Numerical Simulation Of Infrared Radiation Plume Calculations

The numerical calculation of plume infrared radiation is a main method to research on infrared radiation characteristics of high-speed flight target, It has high research meaning for infrared detection and tracking of targets. Compared with the field test, numerical calculation has great advantage on cost savings and improve efficiency, but for a general engineering calculation, often because more approximate exists in modeling, it is difficult to make a more accurate description to the radiation characteristics of the target. Based on this, this paper carried out against the research of high reliability modeling calculation of the target’s plume radiation.Precisely describing radiation characteristics of the target’s plume ofen needs to obtain two parameters of tail flame. One is calculating the flow field parameters of the tail flame radiation, the second is to calculate the radiation transmission of radiation parameters. In view of the flow field parameters, the computational fluid dynamics software simulation method is applied in this paper to obtain the concrete data of a certain type of missile. The calculated spectrum radiation parameters are obtained by calling the spectral line parameters HITRAN database and using line by line integral method to calculate. The two access methods are high precision at present, thus ensuring the precision of source data.In addition, in the aspect of data processing, due to the large number of complicated flow field data involved in the computation is not convenient, this paper adopts the method of 3D data processing, implants the whole flow field data and the target model into three-dimensional scene, and uses the WYSIWYG philosophy to extract gaze direction flow field data, which improves the data extraction precision and the computation efficiency. Compared with the general method, this method is the more flexible and more extensible, moreover, it also can be based on this method to solve the problem of identifying projection area under the condition of the tail flame blocked by complex model.After detailed processing of radiation calculation data, this paper takes advantage of the C-G band model method to solve the radiative transfer equation, and get the observed radiation distribution along any direction. When making specific calculation, it makes one direction of the radiation calculation equivalent to the calculation of several parallel line of sight, using the ideas of partitioned summation, considering the influence of different areas on the whole, and improving the calculation precision.This paper starts from the basic theory, the basic process of numerical calculation of plume radiation was given, the factors affecting the accuracy of the calculation process are analyzed in detail, and gives many effective solutions to problems in the process of calculation, fundamentally improve the calculation of radiation characteristics of target plume precision, provides certain reference value for establishing high confidence of target radiation characteristic computing model. At the same time, it has certain enlightenment function to study the infrared detection and tracking and other military applications.