A method and device for calculating the spectral radiation intensity of an engine flame

Abstract

The present invention provides a method and device for calculating the spectral radiation intensity of an engine flame, wherein the method comprises: first determining the input values ​​of the main input parameters of the engine and the target flight altitude of the engine; then obtaining a fitting formula generated in advance for the target flight altitude and the main input parameters; wherein the fitting formula is used to characterize the mapping relationship between the spectral radiation intensity of the flame and the main input parameters; finally, substituting the input values ​​of the main input parameters into the fitting formula, and calculating the spectral radiation intensity of the flame corresponding to the flight altitude. This scheme can quickly calculate the radiation intensity of the flame spectrum of the engine at a certain flight high speed and main input parameters.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of radiation intensity calculation, and in particular to a method, device and storage medium for calculating the radiation intensity of an engine flame spectrum. Background Art

[0002] In the design and performance test of the engine, it is necessary to calculate the radiation intensity of the engine flame spectrum.

[0003] In the prior art, when calculating the radiation intensity of the engine flame spectrum, it is necessary to go through two steps: engine flame flow field calculation and radiation intensity calculation. The calculation of radiation intensity depends on the flow field parameters output by the flame flow field calculation. Therefore, it takes a long time to obtain the radiation intensity.

[0004] Therefore, there is an urgent need for a method and device for calculating the spectral radiation intensity of an engine flame to solve the above technical problems. Summary of the invention

[0005] The embodiment of the present invention provides a method and a device for calculating the radiation intensity of an engine flame spectrum, which can quickly calculate the radiation intensity of an engine flame spectrum.

[0006] In a first aspect, an embodiment of the present invention provides a method for calculating the spectral radiation intensity of an engine flame, comprising:

[0007] Determining input values ​​of major engine input parameters and a target flight altitude for the engine;

[0008] Acquire a fitting formula generated in advance for the target flight altitude and the main input parameters; the fitting formula is used to characterize the mapping relationship between the spectral radiation intensity of the jet flame and the main input parameters;

[0009] The input values ​​of the main input parameters are substituted into the fitting formula to calculate the spectral radiation intensity of the jet flame corresponding to the flight altitude.

[0010] In one possible design, the obtaining of a fitting formula pre-generated for the flight altitude and the main input parameters includes:

[0011] Acquire a first preset number of parameter combinations according to the main input parameters; the parameter combinations include sample input values ​​corresponding to each of the main input parameters;

[0012] For the target flight altitude, calculating the jet flame spectrum radiation intensity corresponding to each parameter combination, determining each parameter combination and the corresponding jet flame spectrum radiation intensity as a sample pair, and obtaining the first preset number of sample pairs;

[0013] The first preset number of sample pairs are used to solve the unknown parameters in the pre-constructed multivariate linear regression equation consisting of the jet flame spectral radiation intensity and the main input parameters, so as to obtain a fitting formula for the jet flame spectral radiation intensity and the main input parameters at the target flight altitude.

[0014] In one possible design, obtaining a first preset number of parameter combinations according to the main input parameters includes:

[0015] Determine the value range corresponding to each main input parameter;

[0016] Within the value range of each main input parameter, using interpolation method, respectively obtain a second preset number of values ​​as sample input values ​​of the corresponding input parameter;

[0017] The sample input values ​​of each input parameter obtained are combined to obtain the first preset number of parameter combinations.

[0018] In one possible design, the step of calculating the spectral radiation intensity of the jet flame corresponding to each parameter combination for the target flight altitude includes:

[0019] Inputting the target flight altitude and each of the parameter combinations into the jet flow field model of the engine, respectively, and calculating the jet flow field parameters corresponding to each of the parameter combinations;

[0020] Each calculated jet flame flow field parameter is input into the radiation intensity calculation software to calculate the jet flame spectrum radiation intensity corresponding to each parameter combination.

[0021] In one possible design, the main input parameters include:

[0022] The propellant, chamber pressure P and flight speed V of the engine; wherein the propellant includes oxidizer AP, aluminum powder AL and adhesive prepolymer HTPB.

