The axisymmetric convergent-expansion nozzle exhaust system of a certain turbofan engine was taken as a prototype wherein the film cooling schemes on the central-cone surface were numerically investigated by CFD/IR methods. The cooling schemes were compared and the cooling action of central-cone surface on the infrared radiation characteristics was revealed. The results show that the film cooling on the central-cone surface could effectively decrease the surface temperature

and suppress the infrared radiation intensity between 0 degree and 15 degree viewed from backward direction. The best cooling scheme achieved about 282K decrease on the central-cone surface as well as 57% relative decrease of infrared radiation intensity on 0 degree direction by comparing with the prototype exhaust system.