Research On The Infrared Radiation Characteristic Of Hypersonic Aircraft Plume

With the rapid development of hypersonic aircrafts and its great advantage in military, to detect and intercept it in time becomes extremely urgent. Among all the frequently used methods of target detection, infrared detection is developed vigorously because it’s hidden, sensitive and of high adaptability. Plume of hypersonic aircrafts has high temperature, and contain intense radiative component such as 2H O, therefore it is main radiative source during infrared detection. Since it is of high difficulty to catch the hypersonic aircraft’s infrared signal due to its flexibility and fast speed, further research on its infrared study is extremely necessary.In this paper, numerical simulation and radiation properties of hypersonic aircraft plume were studied so as to provide a basis for infrared detection. The main works was as follows:A numerical simulation model for hypersonic aircraft plume based on computational fluid dynamics(CFD) was built, and the changing characteristic of near-field plume with flight condition was studied. Moreover, a simulation method by segmenting the computational domain for far-field plume is proposed, and far-field plume properties along the direction of its length was also studied in this paper. I also built a radiation transfer model for hypersonic aircraft plume base on Line of Sight(LOS) method, and wrote a radiation calculating program. Radiation changing properties with detecting angel and wave band, as well as the changing characteristic along plume length direction, were studied, too.Furthermore, a high-definition digital earth model was built combining remote sensing images. A radiation calculating model for earth surface was made by associating earth surface type, temperature and radiation properties to the digital mode, and thus hypersonic aircraft plume above different earth backgrounds were calculated. Since the refractive index of plume is different from that of environment air, doing research on the influence of plume flow filed on background’s radiation image is also necessary.Research in this paper contributes to the target infrared detection, and provides theoretical basis and application value for goal early warning and interception.