[0023] In one possible design, the unknown parameters in the pre-constructed multivariate linear regression equation consisting of the jet flame spectrum radiation intensity and the input parameters are solved to obtain a fitting formula for the jet flame spectrum radiation intensity and the input parameters at the target flight altitude, including:

[0024] Constructing a multiple linear regression equation consisting of the jet flame spectrum radiation intensity I and the main input parameters: I=w0AP+w1AL+w2HTPB+w3P+w4V;

[0025] Where W0~W4 are bias terms, AP, AL, HTPB, P and V represent the parameter values ​​of oxidant, aluminum powder, adhesive prepolymer, chamber pressure and flight speed, respectively;

[0026] Using the first preset number of sample pairs, adopting the least square method to iteratively update and calculate each of the bias items until the change value of each of the bias items is less than a preset value;

[0027] Each of the bias terms W0-W4 finally obtained is substituted into the multivariate linear regression equation to obtain a fitting formula for the jet flame spectrum radiation intensity and the main input parameters.

[0028] In one possible design, the jet flame spectrum is 2-5 μm.

[0029] In a second aspect, an embodiment of the present invention further provides a device for calculating the spectral radiation intensity of an engine flame, comprising:

[0030] A determination module, used to determine input values ​​of main input parameters of the engine and a target flight altitude of the engine;

[0031] An acquisition module, used for acquiring a fitting formula generated in advance for the target flight altitude and the main input parameters; the fitting formula is used for characterizing the mapping relationship between the spectral radiation intensity of the jet flame and the main input parameters;

[0032] The calculation module is used to substitute the input values ​​of the main input parameters into the fitting formula to calculate the spectral radiation intensity of the jet flame corresponding to the flight altitude.

[0033] In a third aspect, an embodiment of the present invention further provides a computing device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method described in any embodiment of this specification is implemented.

[0034] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, enables the computer to execute the method described in any embodiment of this specification.

[0035] The embodiment of the present invention provides a method and device for calculating the spectral radiation intensity of an engine flame, firstly determining the input values ​​of the main input parameters of the engine and the target flight altitude of the engine; then obtaining a fitting formula pre-generated for the target flight altitude and the main input parameters; wherein the fitting formula is used to characterize the mapping relationship between the spectral radiation intensity of the flame and the main input parameters; finally, substituting the input values ​​of the main input parameters into the fitting formula, the spectral radiation intensity of the flame corresponding to the flight altitude is calculated. This scheme can quickly calculate the radiation intensity of the flame spectrum of the engine at a certain flight high speed and main input parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 This is a flow chart of a method for calculating the spectral radiation intensity of an engine flame provided by an embodiment of the present invention;

[0038] Figure 2 is a flow chart of constructing a fitting formula generated for a certain flight altitude and main input parameters provided by an embodiment of the present invention;

[0039] Figure 3 is a normalized comparison diagram of the radiation intensity calculated by the method of the present application and the estimated result provided by an embodiment of the present invention;

[0040] Figure 4 is a deviation diagram of the radiation intensity calculated by the method of the present application and the estimated result provided by an embodiment of the present invention;

[0041] Figure 5 is a hardware architecture diagram of a computing device provided by an embodiment of the present invention;

[0042] Figure 6 It is a structural diagram of a device for calculating the spectral radiation intensity of an engine flame provided by one embodiment of the present invention.

[0043] illustrate: Figure 5 In the figure, “*” is the radiation intensity value calculated using the method of the present application, and “×” is the estimated radiation intensity value. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0045] As mentioned above, in the prior art, when calculating the radiation intensity of the engine flame spectrum, it is necessary to go through two steps: engine flame flow field calculation and radiation intensity calculation. The calculation of radiation intensity needs to rely on the flow field parameters output by the flame flow field calculation. Therefore, it takes a long time to obtain the radiation intensity.

[0046] Therefore, in order to solve the above technical problems, we can consider finding the mapping relationship between the engine flame spectrum radiation intensity and the main input parameters, and then determine the multivariate linear regression equation composed of the flame spectrum radiation intensity and the main input parameters to quickly calculate the flame spectrum radiation intensity.

