Fig. 1. Schematic diagram of the jet

Fig. 2. Schematic diagram of jet field calculation domain

Fig. 3. Schematic diagram of the IR calculation domain

Fig. 4. Spectral radiation intensity distribution of domain IR_5 with sample number 370 and 570

Fig. 5. Temperature distributions on the center section of the flow field

Fig. 6. Spectral IR intensity between 3-5 μm band

Fig. 7. Mean and fluctuation root mean square of integrated radiation intensity between 3-5 μm band

Fig. 8. Mean IR radiation brightness in the detection field

Fig. 9. Radial profiles of radiation brightness mean at different axial locations

Fig. 10. IR radiation brightness fluctuation in the detection field