CN-122021036-A - Method for predicting infrared spectrum radiation distribution characteristics of decoy bomb multiple radiation sources

Abstract

The invention relates to the technical field of decoy bomb infrared spectrum radiation characteristics, in particular to a method for predicting the infrared spectrum radiation distribution characteristics of a plurality of radiation sources of a decoy bomb, which is suitable for calculating the infrared spectrum radiation characteristics of the decoy bomb under the condition of dynamic combustion under the condition of no power source flight after the decoy bomb is actually launched by a carrier, not only considers the dynamic characteristics of the bomb in the actual dynamic flight process of the decoy bomb, but also considers the interaction mechanism among a plurality of radiation sources formed by solid pyrotechnic charge burning surfaces, high-temperature gas molecules, solid combustion particles and other participative mediums in the decoy bomb combustion flow field, has the characteristic of efficiently and accurately predicting the infrared spectrum radiation characteristics of the decoy bomb, and solves the problem that the decoy bomb infrared spectrum radiation distribution characteristics are difficult to accurately predict in real time under the dynamic flight condition in the prior art.

Inventors

• ZHANG KANGKANG
• SUN ZIWEI
• DING CHENG
• LU QIAN
• WANG DONG

Assignees

• 安徽工业大学

Dates

Publication Date

20260512

Application Date

20260203

Claims (6)