[0047] The specific implementation of the above concept is described below.

[0048] Please refer to Figure 1 The embodiment of the present invention provides a method for calculating the spectral radiation intensity of an engine flame, the method comprising:

[0049] Step 100, determining the input values ​​of the main input parameters of the engine and the target flight altitude of the engine;

[0050] Step 102, obtaining a fitting formula generated in advance for the target flight altitude and main input parameters; the fitting formula is used to characterize the mapping relationship between the spectral radiation intensity of the jet flame and the main input parameters;

[0051] Step 104: Substitute the input values ​​of the main input parameters into the fitting formula to calculate the spectral radiation intensity of the jet flame corresponding to the flight altitude.

[0052] In the embodiment of the present invention, the input values ​​of the main input parameters of the engine and the target flight altitude of the engine are first determined; then a fitting formula generated in advance for the target flight altitude and the main input parameters is obtained; finally, the input values ​​of the main input parameters are substituted into the fitting formula to calculate the radiation intensity of the jet flame spectrum corresponding to the flight altitude. The method provided in this embodiment can quickly calculate the radiation intensity of the jet flame spectrum under a certain flight high speed and main input parameters of the engine.

[0053] Described below Figure 1 How the various steps are performed.

[0054] First, for step 100, when it is necessary to calculate the radiation intensity of a certain engine flame, it is necessary to first determine the target flight altitude of the engine, then further determine the main input parameters of the engine, and finally, obtain the fitting formula corresponding to the flight altitude.

[0055] Then, for step 102, please refer to Figure 2 , the fitting formula generated for a certain flight altitude and main input parameters can be constructed in the following way:

[0056] Step 200: Obtain a first preset number of parameter combinations according to the main input parameters; wherein the parameter combination includes sample input values ​​corresponding to each main input parameter.

[0057] Specifically, the first preset number of parameter combinations of the main input parameters can be determined in the following manner:

[0058] Determine the value range corresponding to each main input parameter;

[0059] Within the value range of each main input parameter, using interpolation method, respectively obtain a second preset number of values ​​as sample input values ​​of the corresponding input parameter;

[0060] The sample input values ​​of each input parameter obtained are combined to obtain the first preset number of parameter combinations.

[0061] For example, assuming that the A and B parameters are the main input parameters of a certain engine, and their value ranges are 20% to 40% and 40% to 60% respectively, then within the value ranges of the two parameters, the interpolation method can be used to obtain 10 values ​​(i.e., the second preset number) respectively, then for the A parameter, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 48%, 40% can be taken as sample input values, and for the B parameter, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58%, 50% can be taken as sample input values; finally, the sample input values ​​of the A and B parameters are arranged and combined to obtain 100 parameter combinations. In this way, it can be ensured that the selected sample input values ​​and the obtained parameter combinations can evenly cover the value range of each parameter, so that the radiation intensity sample obtained by the parameter combination is more generally applicable.

[0062] It is understandable that for each main input parameter, when taking values, the smaller the interval between values, the more sample input values ​​are obtained, the more representative the parameter combination is, and the more accurate the formula obtained by fitting is, but the amount of calculation is also large. In actual value taking, the user can determine the value density according to the requirements for accuracy, and no specific limitation is made without application. In addition, using the difference method for value taking is a preferred method, and this application is not limited to this.

[0063] Step 202: for the target flight altitude, calculate the jet flame spectrum radiation intensity corresponding to each parameter combination, determine each parameter combination and the corresponding jet flame spectrum radiation intensity as a sample pair, and obtain a first preset number of sample pairs.

[0064] Specifically, the spectral radiation intensity of the jet flame corresponding to each parameter combination at the target flight altitude can be determined in the following manner:

[0065] Input the target flight altitude and each parameter combination into the jet flow field model of the engine, and calculate the jet flow field parameters corresponding to each parameter combination;

[0066] Each calculated jet flame flow field parameter is input into the radiation intensity calculation software to calculate the jet flame spectrum radiation intensity corresponding to each parameter combination.

