Abstract: The QUICK and finite volume method, RNG k-ε turbulence model, wall functions, discrete ordinates method (DOM) and the weighted-sum-of-gray-gases model (WSGGM) were employed to solve N-S equation, thermal conduction equation in solid wall and radiation transfer equation. A converging nozzle with chevron trailing edge was simulated, and the computed results were validated with available experimental data. The internal and external flow field and infrared characteristics of a converging-diverging nozzle with or without chevron trailing edge were simulated. The result of this research shows that the chevrons induce streamwise vortices into the shear layer, which lead to increased mixing and is benefit to the reduction of infrared radiation of the plume especially near to the nozzle exit.