A numerical study was conducted on infrared radiation characteristics in the waveband of 3~5μm for two-dimensional plug nozzle of a turbofan engine

which was compared with an axisymmetric converge-diverge nozzle.The results reveal that:compared to axisymmetric converge-diverge nozzle

there is only a limited range of detecting angle

where the two-dimensional plug nozzle has infrared restraining effect.The infrared radiation of two-dimensional plug nozzle decreases 54% as the detecting angle equals to 90° on the narrow detecting side.On the condition that the back wall temperature of plug decreases 300K

the two-dimensional plug nozzle has visible infrared restraining effect on most detecting angle;moreover

its infrared radiation intensity decreases 57% towards the aft-nozzle.