The infrared signature in 3~5μm band of an axisymmetric nozzle was calculated by a three-dimensional code to investigate the improvement of Tam-Ganesan turbulence model in the infrared radiation (IR) of aircraft exhaust system.The flow fields of nozzle were simulated by the finite volume method (FVM)

coupled with the standard k-ε turbulence model and Tam-Ganesan model respectively.The infrared signature of the exhaust system was calculated by FVM in non-gray absorbing-emitting media coupled with narrow band model (NBM).The final infrared signature has considered the atmosphere effect.A standard k-ε model was also investigated by being compared with the Tam-Ganesan turbulence model.The Tam-Ganesan turbulence model provided improved mean flow and infrared radiation predictions related to the standard model.It is shown the application of the optimal turbulence model is vital to the calculation of infrared radiation characteristics of exhaust system.