1. 1. A method of predicting the infrared spectral radiation distribution characteristics of a decoy bomb multiple radiation source, the method comprising the steps of: S1, establishing a dynamic model of a bait bomb body in a three-dimensional scene, and calculating the speed information of bomb body movement of the bait bomb body in a dynamic combustion process after being transmitted by a carrier, wherein the speed information comprises speed, acceleration and displacement information of the bait bomb body in three directions of a three-dimensional coordinate system x, y and z; S2, establishing a solving model of the dynamic combustion multi-physical field coupling of the bait bullet, obtaining a speed inlet boundary condition of a calculation domain by solving the dynamic model conversion of the bait bullet body, and solving the space-time distribution characteristics of the bait bullet during combustion under the dynamic flight condition; S3, establishing a calculation model of infrared spectrum radiation physical parameters of the decoy bomb multiple radiation sources, and respectively calculating the spectrum radiation physical parameters of a solid explosive column combustion surface and a participatory medium of the decoy bomb in a combustion flow field through the calculation model, wherein the participatory medium comprises high-temperature gas molecules and solid combustion particles; s4, establishing an infrared radiation transmission equation comprehensively considering the emission, absorption and scattering effects of the participatory medium, reading the multi-physical-field information of the combustion flow field and the spectral radiation physical parameters of the participatory medium, and performing decoy bomb multi-radiation source infrared spectral radiation characteristic coupling calculation.
2. 2. A method for predicting the infrared spectral radiation distribution characteristics of a lure bomb multiple radiation source according to claim 1, wherein said step S1 comprises the steps of: S11, carrying out stress analysis on the bait bullet in a three-dimensional scene, and respectively calculating the motion acceleration of the bullet body in the three directions of x, y and z in a Cartesian coordinate system by considering the influence of air resistance, gravity, emission parameters and the speed and the gesture of a carrier during emission, wherein the calculation formula is as follows: ; wherein ρ a is the atmospheric density, g is the gravitational acceleration, v a is the instantaneous velocity of the lure bullet relative to the surrounding atmosphere, a ref is the effective resistance area, C d is the air resistance coefficient, m is the mass of the lure bullet, and α and β are the launch depression angle and the deflection angle, respectively; S12, setting environmental parameters and emission condition parameters, wherein the environmental parameters comprise altitude, environmental pressure, air temperature and atmospheric density, and the emission condition parameters comprise emission angle, emission speed and carrier flight speed; After the bait bullet is launched by the carrier, the motion characteristic parameters in the full life cycle of the flying combustion without a power source are collected, the speed and displacement information of the bait bullet body in three directions of a three-dimensional coordinate system x, y and z are written as user-defined functions, and the user-defined functions are used as the boundary conditions of the calculation domain entrance of a solving model of the dynamic combustion multi-physical field coupling of the bait bullet under the three-dimensional coordinate system so as to reproduce the complex airflow conditions during the actual dynamic combustion of the bait bullet.
3. 3. A method for predicting the infrared spectral radiation distribution characteristics of a lure bomb multiple radiation source according to claim 1, wherein said step S2 comprises the steps of: S21, establishing a solution model of coupling of a bait bullet dynamic combustion multi-physical field under a three-dimensional coordinate system, specifically, establishing a solution model frame of coupling of a bait bullet pyrochemical combustion reaction and turbulent flow under a dynamic flight condition based on a finite volume method, wherein the solution model frame of coupling comprises the steps of solving an N-S equation set by adopting a Reynolds averaging method, solving a pyrochemical reaction source item by adopting a vortex dissipation concept combustion model, and solving a turbulent effect of high-temperature gas-phase flame by adopting a Realizable k-epsilon turbulent flow reaction, wherein the solution model vector equation set is as follows: ; Wherein, x, y and z are three directions of a three-dimensional coordinate system respectively, W is a conservation vector variable, F i ,G i and H i are non-viscous vector flux in x, y and z directions of the three-dimensional coordinate system respectively, F v ,G v and H v are viscous diffusion vector flux in x, y and z directions of the three-dimensional coordinate system respectively, and S is a chemical reaction source term vector; S22, equivalently converting speed information of speed and displacement of the decoy bomb body in three directions of a three-dimensional coordinate system x, y and z in the step S1 into a speed inlet boundary condition of a combustion flow field calculation domain by a solving model, and solving a solving model of coupling of a plurality of physical fields of dynamic combustion of the decoy bomb based on a computational fluid dynamics method to obtain space-time distribution characteristics of a temperature field, a pressure field, a component field and a particle field of the decoy bomb during combustion under a dynamic flight condition; s23, respectively exporting all the surface elements and the volume elements involved in the combustion flow field in Tecplot and EnSight data files; The Tecplot data file comprises grid types, node coordinates, node composition numbers of the bait bullet solid combustion surface elements and temperature information corresponding to each node; EnSight the data file contains absolute pressure, temperature, gas phase component mole fraction and particle phase component concentration information of the combustion flow field calculation domain geometry file, and establishes a data structure of shielding relation between the surface elements or between the surface elements and the volume elements, and mathematical description of the surface elements and the volume elements is given.
4. 4. A method for predicting the infrared spectral radiation distribution characteristics of a lure bomb multiple radiation source according to claim 1, wherein said step S3 comprises the steps of: S31, calculating spectral radiance I λ,surf of the decoy elastic solid combustion surface according to the law of gray body radiation, wherein the calculation formula is as follows: ; In the formula, Spectral emissivity for a solid combustion surface; A first radiation constant of ; A second radiation constant of ; T is the temperature of the solid combustion surface; S32, the high-temperature gas component of the participation medium in the combustion flow field has strong spectrum selectivity, and the spectrum absorption coefficient of the gas component g is calculated The method specifically comprises the following steps: ; Wherein x i,g is the mole fraction of the gas component g in the ith intersecting voxel, p i,ab and T i,ab are absolute pressure and absolute temperature respectively, alpha i,g is the spectral absorption coefficient of the gas component g at the standard atmospheric pressure and the temperature is T i,ab , and the spectral absorption coefficient is obtained through interpolation calculation; S33, solving spectral radiation physical parameters of solid combustion particles by adopting Mie theory, wherein the spectral attenuation factor Q ext,λ , the spectral scattering factor Q sca,λ and the spectral absorption factor Q abs,λ of single particles are respectively expressed as: ; ; ; In the formula, The method is characterized in that the method is used for obtaining the particle size by taking the dimensional parameter, the particle diameter is D, the complex real part is taken as Re, the Mie scattering coefficients are a n and b n , and the method can be obtained by calculation according to the Ricatti-Bessel function.
5. 5. The method of claim 4, wherein the Ricatti-Bessel function is calculated according to the following formula: ; ; In the formula, N and k are refractive index and absorption index respectively; For the Ricatti-Bessel function, 、 Respectively is 、 Is a derivative of (2); Wherein, ζ n = ψ n -iχ n satisfies the following recurrence relation: ; ; When n=0, the initial value of Ricatti-Bessel function is: 。
6. 6. A method for predicting the infrared spectral radiation distribution characteristics of a lure bomb multiple radiation source according to claim 1, wherein said step S4 comprises the steps of: s41, comprehensively considering the infrared radiation transmission differential equation of the absorption, scattering and emission of the participating media, wherein the differential equation is as follows: ; In the formula, To correspond to wavelength along the omega direction Is a directional spectral radiance of (1); And The spectral absorption coefficient of the medium and the spectral scattering coefficient of the particles; the directional spectrum radiation brightness of the black body along the omega direction; for directional spectral scattering luminance in the Ω' direction, S is the length of the edge; S42, solving an infrared radiation transmission differential equation in a three-dimensional space by adopting a source term six-flow method, wherein the method comprises the steps of firstly obtaining the source term radiation intensity of each voxel based on a forward six-flow method, then solving the radiation intensity in any direction based on a source term invariance principle, simplifying the infrared radiation transmission differential equation into a radiation transmission equation along positive and negative directions of a three-dimensional coordinate system x, y and z, and the method comprises the following steps: ; In the formula, , , Respectively, in positive directions along x, y and z axes, corresponding to wavelength Is a directional spectral radiance of (1); , , respectively, in the negative directions of x, y and z axes, corresponding to wavelength Τ x ,τ y ,τ z is the length of each coordinate axis, Ω f 、Ω b and Ω s are the fractions of anisotropic scattered radiation entering the voxel from the forward direction, backward direction and sideways direction, respectively; The last term of the radiation transmission equation in the six directions is respectively supplemented with the positive and negative directions along the x, y and z axes corresponding to the wavelength The above can be converted into: ; ; ; ; wherein J is positive and negative 6 directions of x, y and z axes under a three-dimensional coordinate system; It can be seen that the same term exists in the 6 radiation transmission equations along the positive and negative directions of the three-dimensional coordinate system x, y and z, namely the generalized radiation source term Sr is: ; the infrared radiation transmission differential equation is discretized by adopting a finite volume method, specifically, the infrared radiation transmission equation along the direction of the detection light L is discretized into a differential format by a windward format, and the differential format is as follows: ; In the formula, A generalized radiation source term for a voxel whose three-dimensional coordinates lie in (i, j, k); For the ith voxel and the (i+1) th voxel along the direction of the detection light L Calculating the difference value of the infrared radiation brightness transmitted in the distance; the brightness of the infrared radiation transmitted by the (i+1) th voxel along the direction of the detection light ray L; The intensity of the infrared radiation transmitted by the ith voxel along the direction of the detection light ray L; the length of the path of the ith voxel along the direction of the detection light ray L; Reading the Tecplot and EnSight data files derived in the step S2, substituting the physical property parameter spectrum scattering factor and spectrum attenuation factor determined in the step S3 and the radiation source item S (i,j,k) of the unit body into an infrared radiation transmission equation which is scattered into a differential format, and completing the numerical solution of the infrared spectrum radiation characteristics of the decoy bomb multiple radiation sources.

