Based on the engine outlet parameters and the external flow field parameters, calculate the density and temperature of the spatial point where each spherical surface intersects with the engine outlet axis; The density and temperature of each adjacent spatial point along the engine outlet axis are interpolated using a cubic spline function to obtain multiple interpolated density and temperature values ​​of the spatial point. The density and temperature values ​​of multiple interpolated spatial points are fitted to obtain density and temperature variation curves of spatial points along the engine outlet axis. Based on the density and temperature change curves of the spatial points and the distance between any spatial point in the external flow field and the engine outlet position, the density and temperature distribution of all solid particles in the external flow field are calculated. Based on the density and temperature distribution of all solid particles in the external flow field, the radiation characteristics of all solid particles in the entire space region of the external flow field are calculated to determine the infrared radiation characteristic distribution of the exhaust plume of the solid rocket motor.

2. The method according to claim 1, characterized in that, The solid rocket motor exit parameters include the mass flow rate of solid particles, the motor exit diameter, the expansion half-angle, the solid particle size, the solid particle density, and the motor exit temperature. The external flow field parameters include the length of the external flow field axis and the calculation step size.

3. The method according to claim 1, characterized in that, The density of the spatial points where each spherical cap intersects with the engine outlet axis is calculated using the following formula: In the formula, ρ i Let be the density of solid particles at the spatial point where the i-th spherical cap surface intersects with the engine outlet axis. Let v be the solid particle flow rate at the i-th spherical cap cross section. i Let S be the velocity of the solid particle at the i-th spherical cap cross section. i Let i be the cross-sectional area of ​​the i-th spherical cap. L i To calculate the step size, α exit To expand half an angle; And / or, The temperature at the spatial point where each spherical surface intersects with the engine outlet axis is calculated using the following formula: ， , In the formula, T i T represents the temperature of the solid particle at the spatial point where the i-th spherical cap surface intersects with the engine outlet axis. i-1 Let ΔT be the temperature value of the solid particle at the spatial point where the (i-1)th spherical cap surface intersects with the engine outlet axis. i Let Q be the temperature difference between the solid particles between the i-th and (i-1)-th spherical cap surfaces. i Let m be the heat lost by the solid particles at the i-th spherical cap cross-section. g Let be the mass of a single solid particle, and c be the specific heat capacity of the solid particle. Let C0 be the emissivity of the solid particle, and C0 be the blackbody radiation coefficient, with a value of 5.67 W / (m2). 2 ·K 4 ), ρ particle For the density of a single solid particle, d particle Let be the particle size of the solid particle, and v be the velocity of the solid particle. For unit length, T1 = engine outlet temperature T.

4. The method according to claim 1, characterized in that, The expression for the cubic spline function is as follows: In the formula, , , , , , .

5. The method according to claim 1, characterized in that, The radiation characteristics of all solid particles in the entire space region of the external flow field are calculated using the following formula: ， ， ， In the formula, I λ,L Let be the spectral radiation intensity of a solid particle at any spatial point in the external flow field at wavelength λ and optical thickness L. Let c1 be the emissivity of the solid particle, c2 be the first radiation constant, c2 be the second radiation constant, T be the temperature of the solid particle at any spatial point in the external flow field, and λ be the wavelength. λ,0 Let be the initial spectral radiance, 'a' be the first coefficient, and 'L' be the optical thickness. The absorption coefficient is... The scattering coefficient is... For absorption cross section, D is the scattering cross section. particle Let ρ be the particle size of the solid particles, and ρ be the density of the solid particles at any spatial point in the external flow field, m g This represents the mass of a single solid particle.

6. A calculation device for the infrared radiation characteristics of the exhaust plume of a solid rocket motor, used to implement the method as described in any one of claims 1 to 5, characterized in that, include: The acquisition unit is used to acquire the solid rocket motor's outlet parameters and external flow field parameters. The first calculation unit is used to calculate the density and temperature of solid particles at multiple spatial points in the external flow field along the engine outlet axis, based on the engine outlet parameters and the external flow field parameters. The second calculation unit is used to interpolate the density and temperature of solid particles at multiple spatial points in the external flow field using a cubic spline function, so as to obtain the density and temperature distribution of all solid particles in the external flow field. The third calculation unit is used to calculate the radiation characteristics of all solid particles in the entire space region of the external flow field based on the density and temperature distribution of all solid particles in the external flow field, so as to determine the infrared radiation characteristic distribution of the exhaust plume of the solid rocket engine.

7. A computing device comprising a memory and a processor, wherein the memory stores a computer program, and the processor, when executing the computer program, implements the method as described in any one of claims 1-5.

8. A computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to perform the method of any one of claims 1-5.

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