Abstract:

For mastery of infrared radiation spectral characteristics and intensity distribution of exhaust plume of a rectangular nozzle, a geometrical model of a rectangular nozzle was established. Software Flu- ent6. 3 was used to simulate the 3-D exterior flow field of the rectangular nozzle, and the data of the flow field, such as temperature, pressure and density, was obtained, and the computational area of infrared radiation was established according to the characteristics of the rectangular nozzle plume. A statistical narrow-band model with Lorentzian profile was used to obtain the mean absorption coefficients of the plume in a narrow band. Then Finite Volume Method was used to solve the radiative transfer equations with gas medium. Finally, the spectral characteristics and the total intensity distribution in 3 ~5 滋m of exhaust plume radiation were obtained. The results show that the plume is flat, the infrared radiation in- tensity on the symmetry surface of wide side is greater than that of narrow side, and two peaks of plume infrared radiation emerge in 2. 7 滋m and 4. 3 滋m.

Key words: optics, exhaust plume, rectangular nozzle, radiative transfer equation, finite volume meth- od, infrared radiation