[0067] In this embodiment, the jet flow field parameters under each parameter combination can be accurately calculated through the engine's jet flame flow field model, and then the flow field parameters are used as input for intensity calculation. The jet flame spectral radiation intensity corresponding to each parameter combination can be calculated, that is, the sample pairs, which serve as input for the subsequent solution of the multivariate linear regression equation.

[0068] Step 204: using a first preset number of sample pairs, solving unknown parameters in a pre-constructed multiple linear regression equation consisting of the jet flame spectral radiation intensity and the main input parameters, and obtaining a fitting formula consisting of the jet flame spectral radiation intensity and the main input parameters at the target flight altitude.

[0069] In this embodiment, by using sample pairs to solve the multivariate linear regression equation, a fitting formula consisting of the flame spectrum radiation intensity and the main input parameters is obtained. The fitting formula is applicable to any input value within the value range of the main input parameters and can quickly calculate the radiation intensity corresponding to the parameter to be calculated.

[0070] In some embodiments, the main input parameters of the engine include:

[0071] The engine's propellant, chamber pressure P and flight speed V; wherein the propellant includes oxidizer AP, aluminum powder AL and adhesive prepolymer HTPB.

[0072] In this embodiment, the main input parameters of the engine are defined to make the scheme clearer and more specific. Specifically, the propellant is a three-component propellant composed of an oxidizer AP, an aluminum powder AL, and an adhesive prepolymer HTPB. According to engineering applications, the formula ratio of the three components can be determined as follows: the oxidizer AP content is about 70%, the aluminum powder AL content is about 8% to 20%, and the adhesive prepolymer HTPB content is about 10%; the flight altitude is 0-30km; the flight speed V ranges from 200-900m / s, and the combustion chamber pressure P ranges from 60-130atm.

[0073] The following uses the five main input parameters as an example to illustrate the process of determining the combination parameters, calculating the jet flame spectrum radiation intensity corresponding to each parameter combination, and determining the sample pairs consisting of each parameter combination and the corresponding jet flame spectrum radiation intensity:

[0074] First, determine the value range corresponding to each main input parameter:

[0075] The value range of the oxidant AP content is 65%-75%;

[0076] The value range of aluminum powder AL content is 8%-20%;

[0077] The value range of HTPB content of adhesive prepolymer is 8-12%;

[0078] The chamber pressure P ranges from 60 to 130 atm;

[0079] The flight speed V range is 200-900m / s;

[0080] Then, within the value range, these five parameters are interpolated according to the value range of ±20%, and m groups of input parameters AP(i), AL(i), HTPB(i), P(i), V(i) are obtained; where i is a natural number from 1 to m;

[0081] Finally, these five groups of parameters are arranged and combined to obtain n groups of parameter combinations F(j)=(AP(j), AL(j), HTPB(j), P(j), V(j)); where j is a natural number from 1 to n.

[0082] After determining these n groups of parameter combinations, the flight altitude of the engine is determined, and the n groups of parameter combinations and the flight altitude are respectively substituted into the engine flame flow field and radiation calculation software, and the radiation intensity I of the n groups of engine flames at the flight altitude is calculated, in units of w / sr, that is, a sample pair consisting of each parameter combination and the corresponding flame spectrum radiation intensity is obtained.

[0083] After the sample pair is determined, step 204, in some embodiments, includes:

[0084] Construct a multivariate linear regression equation consisting of the jet flame spectral radiation intensity I and the main input parameters:

[0085] I=w0AP+w1AL+w2HTPB+w3P+w4V; (1)

[0086] Where w0~w4 are bias terms, AP, AL, HTPB, P and V represent the parameter values ​​of oxidant, aluminum powder, adhesive prepolymer, chamber pressure and flight speed, respectively;

[0087] Using a first preset number of sample pairs, adopting a least square method to iteratively update and calculate each bias item until a change value of each bias item is less than a preset value;

[0088] Each bias term W0-W4 finally obtained is substituted into the multivariate linear regression equation to obtain the fitting formula of the jet flame spectrum radiation intensity and the main input parameters.