Description

Method for predicting infrared spectrum radiation distribution characteristics of decoy bomb multiple radiation sources Technical Field The invention relates to the technical field of decoy bomb infrared spectrum radiation characteristics, in particular to a method for predicting the infrared spectrum radiation distribution characteristics of a plurality of decoy bomb radiation sources. Background In order to improve the viability of the aircraft, decoy ammunition was designed to fight infrared guided weapons as early as the last 50 th century, and to date, the use of decoy ammunition to generate infrared decoy would have led to the infrared guided weapons to be attracted from own aircraft, and still be the most cost effective and widely used countermeasure. Most of the aviation decoy bullets are throwing type combustion type, when the payload of the aviation decoy bullets burns, strong infrared radiation can be generated in a specific wave band to form infrared spectrum radiation characteristics of decoy or coverage target aircrafts, the combustion process of the decoy bullets is accompanied by intense energy release and other forms of electromagnetic radiation, the combustion temperature of the decoy bullets is generally higher than 2000K, the infrared radiation of the decoy bullets has obvious multi-radiation source characteristics, the radiation mainly originates from solid combustion surfaces of pyrotechnic grains, high-temperature gas molecules, solid combustion particles and other participating mediums in a combustion flow field, the radiation interval covers a near-middle-far infrared wave band (0.8 mu m-14 mu m), the infrared radiation mechanism and the infrared spectrum radiation characteristics of the decoy bullets are researched, and an effective means can be provided for infrared interference efficiency evaluation and target infrared characteristic analysis. The method for acquiring the infrared spectrum radiation characteristics of the decoy bullet mainly comprises an external field test and numerical simulation, wherein the external field test can acquire the truest and most accurate infrared radiation characteristic data, but external conditions are difficult to change continuously in the test process, the conditions such as weather, time and equipment are difficult to ensure at the same time, the external field test needs to bear more manpower, time and other costs, and the numerical simulation is to establish a decoy bullet infrared spectrum radiation characteristic prediction model through theoretical modeling and numerical simulation, can simulate the infrared characteristics under different conditions, has the advantages of high repeatability, low cost, comprehensiveness and high visualization degree, and is favored by researchers. The method for determining the relationship between the particle radius and the infrared radiation intensity through the least square method comprises the steps of establishing an infrared decoy bullet tail flame flow field model and a simple hole type nozzle model based on a DPM model, simulating the radiation model of the infrared decoy bullet based on the DPM model, researching the radiation characteristics of the decoy bullet under different conditions, and determining the relationship between the particle radius and the infrared radiation intensity through the least square method; However, the infrared decoy radiation intensity calculation model does not consider complex pyrotechnic combustion chemical reaction, the decoy surface temperature is calculated only through an energy conservation equation, the decoy is equivalent to blackbody radiation treatment, the infrared spectrum characteristics of the decoy can not be described, the DPM model strengthens mathematical description of the decoy load combustion process, but the model ignores the actual dynamics characteristics of the decoy, the characteristics of multiple radiation sources are not considered in the modeling process, the influence on the decoy radiation characteristics under the dynamic flight condition can not be analyzed, in sum, the defects that the infrared spectrum radiation characteristics of the decoy bullet, the influence on the dynamic flight condition and the like can not be analyzed exist in the conventional decoy infrared radiation characteristic calculation method of the decoy bullet, the model calculation accuracy is limited, and the evaluation work of the use efficiency of the decoy bullet under the complex working condition in practical application is difficult to develop. Disclosure of Invention In order to solve the technical problems in the prior art, the invention provides a method for predicting infrared spectrum radiation distribution characteristics of a plurality of decoy ammunition radiation sources. In order to solve the technical problems, the invention provides the following technical scheme that the method for predicting the infrared spectrum radiation distributio