A kind of unconventional serpentine two-dimensional(2-D) nozzle was designed to suppress the infrared radiation characteristics of an axisymmetric exhaust system.Based on the distribution of temperature

pressure and species mass fraction of the exhaust system obtained from CFD results

the infrared radiation characteristics of the axis nozzle and serpentine 2-D nozzle were calculated with reverse Monte-Carlo method

then analyzed and compared with the 2-D nozzle.The results show that

serpentine 2-D nozzle are capable of shielding the high temperature elements inside the exhaust system effectively

and the infrared radiation characteristics of the exhaust system is further suppressed much more

as the core passage flow and bypass flow mixing is enhanced by the help of its three-dimensional flow effect compared with the 2-D nozzle. Meanwhile

the infrared suppression goes better as the offset increases.Compared with the axis nozzle

the infrared radiation characteristics of the exhaust system reduces by more than 70% on average

while the thrust loss is less than 3%.