[0089] When solving the fitting formula, we can first regard P, AL, HTPB, P, and V as variables x0, x1, x2, x3, and x4, then formula (1) can be written as:

[0090] I=w0x0+w1x1+w2x2+w3x3+w4x4 (2)

[0091] Using the least squares method, let:

[0092]

[0093] Among them, α is the learning rate, which is used to control the weight w j The update speed, I′ (i) is the fitted radiation intensity value, unit is w / sr, x j (i) When n=i, x j The numerical value of is i=1, 2, 3...n, i=1, 2, 3, 4.

[0094] Update iteration w j , when the update before and after w j After basically no longer changing, it is considered that the bias term w j It has reached a convergence state and can stop the iterative update process;

[0095] At this time, the calculated bias terms w0~w4 are substituted into formula (1), and the fitting formula of radiation intensity and input parameters AP, AL, HTPB, P, V is obtained.

[0096] Using this fitting formula, the radiation intensity of the jet flame spectrum under a given parameter combination can be quickly calculated.

[0097] In some embodiments, the engine flame spectrum is 2 to 5 μm, and this spectral range is the main flame range of the engine. Obtaining the fitting formula within this range has greater engineering application value. Of course, the present application is not limited to this.

[0098] Below, in order to illustrate the accuracy of the method for calculating the spectral radiation intensity of the engine flame of the present application, the present application provides a normalized comparison chart of the radiation intensity calculated by the method of the present application and the estimated result for 100 main input parameter combinations when the engine is flying at an altitude of 20 km, as shown in FIG. Figure 3 and Figure 4 As shown, from Figure 3 It can be seen that the radiation intensity calculated by this method is almost the same as the estimated result. Figure 4 It can be seen that the deviation between the radiation intensity calculated by this method and the estimated result ranges from -11.65% to 14%, with an average deviation of 4.46%.

[0099] It can be seen that the radiation intensity calculated using the method of the present application has a high accuracy. Therefore, the radiation intensity of the engine flame spectrum can be quickly calculated using the fitting formula method.

[0100] like Figure 5 , Figure 6 As shown, an embodiment of the present invention provides a device for calculating the spectral radiation intensity of an engine flame. The device embodiment can be implemented by software, or by hardware or a combination of software and hardware. From the hardware level, Figure 5 As shown, it is a hardware architecture diagram of a computing device where a computing device for calculating the spectrum radiation intensity of an engine flame provided by an embodiment of the present invention is located. Figure 5 In addition to the processor, memory, network interface, and non-volatile memory shown in the figure, the computing device in which the device is located in the embodiment may also generally include other hardware, such as a forwarding chip responsible for processing messages, etc. Taking software implementation as an example, Figure 6 As shown, as a device in a logical sense, the CPU of the computing device in which it is located reads the corresponding computer program in the non-volatile memory into the memory and runs it. This embodiment provides a computing device for the spectrum radiation intensity of an engine flame, including:

[0101] A determination module 300, for determining input values ​​of main input parameters of the engine and a target flight altitude of the engine;

[0102] The acquisition module 302 is used to acquire a fitting formula generated in advance for the target flight altitude and the main input parameters; the fitting formula is used to characterize the mapping relationship between the spectral radiation intensity of the jet flame and the main input parameters;

[0103] The calculation module 304 is used to substitute the input values ​​of the main input parameters into the fitting formula to calculate the spectral radiation intensity of the jet flame corresponding to the flight altitude.

[0104] In the embodiment of the present invention, the determination module 300 may be used to execute step 100 in the above method embodiment, the acquisition module 302 may be used to execute step 102 in the above method embodiment, and the calculation module 304 may be used to execute step 104 in the above method embodiment.

[0105] In one embodiment of the present invention, the acquisition module 302 is used to perform the following operations:

[0106] Obtaining a first preset number of parameter combinations according to the main input parameters; the parameter combinations include sample input values ​​corresponding to each main input parameter;

[0107] For the target flight altitude, the jet flame spectrum radiation intensity corresponding to each parameter combination is calculated, and each parameter combination and the corresponding jet flame spectrum radiation intensity are respectively determined as a sample pair to obtain a first preset number of sample pairs;

[0108] By using a first preset number of sample pairs, unknown parameters in a pre-constructed multiple linear regression equation consisting of the jet flame spectral radiation intensity and main input parameters are solved to obtain a fitting formula consisting of the jet flame spectral radiation intensity and main input parameters at a target flight altitude.

