Study On The Surrogate Model Of Radiation Characteristics Of High Temperature Gas

The calculation of radiation characteristics of high temperature gas is widely used in various fields,such as infrared feature detection of high-speed targets.Combined with the traditional calculation method of gas radiation characteristic parameters,it is of great significance to study the calculation method of high temperature gas radiation characteristic parameters with higher calculation efficiency.In this paper,the line by line method with the highest accuracy is studied firstly,and the correctness of the line by line program is verified by calculating the radiation characteristic parameters of single uniform gas and mixed gas through the line by line method,which is consistent with the experimental results in the literature.Then,malkmus statistical narrow band model is established based on the latest high-resolution spectral database hitemp-2010,and the program for solving the model parameters is compiled The correctness of malkmus statistical narrow band program is verified by the results of line by line under different working conditions of volume and single non-uniform gas.Based on the two temperature model and the line by line method,the narrow band k distribution database of CO₂,CO and H₂ O gas thermodynamics is established.The vibration temperature range of the database is 200-3000 K,the interval is 100 K,the rotation temperature range is 200-3000 K,the interval is 100 K,a total of 335 temperature points,the narrow-band resolution is 5cm-1.The database is verified,and the general situation and the use of the database are introduced.Taking RBF neural network as the proxy model method,the structure,principle and learning mode of RBF neural network are studied.The proxy model of absorption coefficient of CO₂ and H₂ O gas in 3400-3800cm-1 band is constructed respectively.The input parameters of proxy model are temperature,pressure and mole fraction,and the output parameters have a narrow-band resolution of 5cm-1 absorption coefficient Compared with the calculation method,the agent model has higher calculation efficiency and takes up less memory while ensuring the accuracy.Combining the agent model with the radiation transfer model,the temperature and the mole fraction of the gas change dramatically in the calculation of the radiation transfer,so it is assumed that the temperature and the mole fraction of the gas obey the linear distribution and the Gaussian distribution respectively,and the spectral radiation intensity is calculated under different distribution types and different gas path lengths.By comparing the agent model with the narrow-band K-distribution method,the light The root mean square error of spectral radiation intensity is very small,and the relative error of spectral band integral value of spectral radiation intensity is about 2%,which is of great significance for the study of radiation heat flow.Meanwhile,it also reflects that the error of proxy model will not be amplified with radiation transmission,and it has good adaptability in gas transmission,and it can be extended to more gas molecules and more Large band range.