[0109] It is to be understood that the structure illustrated in the embodiment of the present invention does not constitute a specific limitation on a device for calculating the spectral radiation intensity of an engine flame. In other embodiments of the present invention, a device for calculating the spectral radiation intensity of an engine flame may include more or fewer components than shown in the figure, or combine some components, or split some components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0110] The information interaction, execution process and other contents between the modules in the above-mentioned device are based on the same concept as the embodiment of the method of the present invention. For specific contents, please refer to the description in the embodiment of the method of the present invention, and no further description is given here.

[0111] An embodiment of the present invention further provides a computing device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, a method for calculating the spectral radiation intensity of an engine flame in any embodiment of the present invention is implemented.

[0112] An embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the processor executes a method for calculating the spectral radiation intensity of an engine flame in any embodiment of the present invention.

[0113] Specifically, a system or device equipped with a storage medium can be provided, on which software program code that implements the functions of any of the above-mentioned embodiments is stored, and a computer (or CPU or MPU) of the system or device can be enabled to read and execute the program code stored in the storage medium.

[0114] In this case, the program code itself read from the storage medium can realize the function of any one of the above-mentioned embodiments, and thus the program code and the storage medium storing the program code constitute a part of the present invention.

[0115] The storage medium embodiments for providing the program code include a floppy disk, a hard disk, a magneto-optical disk, an optical disk (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), a magnetic tape, a non-volatile memory card, and a ROM. Alternatively, the program code can be downloaded from a server computer by a communication network.

[0116] In addition, it should be clear that the functions of any of the above embodiments can be implemented not only by executing the program code read by the computer, but also by enabling an operating system operating on the computer to complete part or all of the actual operations based on instructions from the program code.

[0117] In addition, it can be understood that the program code read from the storage medium is written to a memory provided in an expansion board inserted into the computer or to a memory provided in an expansion module connected to the computer, and then based on the instructions of the program code, a CPU installed on the expansion board or expansion module is enabled to perform part or all of the actual operations, thereby realizing the functions of any of the above-mentioned embodiments.

[0118] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical factors in the process, method, article or device including the elements.

[0119] A person of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk, etc., various media that can store program codes.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating the spectral radiation intensity of an engine flame, characterized in that: include: Determining input values ​​of major engine input parameters and a target flight altitude for the engine; Acquire a fitting formula generated in advance for the target flight altitude and the main input parameters; the fitting formula is used to characterize the mapping relationship between the spectral radiation intensity of the jet flame and the main input parameters; Substituting the input values ​​of the main input parameters into the fitting formula, and calculating the spectral radiation intensity of the jet flame corresponding to the flight altitude; The obtaining of a fitting formula generated in advance for the flight altitude and the main input parameters includes: Acquire a first preset number of parameter combinations according to the main input parameters; the parameter combinations include sample input values ​​corresponding to each of the main input parameters; For the target flight altitude, calculating the jet flame spectrum radiation intensity corresponding to each parameter combination, determining each parameter combination and the corresponding jet flame spectrum radiation intensity as a sample pair, and obtaining the first preset number of sample pairs; Using the first preset number of sample pairs, unknown parameters in a pre-constructed multiple linear regression equation consisting of the jet flame spectrum radiation intensity and the main input parameters are solved to obtain a fitting formula consisting of the jet flame spectrum radiation intensity and the main input parameters at the target flight altitude; The main input parameters include: The propellant, chamber pressure P and flight speed V of the engine; wherein the propellant comprises an oxidizer AP, aluminum powder AL and a binder prepolymer HTPB; The unknown parameters in the pre-constructed multivariate linear regression equation composed of the jet flame spectrum radiation intensity and the input parameters are solved to obtain a fitting formula of the jet flame spectrum radiation intensity and the input parameters at the target flight altitude, including: Constructing a multiple linear regression equation consisting of the jet flame spectrum radiation intensity I and the main input parameters: I=w0AP+w1AL+w2HTPB+w3P+w4V; Where w0~w4 are bias terms, AP, AL, HTPB, P and V represent the parameter values ​​of oxidant, aluminum powder, adhesive prepolymer, chamber pressure and flight speed, respectively; Using the first preset number of sample pairs, adopting the least square method to iteratively update and calculate each of the bias items until the change value of each of the bias items is less than a preset value; Each of the bias terms w0-w4 finally obtained is substituted into the multivariate linear regression equation to obtain a fitting formula for the jet flame spectrum radiation intensity and the main input parameters.

2. The method according to claim 1, characterized in that The obtaining of a first preset number of parameter combinations according to the main input parameters includes: Determine the value range corresponding to each main input parameter; Within the value range of each main input parameter, using interpolation method, respectively obtain a second preset number of values ​​as sample input values ​​of the corresponding input parameter; The sample input values ​​of each input parameter obtained are combined to obtain the first preset number of parameter combinations.

3. The method according to claim 1, characterized in that The step of calculating the spectral radiation intensity of the jet flame corresponding to each parameter combination for the target flight altitude includes: Inputting the target flight altitude and each of the parameter combinations into the jet flow field model of the engine, respectively, and calculating the jet flow field parameters corresponding to each of the parameter combinations; Each calculated jet flame flow field parameter is input into the radiation intensity calculation software to calculate the jet flame spectrum radiation intensity corresponding to each parameter combination.

4. The method according to claim 1, characterized in that: The jet flame spectrum is 2 to 5 μm.

5. A device for calculating the spectral radiation intensity of an engine flame, characterized in that: include: A determination module, used to determine input values ​​of main input parameters of the engine and a target flight altitude of the engine; An acquisition module, used for acquiring a fitting formula generated in advance for the target flight altitude and the main input parameters; the fitting formula is used for characterizing the mapping relationship between the spectral radiation intensity of the jet flame and the main input parameters; A calculation module, used for substituting the input values ​​of the main input parameters into the fitting formula to calculate the spectral radiation intensity of the jet flame corresponding to the flight altitude; The acquisition module is used to perform the following operations: Acquire a first preset number of parameter combinations according to the main input parameters; the parameter combinations include sample input values ​​corresponding to each of the main input parameters; For the target flight altitude, calculating the jet flame spectrum radiation intensity corresponding to each parameter combination, determining each parameter combination and the corresponding jet flame spectrum radiation intensity as a sample pair, and obtaining the first preset number of sample pairs; Using the first preset number of sample pairs, unknown parameters in a pre-constructed multiple linear regression equation consisting of the jet flame spectrum radiation intensity and the main input parameters are solved to obtain a fitting formula consisting of the jet flame spectrum radiation intensity and the main input parameters at the target flight altitude; The main input parameters include: The propellant, chamber pressure P and flight speed V of the engine; wherein the propellant comprises an oxidizer AP, aluminum powder AL and a binder prepolymer HTPB; The acquisition module is used to perform the following operations when solving the unknown parameters in the pre-constructed multivariate linear regression equation composed of the jet flame spectrum radiation intensity and the input parameters to obtain the fitting formula of the jet flame spectrum radiation intensity and the input parameters at the target flight altitude: Constructing a multiple linear regression equation consisting of the jet flame spectrum radiation intensity I and the main input parameters: I=w0AP+w1AL+w2HTPB+w3P+w4V; Where w0~w4 are bias terms, AP, AL, HTPB, P and V represent the parameter values ​​of oxidant, aluminum powder, adhesive prepolymer, chamber pressure and flight speed, respectively; Using the first preset number of sample pairs, adopting the least square method to iteratively update and calculate each of the bias items until the change value of each of the bias items is less than a preset value; Each of the bias terms w0-w4 finally obtained is substituted into the multivariate linear regression equation to obtain a fitting formula for the jet flame spectrum radiation intensity and the main input parameters.

6. A computing device, comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method according to any one of claims 1 to 4 is implemented.

7. A computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, causes the computer to execute the method according to any one of claims 1 to 4.

Images